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UMEÅ UNIVERSITY MEDICAL DISSERTATIONS
New series No 101 - ISSN 0346 - 6612
From the Department of Child and Youth Psychiatry,
University of Umeå, Umeå, Sweden
ADOPTION STUDIES ON
PSYCHIATRIC ILLNESS
Epidemiological, Environmental and
Genetic Aspects
by
Anne-Liis von Knorring
Umeå University
Umeå 1983
ADOPTION STUDIES ON
PSYCHIATRIC ILLNESS
Epidemiological, Environmental and
Genetic Aspects
AKADEMISK AVHANDLING
som med vederbörligt tillstånd av
Medicinska fakulteten vid Umeå universitet
för avläggande av medicine doktorsexamen
kommer att offentligen försvaras i
föreläsningssalen, Psykiatriska kliniken,
torsdagen den 19 maj 1983 kl. 09.15.
av
ANNE-LIIS von KNORRING
med. lic.
Umeå 1983
Umeå University Medical Dissertations New Series No 101-ISSN 0346-6612
ABSTRACT
Adoption studies on psychiatric illness. Epidemiological, environmental,
and genetic aspects.
Anne-Liis von Knorring, Department of Child and Youth Psychiatry,
University of Umeå, S-901 85 Umeå, Sweden.
The aim of this study is to evaluate the outcome of adoptions and to
study the gene-environment influences on psychiatric illness as well
as sick-leave patterns. The material consists of 2 966 adopted persons
born between 1917 and 1949, their 5 932 adoptive parents and 5 438
identified biological parents.
Adopted persons had a higher incidence of personality disorders and
substance abuse than non-adopted controls. Adopted men also had an
increased incidence of neuroses. Adopted women had an increased
sick-leave because of somatic complaints, especially upper respiratory
tract infections and abdominal complaints of short duration. Somatiza­
tion i.e. more than 2 sick-leaves/year because of somatic complaint
together with nervous complaints was more frequent among adopted
women. Women with somatization could be separated into 2 types
according to the pattern of sick-leave. Type 1 ("high frequency")
had frequent sick-leaves for psychiatric, abdominal and back com­
plaints. They also had a high frequency of alcohol abuse. Type 2
("diversiform") had more diverse complaints and had fewer sick-leaves
because of nervous complaints.
High frequency somatizers had biological fathers with teenage onset of
criminality and frequent registrations for alcohol abuse. Diversiform
somatizers had the same genetic background as adopted men with
petty criminality or male limited alcoholism.
No specific genetic influences on treated depression or substance
abuse were found in this study. However, a non-specific vulnerability
of the biological mother influenced on the risk of depression and
substance abuse among adopted women.
There were some indications that placement in the adoptive home
between 6 and 12 months of age was associated with reactive neurotic
depression in adult life. Otherwise early negative experiences in term
of unstable placements before adoption did not significantly influence
on psychiatric illness in adulthood.
Affective
ment for
status in
zation of
disorders in the adoptive father were associated with treat­
depressions or substance abuse in the adoptee. Low social
the part of the adoptive father increased the risk of somati­
both types in the adoptee.
Key words: Adoption - adoption outcome - psychiatric illness - geneenvironment - early experience - somatoform disorders - affective
disorders - substance abuse - sick-leave.
UMEÅ UNIVERSITY MEDICAL DISSERTATIONS
New series N o 101 - ISSN 0346 - 6612
From the Department of Child and Youth Psychiatry,
University of Umeå, Umeå, Sweden
ADOPTION STUDIES ON
PSYCHIATRIC ILLNESS
Epidemiological, Environmental and
Genetic Aspects
by
Anne-Liis von Knorring
IJmeå University
Umeå 1983
2
ABSTRACT
The aim of this study is to evaluate the outcome of adoptions and to
study the gene-environment influences on psychiatric illness as well
as sick-leave patterns. The material consists of 2 966 adopted persons
born between 1917 and 1949, their 5 932 adoptive parents and 5 438
identified biological parents.
Adopted persons had a higher incidence of personality disorders and
substance abuse than non-adopted controls. Adopted men also had an
increased incidence of neuroses. Adopted women had an increased
sick-leave because of somatic complaints, especially upper respiratory
tract infections and abdominal complaints of short duration. Somatiza­
tion i.e. more than 2 sick-leaves/year because of somatic complaint
together with nervous complaints was more frequent among adopted
women. Women with somatization could be separated into 2 types
according to the pattern of sick-leave. Type 1 ("high frequency")
had frequent sick-leaves for psychiatric, abdominal and back com­
plaints. They also had a high frequency of alcohol abuse. Type 2
("diversiform") had more diverse complaints and had fewer sick-leaves
because of nervous complaints.
High frequency somatizers had biological fathers with teenage onset of
criminality and frequent registrations for alcohol abuse. Diversiform
somatizers had the same genetic background as adopted men with
petty criminality or male limited alcoholism.
No specific genetic influences on treated depression or substance
abuse were found in this study. However, a non-specific vulnerability
of the biological mother influenced on the risk of depression and
substance abuse among adopted women.
There were some indications that placement in the adoptive home
between 6 and 12 months of age was associated with reactive neurotic
depression in adult life. Otherwise early negative experiences in term
of unstable placements before adoption did not significantly influence
on psychiatric illness in adulthood.
Affective
ment for
status in
zation of
disorders in the adoptive father were associated with treat­
depressions or substance abuse in the adoptee. Low social
the part of the adoptive father increased the risk of somati­
both types in the adoptee.
Key words: Adoption - adoption outcome - psychiatric illness - geneenvironment - early experience - somatoform disorders - affective
disorders - substance abuse - sick-leave.
3
The present thesis is based on the following papers:
I.
Bohman, M. and von Knorring, A-L.: Psychiatric illness among
adults adopted as infants. Acta Psychiat. Scand. 60, 106-112,
1979.
II.
von Knorring, A-L.. Bohman, M. and Sigvardsson, S.: Early
life experiences and psychiatric disorders: an adoptee study.
Acta Psychiat. Scand. 65, 283-291, 1982.
III. Sigvardsson, S., von Knorring, A-L., Bohman, M., Cloninger,
C. R. : An adoption study of somatoform disorders I. The relation­
ship of somatization to psychiatric disability. Submitted Arch.
Gen. Psychiat.
IV.
Cloninger, CR., Sigvardsson, S., von Knorring, A-L., Bohman,
M.: An adoption study of somatoform disorders II. Identification
of two discrete somatoform disorders. Submitted Arch. Gen.
Psychiat.
V.
Bohman, M., Cloninger, C.R., von Knorring, A-L., Sigvards­
son, S.: An adoption study of somatoform disorders III. Crossfostering analysis and genetic relationship to alcoholism and
criminality. Submitted Arch. Gen. Psychiat.
VI.
von Knorring, A-L., Cloninger, C.R., Bohman, M., Sigvards­
son, S.: An adoption study of depressive disorders and sub­
stance abuse. Submitted Arch. Gen. Psychiat.
4
CONTENTS
GENERAL BACKGROUND
6
Adoption practices in Sweden
Adoption research
6
7
PURPOSE OF THE STUDY
10
REVIEW OF THE LITERATURE
11
Outcome studies of adoptions
Maternal deprivation and psychopathology
The psychotic-neurotic distinction of depression
Genetics of affective disorders
Affective disorders and alcoholism
The transmission of alcohol abuse and criminality
Somatoform disorders and illness behaviour
11
14
16
17
20
21
22
MATERIALS AND METHODS
27
The cohort of adoptees
Register data
Reliability of psychiatric diagnoses
Life events
Statistical analyses
27
28
30
32
32
RESULTS
34
Psychiatric illness among adoptees
Somatic illness among adoptees
The relation of somatic and psychiatric illness
34
34
35
Early childhood experiences and psychiatric disorders
Postnatal childhood experiences and somatization
37
38
Environmental influences on affective disorders and
substance abuse
38
5
Genetic inheritance of affective disorders and substance
39
abuse
Genetic inheritance of somatization
40
Life events related to genetic and/or social predisposition
Gene-environment correlation and interaction of
somatization
41
41
SOURCES OF ERROR
43
DISCUSSION
46
Somatic complaints and psychopathology
46
Environmental influences and psychiatric disability
Genetic influences on psychopathology
48
51
Gene-environment interaction on psychopathology
53
SUMMARY OF THE MAIN RESULTS
57
APPENDIX I
59
ACKNOWLEDGEMENTS
60
REFERENCES
61
Paper I
Paper II
81
89
Paper III
99
Paper IV
Paper V
133
165
Paper VI
201
6
GENERAL BACKGROUND
The practice of adoption occurs in some form in most cultures. In
ancient Rome the law only permitted adoption in the case of childless
couples who needed an heir. The adopters had then to be past childbearing age and the adoptee had to be an adult. The older European
adoption laws were influenced by the Roman law. In North-America,
however, the adoption laws had a different approach. Adoption was
regarded as a way of ensuring a secure home and parentage for a
homeless child.
In Sweden the first adoption law came into force 1917 and was influen­
ced both by Roman law and North-American laws. Adoption according
to the first Swedish law was only permitted if the couple was child­
less. The adoption could be cancelled under certain conditions 1) if
the child turned out to have unknown disablements or diseases 2) if
the parents or the child commited serious offences against each other.
From 1944 onwards couples with biological children were also allowed
to adopt children. In 1958 the adoption law was changed in order to
strengthen the child's legal position in the adoptive family. The
adoptee's ties to biological relatives were totally severed and the
adoptee was granted the same rights in the adoptive family as children
bora of the adoptive parents. Since 1971 it has been impossible to
cancel an adoption. As there have been very few changes in adoption
practices 1917-1949, the cohort of adoptees in this study (born 19171949) show no great differences concerning placement procedure and
selection.
Adoption practices in Sweden
It was estimated that about 1 % of the population was adopted by
couples who were not relatives or step-parents in the 30's and 40's
(Jonsson 1964). Private adoption agencies are prohibited and the
majority of infant adoptions are arranged by the local municipalities of
the child welfare committees. The organization of the adoption agen­
cies varies throughout Sweden but the principal task for each agency
7
is to prepare and participate in the placement of the children. The
work of such an agency also includes assessment of the ability of the
prospective adoptive parents to bring up and take care of the child.
Adoption research
As a ready-made ex-post facto experiment in social and genetic re­
search , the adoptive situation has been used to focus on two main
approaches :
I.
_Studies_of the effect of adoption
Research has for example been carried out to determine which factors
in the child, the adoptive parents and society influence the adoptive
process and to what extent this process can be forecast prior to
placement. Such evaluation studies try to evaluate the extent to which
adoption has been effective as a social measure.
In Sweden the adoptive parents are often older and tend to have a
higher level of education than biological parents. This is a consequen­
ce of the adoption law and of practice. Adoptive parents have to be
at least 25 years old before they are allowed to adopt children. Con­
sequently their marriages are of longer standing than the marriages
which produced biological children (Bohman 1970). Thus it can be
assumed that there is a restriction range in the environmental factors
regarding adopted children. Personal qualities, however, constitute
the most important factor for the development and adjustment of the
adoptee - including the adopters' attitudes to adoption and to illegiti­
mate birth and to infertility. "The age, income and social class of
adopters are of far less importance" (Pringle 1969).
II.
Genetic research
Genetic and environmental factors are difficult to separate, especially
in behavioural sciences. Both social and genetic factors are inherited
but one way to separate them is through adoption studies. Genetically
8
unrelated individuals live together and genetically related individuals
live apart. The adoptive situation is in itself a ready-made experiment
for testing hypotheses concerning the importance of heredity and
childhood environment. These kinds of studies can determine the
extent to which familial resemblances are due to genetic or environ­
mental similarity. The environmental influences distinct from genetic
variables, can be eavlutated - as well as the interaction of genetic
and environmental factors.
The correlation between the adoptee and the biological or adoptive
parents or other environmental variables concerning certain traits or
diseases can be measured. Such studies can start from the adoptees
(the adoptee's families method), or from the parents (the adoptees
study method) (See Fig. 1).
The term "cross-fostering method" is applied to studies in which
postnatal influences can be isolated e.g. by studying adoptees from
an affected biological background reared in a non-affected adoptive
home and vice versa. The prevalence of a trait or disease can thus
be related to both genetic and environmental influences.
9
Adoptees' families' method
0-r-tS
"V
©-—{E
Control
Index
Adoptees study method
O7O
Index
Affected
O Female
• Male
0
Fig. 1.
Either sex
Control
o
Unaffected
•
Individual whose
status is under
investigation
Biological parentage
Adoptive parentage
Research designs of adoption studies (modified from Plomin, DeFries &
McClean 1980).
10
PURPOSE OF THE STUDY
The two main approaches within adoption research (see pp. 6-7) are
employed in this study. The following questions are considered:
Out-come studies
Do adopted persons as adults differ from the general population as
regards :
1.
2.
Psychiatric illness (frequency, duration, pattern)
Somatic complaints (frequency, duration, pattern)
3.
The relation between psychiatric and somatic illness?
Genetic-environmental studies
A.
1.
To what extent are psychiatric illness and/or special patterns of
sick-leave influenced by:
Childhood experiences prior to placement in the adoptive home
2.
Familial environment during childhood and adolescence?
B.
Do genetic factors influence:
1.
Affective disorders and substance abuse
2.
Special patterns of sick-leave?
C.
How is the interaction between genetic and environmental fac­
tors?
11
REVIEW OF THE LITERATURE
Outcome studies of adoptions
As adoption laws and practices vary in time and from country to
country it can be difficult to compare the outcome of adoptions in
different studies.
USA
The earliest follow-up of the long-term out-come of adoptions showed
that the children who had been legally adopted had a better outcome
than foster children (van Theis 1924). This study followed the sub­
jects up to the age of 18-40 years. The better outcome of the adopted
children was attributed to the fact that these children were adopted
and placed in their adoptive homes before the age of 5 years. Only a
small proportion of the adoptees were found "incapable".
Adopted persons had a higher intellectual ability than was to be
expected from the socio-economic status of their biological parents
(Skodak 1949, Skeels 1965).
A 10-year follow-up study concerning private adoptions showed that
70 % of the families functioned satisfactorily (Witmer 1963). The girls
showed a better adjustment than the boys. Compared with a group of
biological children the adopted children seemed to be at a slight
disadvantage regarding personal and social functioning, but not
intellectually. Different results were found in another 10-year followup study (Lawder 1969, Hoopes 1969), which revealed no significant
differences between adopted and biological children concerning beha­
viours rated by parents and teachers.
France
Schiff (1978) studied children of lower class origin who were adopted
early into high status homes and who also |iad a sibling or half-sibling
12
reared by the biological mother. The adopted children had higher IQ
ratings on average than their biological siblings and the children
reared by their biological mothers had far more educational problems.
England
In one study (Seglow 1972) adopted children were compared to the
general population and to children of unmarried women. At the age of
7 the adopted children were better achievers in school than the
illegitimate non-adopted children. The adopted children also turned
out favourably compared to the general population.
Children who had spent their first two years in an institution and
were later adopted, restored to their biological parents or fostered on
a long-term basis were compared in a study by Tizard (1977). The
adoptions were considered successful at an investigation carried out
when the subjects were 8 years old. Compared to the other groups
"adoption was clearly the best solution to the child's need".
A 20-year follow-up study concerning one group of children first
fostered and later adopted and another group immediately adopted as
infants was made by Raynor (1980). Nearly all the children came to
their families during their first year of life and 85 % of the parents
rated the experience of adoption as very satisfactory. There were no
differences between those who had adopted their child directly and
those who had fostered first.
Sweden
An earlier study of adopted persons followed to adulthood showed that
most of the adoptions turned out satisfactorily (Thysell 1952, 1965).
The opportunities offered the adopted children for social, psycholo­
gical and educational development were better than if they had re­
mained with their unmarried mothers. The adoptive parents reported
"some trouble" in 20 % of the cases and "serious problems" in 5 % of
the cases. Problems were more common among the girls.
13
A 10-year follow up study (Bohman 1970, 1971) of adopted children
showed a slight deviation in a negative direction concerning beha­
viour. The deviation was greater for boys. Compared to a group of
foster children the adopted boys had a much better outcome. At the
age of 15 years the adopted children did not differ from their class­
mates. The children in foster-care (although many of them were
adopted at an older age) and the children who stayed with their
biological mothers (although unwanted during pregnancy) tended to
show social maladjustment (Bohman 1972). At the age of 19 it was
found that the boys in foster care and those reared by their biolo­
gical mothers had been rejected for military service for emotional
problems and in some cases intellectual deficiency reasons. The adopt­
ed youngsters had the best outcome in this respect (Bohman 1978a).
During the last few decades the adoption situation has changed in
Sweden in that practically no children born here are adopted away
any more. The reason for this is that abortion is legal for any reason
during the first trimester of the pregnancy. The adopted children
nowadays are mostly from Asia or Latin-America. Follow-up studies
concerning international adoptions have shown that there is a good
outcome if the children are adopted early. If the children go to the
adoptive home at a later age there are more initial problems but as a
whole their adjustment is quite good (Gardell 1979, Cederblad 1979).
In series of psychiatric in- and out-paitents some studies have found
that there is an överrepresentation of adoptees. The frequencies
reported differ from 2.4-13.3 % (Goodman 1963, Schechter 1960). This
is to be compared to the frequency of 1-2 % of adoptees in a normal
population. Other authors have not found any överrepresentation of
adopted adults among psychiatric patients, but on the other hand the
representation of adoptees among Children's Service patients was
twice what would be expected (Brinich 1982).
Conclusions to be drawn from the above mentioned studies: Adopted
persons have a good outcome when compared with persons raised in
fosterhomes or by biological parents from a socially disadvantaged
14
group. Compared to the general population the outcome for adopted
persons is as good or slightly poorer.
Maternal deprivation and psychopathology
The short-term effects of parent-child separation have been described
by many researchers (Spitz 1946, Bowlby 1958, Robertson 1971,
Yarrow 1964), but not all (Davenport 1970). The reaction is most
marked in children aged between six months and four years. Children
differ in their response to separation, because of differences in their
temperamental characterstics before the separation, and because
children used to brief ordinary separations are less distressed by
unhappy traumatic separations (Stacey 1970). According to psychodynamic theory attachment and early bonding to the mother is seen as
the essential precursor to later social relationships (Bowlby 1969,
1973). Infants usually develop an attachment to a specific person at
the age of 6-12 months (Ainsworth 1973, Rutter 1979). The concept of
bonding implies selective attachment which persists over time (Cohen
1974). The difference between attachment and bonding is shown in a
study concerning 4-year-old children reared in institutions who were
more clinging and tended to follow people around more than familyreared children, but they were also less likely to show selective
bonding or deep relationships (Tizard 1975).
Similar results are found in animal studies. Infant Rhesus monkeys
who had experienced more rejection showed more distress after se­
paration (Hinde 1970).
One relevant question in this connection is how childhood experiences
influence personality development. In psychoanalytically oriented
psychiatry it is thought that early childhood experiences bear some
causal relation to psychiatric illness in adult life. The relationship
between parental deprivation and later depression has been widely
studied with parental loss as the experience most commonly assessed.
Psychoanalytical literature suggests that depression is the most likely
outcome of parental loss (Abraham 1927, Freud 1917, Bowlby 1961).
15
The effect of the death of a parent is often studied, because this
event is easily defined. The incidence of parental loss through death
before the age of 15 has been found to be higher among psychiatric
patients in several studies. In studies concerning depressed patients
the patients had experienced bereavement to a greater extent than
controls (Beck 1963, Forrest 1965, Dennehy 1966, Brown 1961, 1966).
Another study showed a correlation between bereavement before the
age of 6 years and recurrent depressive disorders (d'Elia 1971).
Other researchers, however, have not found these correlations at all
(Gregory 1966, Munro 1966, Roy 1978). In most studies separately
defined age ranges for parental loss have not been used and this may
be one reason why the results diverge.
Parental loss has also been shown to be associated with the persona­
lity tfaits of dependency and hypochondriasis (Birchnell 1975, 1978).
This may influénce the utilization of services, but the results are
contradictory concerning the direction. Tennant (1980a, b) found
from a community survey that parent-child separation due to parental
death did not bear any significant relation to psychiatric symptomato­
logy in adult life but was associated with referral to psychiatric
services. On the other hand Brown (1978) found that depressed
persons who had experienced childhood loss were less likely to be
referred to a psychiatrist.
Within a population of depressed patients, those who attempted suicide
showed a higher rate of parental loss than those who did not (Hill
1969). The same association was found among psychoneurotic and
sociopathic patients who attempted suicide (Greer 1964).
Parental loss is not only caused by the death of a parent, it can also
arise through separation but this is more difficult to define. Separa­
tion can take the form of divorce between the parents, but all divor­
ces do not mean that the contact between the parent and child is cut
off. In spite of these difficulties some authors have found a correla­
tion between separation and psychopathology. Paternal loss due to
separation or divorce occurred with much greater frequency among a
16
large in- and out-patient population than in 2 control groups (Brill
1966). This finding occurred in conjunction with a great variety of
diagnoses without any specific category. In a more recent work (Tennant 1982) the relationship of childhood separation to adult depres­
sion, anxiety and 'general psychological morbidity' was assessed.
Childhood separation occurring up to five years of age bore no rela­
tion to psychopathology. From five years of age separations caused
by parental illness were related to morbidity.
Deprivation during childhood does not necessarily result only from
death of a parent or separation. It can also take the form of depri­
vation of loving care or stimulating education towards self-realization.
Depressed patients were found to have experienced the lack, loss or
absence of an emotionally sustaining relationship before adolescence to
a greater extent than controls (Raskin 1971, Jacobson 1975). In the
light of these findings H. Perris (1982a) hypothesized that persons
who had experienced rejection during childhood ought to be more
vulnerable to life events and suffer depressions more easily. Her
results supported the hypotheses. Rejected and depressed patients,
had consistently experienced fewer life events than patients reared by
stimulating mothers.
The psychotic-neurotic distinction of depression
During the last two decades many different classifications for depres­
sive disorders have been proposed. There are classifications which
involve from one up to nine categories (Kendell 1976). There are also
dimensional categories with varying numbers of dimensions. Lewis
(1938) did not think that the existing classifications at that time were
useful. He accepted however that the phenomenology and ethiology of
depressive disorders were heterogeneous. The situation does not seem
to have changed much since then.
Most controversies have been about the psychotic-neurotic (or endo­
genous» reactive) distinction. Confusion has arisen from the change­
able meaning of the term itself (Kendell 1976).
17
There is some association between melancholic symptom cluster and
lack of environmental stress (Rosenthal 1966, Perris H. 1982a), but it
is weak. There is however little relationship between the type and
severity of the preceeding stresses and the symptomatology of the
illness itself (Paykel 1974, Perris H. 1982a). Some studies have been
made which suggest that endogenous and neurotic depressions are
distinct illnesses and that there is a similar clear-cut boundary be­
tween depressive illness as a whole and anxiety states (Carney 1965,
Gurney 1972). Other researchers have tried to show a bimodal distri­
bution of scores on either a bipolar psychotic/neurotic factor or a
discriminant function of symptomatology, but the overall distribution
of symptomatology has tended to be unimodal (Kendell 1970, Ni Bhrolchain 1979).
Genetics of affective disorders
Kraepelin (1921) noted about manic-depressive insanity that a "here­
dity taint" could be demonstrated in the majority of cases.
Two main approaches can be employed in investigating the importance
of the contribution of genetic factors to psychopathology. 1) Clinical
studies which consist of three different methods - family studies, twin
studies and adoptee studies. 2) Biological studies which can be divi­
ded into three categories - association studies, linkage studies and
chromosome studies (Perris C. 1976).
This review is focused on clinical studies. Most genetic studies con­
cerning affective disorders have studied "endogenous" or "primary"
or "major" or "psychotic" affective disorders. In older studies calcu­
lation of the morbidity risk for mano-depressive psychosis (MDP)
among the relatives of patients with MDP disorders have shown very
wide variations. For parents the morbidity risk in different studies
has been 3.4 % - - 23.4 % (Slater 1938, Strömgren 1938, Sjögren 1948,
Stenstedt 1952). For siblings the range was 2.7 % - - 22.7 % (S jögren
1948, Kallmann 1952). For children the range was 6.0 % — 24.1 %
(Stenstedt 1952, Luxemburger 1942). Overall the means are above the
18
median for the general population (0.7 %) (Perris C. 1976).
Leonhard (1957-1969) divided the affective psychoses into bipolar and
unipolar types. The diagnostic criteria based on this classification
have varied in the different studies. Some have labelled patients with
a depressive period and a period of hypomania as bipolar (Weissman
1978, Perris C. 1966) while others have required a major manic and
depressive period before diagnosing bipolar affective disorder (Cloninger 1979). There have also been differences concerning the cri­
teria for unipolar affective disorder. In some studies (Perris C. 1966)
three separate periods were requried and in other studies only one
episode of depression was required (Angst 1966). Both Angst and
Perris found that bipolar subjects had first-degree relatives with
bipolar affective disorder and uni-polar subjects had first-degree
relatives with unipolar affective disorder. This was also confirmed in
a later study (Perris C. 1982).
In more recent family studies the division into unipolar and bipolar is
used also by others. The morbidity risk of affective illness amongst
relatives of bipolar probands is higher than for relatives of unipolar
probands. The risk for siblings of bipolar probands varies from 12.5
% — 42.0 % (Gershon 1977, Winokur 1970a). For parents of bipolar
probands the risk varies between 34.2 % — 41.0 % (Winokur 1970a).
Among siblings of unipolar probands the risk in different studies
varies between 12.9 — 31.3 % (Smeraldi 1977, Mendlewicz 1975) and
for parents 16.0 % — 22.9 % (Shopsin 1976, Winokur 1971a). Unipolar
affective disorders (depression) is very common in the general popu­
lation according to some recent epidemiologic research where more
standardized diagnostic procedures have been used. Helgason (1979)
found a 14.4 % risk of depression for females and an American study
has found even higher life time prevalences women, 25.8 % and men
12.3 % (Weissman 1978). The risk of affective disorder amongst relati­
ves of patients with unipolar illness thus seems not to be much higher
than for the general population. However, the risk of affective illness
amongst relatives of bipolar patients is higher than for the general
population. Thus there is some support for a genetic transmission of
19
bipolar illness but not consistently for unipolar affective disorder.
Twin studies have consistently shown a higher concordance rate for
manic-depressive psychosis or affective psychosis for monozygotic
twins (0.50-0.92) (Harvald 1965, Kallmann 1952). The concordance for
dizygotic twins varied from 0.03 to 0.24. In a later study (Bertelson
1977) it was found that concordance for bipolar illness in monozygotic
twins was 0.79 and in dizygotics 0.19. For unipolar illness the con­
cordance rates were lower: 0.54 in monozygotics and 0.24 in dizygo­
tics.
The classification of depressive disorders has followed a different
course in Europe than in the USA. In Europe unipolar depression has
been kept separate from neurotic-reactive depression (Kielholz 1973,
Angst 1981), while in the USA attention has been focused on primary
and secondary depression (Robins 1972). In DSM-III (1980) dysthymic
disorder is the same as depressive neurosis. The disorder is not
expected to be severe or long enough to be classified as major de­
pression but then it is stated that a duration in adults of 2 years is
required.
A twin study of non-endogenous or reactive depression showed a low
rate of concordance in monozygotic twins (2 of 16 pairs) and no con­
cordance in dizygotic twins (0 of 14 pairs) (Shapiro 1970). In a
family study of neurotic-reactive patients the morbidity risk for
bipolar affective disorder was very low but the overall morbidity risk
of affective disorders was surprisingly high (Perris C. 1982).
Adoption studies on affective disorders are few. Mendlewicz (1977)
studied families of adult bipolar probands who had been adopted
during infancy. The rate of affective disorder among biological pa­
rents was much higher than among the adoptive parents or the bio­
logical parents of normal adoptees or adoptees with poliomyelitis.
Cadoret (1978) studied a small sample of parents and offspring se­
parated early in life by adoption. The results of this study support
the hypothesis of the involvement of a genetic factor in unipolar
20
depressive illness. The Danish adoption studies indicate that there is
an excess of suicide among the biological relatives of adoptees with
affective disorder or other psychiatric disorders leading to suicide
(Kety 1979, Shulsinger 1979).
A stress diathesis model for affective disorders has been described
(Pollitt 1972, Akiskal 1975) in which certain specific life events pre­
cipitate affective disorder in vulnerable individuals. Genetic loading
can be regarded as an important vulnerability factor for the occur­
rence of depression. Pollit found in his study of depression that
severe viral or bacterial infections or other physical stressors and, to
a lesser extent, severe psychological stressors were associated with a
lower morbidity risk in first-degree relatives. On the other hand H.
Perris (1982b) could find no support for this hypothesis in her stu­
dy. Patients with a positive family history of depressive disorders did
not differ significantly from those with a negative family history as
regards the occurrence of life-change events prior to onset of the
illness.
Affective disorders and alcoholism
Alcoholism and affective disorders are reported to occur in the same
individual and in different members of the family more often than is
to be expected by chance (Woodruff 1973, Winokur 1971a, b). Patients
with a family history of alcoholism were more likely to have an early
onset of depression (before the age of 40). The term 'depressive
spectrum disease1 was used for the group of depressed patients who
had relatives who were alcoholics. Suicide is also reported more
frequently among alcoholics, as among depressed patients (Beskow
1981, Dahlgren 1977, Medhus 1974), but there are some contradictory
studies that do not show any higher rates of alcoholism among rela­
tives of patients with affective disorders (Perris C. 1982, Stenstedt
1952). Angst (1966) found a higher morbidity risk of alcoholism among
fathers of depressed patients and neurotic patients. An adoption
study of the daughters of alcoholic biological fathers showed no more
depressions than adopted controls (Goodwin 1977). Genetic marker
21
studies do not provide any consistent evidence of genetic overlap
between alcoholism and depressive disorder or antisocial personality
(Cloninger 1979b).
The conclusion to be drawn from the above-mentioned studies is that
there is a genetic transmission of bipolar affective illness. The results
concerning unipolar affective disorder are not consistent, but most
studies support a genetic transmission. There is little support for thé
hypothesis that alocholism and depression share a common genetic
basis.
The transmission of alcohol abuse and criminality
It is commonly accepted that "alcoholism runs in families" (Jellinek
1945, Åmark 1951, Winokur 1970b). The discussion has centered on
the problem of whether this inheritance is related more to inborn
factors or is rather dependent on sociocultural and psychological
factors. Both twin studies (Kaij 1960, Partanen 1966) and adoption
studies (Bohman 1978b, Cadoret 1978, Goodwin 1973) have supported
the hypothesis that genetic factors contribute to the manifestation of
alcoholism.
In a study using the cross-fostering method (Cloninger 1981) two
types of alcoholism were identified. Both had distinct genetic and
environmental causes. Type 1 (milieu limited type) affected both men
and women and those affected were susceptible to postnatal environ­
mental influences - such as prolonged contact with the biological
mother, late age at placement, several stays in hospital prior to
placement and lower occupational status of adoptive parents. Type 2
alcoholism only affected males. The subjects in this group were less
influenced by postnatal factors but the susceptibility was highly
hereditary from biological fathers. Inheritance from biological mothers
(Bohman 1981) was also important in the development for alcoholism in
women.
22
The concept of alcohol abuse related to criminality has not always
been taken into account when transmission of criminality is studied
(Hutchings 1975). In one study (Bohman 1982) criminality was sepa­
rated from alcohol abuse in the analysis of adopted males. Most vio­
lent crimes were connected with alcohol abuse. Non-alcoholic criminals
were characterized by the commission of a small number of petty
offences. This group of petty criminals had an excess of petty cri­
minality among their biological fathers. The number of unstable preadoptive placements was high in the petty criminality group. Low
socio-economic status was associated with alcohol-related criminality.
Either congenital predisposition or postnatal experiences were shown
to be sufficient for the development of criminality, but specific com­
binations of genetic and environmental antecedents modified the addi­
tive effects of the individual risk factors. There was no genetic
overlap between predisposition to petty criminality and alcoholism
(Cloninger 1982). The congenital predisposition to criminality had to
be more severe for a woman to be affected. Postnatal factors were
more important for the development of criminality than for alcoholism
in women (Sigvardsson 1982b).
Somatoform disorders and illness behaviour
The distinction between somatic and psychiatric disorders is sometimes
hard to make. Pain experience for example is influenced by both an
organic pain generator and by personality characteristics or environ­
mental factors (Mohammed 1978). There is a group of patients for
whom no sure evidence of an organic cause can be found and in whom
all attempts to reveal the cause of the pain fall. Patients in this
group tend to show evidence of primary affective or personality
disorders, including hysteria, conversion reactions, anxiety and
hypochondriasis (Pilowsky 1976). Patients with psychiatric disorders
often have complaints that may suggest somatic diseases (Hagnell
1966).
23
Hysteria
The ancient Greeks considered hysteric phenomena a disorder affect­
ing women attributable to abnormal movements of the uterus (hystera).
The term and diagnosis of hysteria thus has an old tradition, but
there has been much confusion and disagreement about it. Briquet
(1859) in his work described women with "extreme sensitivity of the
nervous system". As a result of this his patients manifested a variety
of pains involving almost every area of the body and they also had
attacks of acute anxiety and sensory-motor paralyses. Somewhat later
Charcot began to study hysteria and tried to understand the causes
of the syndrome. From this the whole psychodynamic psychiatry
movement emerged. Pupils of Charcot, e.g. Janet (1931), contributed
to the theoretical formulations concerning hysteria. Attention slowly
shifted away from clinical diagnostic categories to the psychodynamic
mechanisms that underlay symptoms and that provided at least a
partial causal explanation. This influenced the terms used so that
hysteria became conversion hysteria. Guze (1963) on the other hand
defined "hysteria" as a syndrome which starts early in life, occurring
mainly in females and which shows recurrent symptoms in many differ­
ent organ systems. This syndrome exhibits a certain amount of stabili­
ty and is valid at follow-up (Perley 1962, Martin 1979). The term
"hysteria" thus has many different meanings and this has been con­
fusing and has made it impossible to use the term in scientific or
clinical contexts. According to DSM-III (1980) the syndrome defined
by Perley & Guze (Briquet's syndrome) is called somatization dis­
order. This is a chronic syndrome of recurrent symptoms in many
different organ systems that begins before the age of 30 and is
associated with psychiatric distress but no physical disorder. The
disorder affects women but rare cases in men have been reported.
The utility of a distinction between isolated conversion symptoms and
Briquet's syndrome has been demonstrated by follow-up studies (Martin
1979).
Family studies show that Briquet's syndrome and sociopathy cluster in
the same families instead of segregating as independent traits (Clo-
24
ninger 1975). Women with a definiteci Briquet's syndrome have an
excess of relatives with multiple somatic complaints who often do not
meet the full criteria for the diagnosis (Woerner 1968). There is also
some support for this view provided in 2 adoption studies (Cadoret
1976, Crowe 1974). There were however too few cases in these stu­
dies to permit any firm conclusions.
Hypochondriasis
Gillespie (1928) proposed a strict, clinical definition of this disorder,
which is essentially the same as hypochondriasis according to DSM-III.
Hypochondriasis requires preoccupation with an unrealistic fear or
conviction of having a serious disease and impaired social or occu­
pational function despite medical evaluation and reassurance. This has
been rejected by many investigators, e.g. Kenyon (1976) who suggest­
ed that the term should only be used as a descriptive adjective when
there is a morbid preoccupation with health or body. "Symptom choice
is affected by sociocultural and other variables". Depressive mood is
a frequent accompaniment and he suggested that in many cases the
condition is primarily an affective one.
Masked depression
Masked depression is a condition which manifests itself chiefly at a
somatic level according to Kielholz (1972). Lopez Ibor (1968) pointed
out that the following features are present: phasic course, diurnal
fluctuation, mild inhibition, shift in mood, tiredness, sleep disturban­
ces, loss of concentration and anxious sense of failure. This term
should only be used in connection with the diagnosis of affective
disorders. Even in ordinary depressive syndrome pain is a common
symptom (von Knorring 1975).
Registered_sick-leave and its^ relation to psychiatric and somatic _
disability
In earlier days the most common measure of health or sickness was
25
the mortality figures (Nord-Larsen 1979). Interest has now become
focused on morbidity as well as mortality. Health can be measured in
different ways. It can be "freedom from illness" or defined as positive
health - the best known definition of this kind is that given by WHO
(1958). "Health means more than freedom from disease, freedom from
pain, freedom from untimely death. It means optimum physical, mental
and social efficiency and well-being". But indexes of negative health
may still be useful and there is no need for measures to subdivide
positive health into too many aspects (Brorson 1977). There is a
choice of several available methods for defining the presence or
absence of disease such as the use of interviews, rating scales and
symptom-checklists. Health indexes, a measure which summarizes data
from two or more components and which is supposed to reflect the
health status of an individual or a defined group, can then be used.
In Sweden the sick-listing system can be regarded as a health-index.
All inhabitants over 16 years of age have been covered by compulsory
health insurance since 1955. Anyone who works in the home, is a
student, or has a minimal earning level is financially compensated for
periods of illness. Sick-listing is not an objective measurement. Sickleave can be taken at a person's own discretion for 7 days but a
doctor's note is required from the 8th day onwards. Many factors
influence the taking of sick-leave, personality, social factors and
work conditions are as important as the symptomatology (Nyström
1979b).
Sick-leave is reported to be higher among both male and female psy­
chiatric patients (Horsman 1970). More frequent sick-leave is also
reported among alcoholics (Pell 1970, Berglin 1974). In two studies of
female alcoholics (Medhus 1974, Dahlgren 1979) the disability rate
increased markedly in the years before registration by the Temperan­
ce Board or in the years after the first treatment period in a psy­
chiatric department for alcoholism. It has also been observed that
alcoholics are treated more often for psychiatric complaints and musculo-skeletal complaints like low-back-pains (Westrin 1973, Larsson
1976). As Dahlgren (1981) has pointed out there have been secular
26
changes in female alcohol consumption. Women born during the 20's
and 30!s had a late onset of diagnosed alcoholism, and the latencytime from the regular use of alcohol to the onset of alcoholism was 24
years. Women born during the 40's became alcoholics much earlier and
their course was more fulminant being accompanied by psychiatric
disorders, social problems and somatic complications. The latency
times from regular use of alcohol to alcoholism was very short, about
5 years.
Criminals, who also have a higher rate of substance abuse, have a
greater morbidity according to sick-insurance cards (Johansson 1981).
Repeated sick-leave (Ferguson 1972) has been associated with neuro­
sis, alimentary, upper respiratory tract disorders and injury. Re­
peated short-term sick-leave was associated with an increased fre­
quency of psycho-social disturbances (Leijon 1982).
27
MATERIALS AND METHODS
The cohort of adoptees
The cohort consists of all persons born out of wedlock in Stockholm
during the years 1917-1949, who were placed in non-related adoptive
homes, i.e. 2 966 adoptees, 1 354 males and 1 612 females. 751 were
born during the period 1917-1929 and 2 215 were born 1930-1949.
Most of the adoptees (58 %) were placed in adoptive homes during
their first year of life and 26 % were placed during their second
year. A further 9 % were placed before the age of 3 years. Finally
7 % after 3 years of age (placement-age is not synonymous with age
at which the adoption gained legal force). The mean age of placement
for the adoptees born 1917-1929 was 1.5 years and the mean age of
placement for those born 1930-1949 was 12 months. The adoptees
placed after the age of 3, however, were excluded from the analyses.
In Paper I the cohort consisted of 2 323 persons, but it was later
discovered that some of the adoptees had been placed with relatives.
494 (16.7 %) biological fathers have not been identified in this cohort.
This was quite a wide variation in the type of care before placement
in the adoptive home: 10.7 % were placed directly in the adoptive
home from maternity hospital; 47.2 % were cared for by the biological
mother only before placement; 5.9 % were in institutions only; 23.8 %
were cared for both by the biological mother and in an institution and
12.3 % were cared for by the biological mother, in an institution and
in a foster home. Sometimes the child was temporarily in care in
different institutions or foster homes. 10.6 % had experienced 4 or
more temporary placements - the highest number being 18.
Children born out of wedlock were chosen because at that time every
child who was born of an unmarried mother was appointed a Child
Welfare Officer and the case was recorded by the Child Welfare Of­
fice. A record was also kept of cancellations of the appointment and
the reason for it, e.g. if the mother married the father of the child
or if the child was placed in an adoptive home and legally adopted.
28
Register data
Data about the adoptees and their biological and adoptive background
were obtained from:
a)
Official records such as the criminal register and the Temperance
Board register. These contain information about criminal ver­
dicts, registrations of offences against the Temperance Act,
treatment in institutions for alcoholics and supervision because of
alcohol abuse.
b)
Records kept by the adoption agency and the Child Welfare
Office. These contain information about preplacement history,
age of the adoptee at placement, age, residence and occupational
status of the adoptive parents at the time of placement.
c)
Records kept by the National Health Insurance Offices - the
Insurance-cards (Försäkringskort or so-called F-cards). These
contain information about sick-leave periods, diagnoses or symp­
toms. Information about hospital-care is also registered, but this
kind of information is not completely accurate. Until the end of
1973 the chief complaint or diagnosis for each period of sickleave was recorded manually. From 1974 these records were
computerized and the diagnoses were no longer noted.
Firstly the F-cards for 2 118 adoptees born 1930-1949 were
collected and were used for further studies of sick-leave pat­
terns .
1 677 adoptees remained for the study of sick-leave patterns
after exclusions on the grounds of late placement, uncertain
paternity, emigration, early death or missing data. Each sickness-occasion was assigned one of 18 categories according to the
chief complaint or the diagnosis if certified by a physician. The
categories are: 1) Headache, 2) Pneumonia, 3) Astma, 4) Upper
Respiratory Infections, 5) Cardiac Disorders, 6) Peptic Ulcer
29
Disease, 7) Liver and Gallbladder Disorders, 8) Dyspepsia, that
is other trancient gastrointestinal complaints, 9) Uro-genital
Disorders, 10) Backache, 11) Other Joint Pains, 12) Anemia, 13)
Asthenia, that is non-specific complaints of fatigue or weakness,
14) Psychiatric Disability, 15) Pregnancy Complications, 16)
Accidents occurring at Work, 17) Out-of-Work Accidents, 18)
Other complaints or disorders.
The F-cards for 649 adoptees born 1917-1929 were also collected,
but these were not used in the sick-leave study because these
persons were quite old when the national insurance system
started (27 to 39 years old). These F-cards were only analyzed
manually to discover the adoptees with psychiatric disabilities.
An F-card was selected for a non-adopted control from the same
local Insurance Office. The control was matched pair-wise for
sex, age and residential area. Thus the non-adopted control may
be regarded as a fairly representative sample of a Swedish adult
population. There was good agreement between adopted probands
and non-adopted controls concerning occupational status, accord­
ing to a modified British classification (H.S.M.O., London 1951).
As the chief complaints and diagnoses were not recorded after
1973 only the period 1955-1973 was considered for the sake of
uniformity and completeness.
Records concerning adopted and non-adopted persons from
psychiatric departments and mental hospitals all over Sweden. If
the person had been on sick-leave for at least two weeks with a
pscyhiatric diagnosis (no. 290-309 ICD-8) a record was sought
from psychiatric hospitals and departments. The National Health
Board has a register of in-patient treatment in psychiatric de­
partments and psychiatric hospitals. This register was started in
1972 but it was used when searched for the adoptees and their
parents involved in the depression-study. In this way some more
records were found, mostly however persons already identified as
ill. In all, 218 adoptees with a record were discovered.
30
Psychiatric diagnoses were made from these records using the
following criteria: 1) Schizofrenie syndrome (Feighner criteria),
2) Other non-affective psychoses, 3) Non-affective neuroses
(Feighner criteria), 4) Personality disorders (Feighner criteria
1972), 5) Organic cerebral syndrome verified by X-ray or EEG,
6) Abuse of alcohol or drugs defined as (i) at least one year of
regular abuse, (ii) the substance abuse was the major problem
for the patient or society, (iii) criteria of Feighner for probable
abuse were fulfilled, 7) Unipolar affective disorder (C. Perris
criteria 1966), 8) Bipolar affective disorder (C. Perris criteria
1966), 9) Cycloid psychosis (C. Perris criteria 1974), 10) De­
pressive syndrome NUD (Major depression according to DSM-III),
11) Neurotic reactive depression (d'Elia criteria 1974), 12) Un­
classified .
Reliability of psychiatric diagnoses
Initially 96 randomly selected records concerning both adopted and
non-adopted persons were evaluated by 4 independent, trained psy­
chiatrists (C. Perris, L. von Knorring, M. Bohman, A-L. von Knorring). The above-mentioned diagnostic categories were used. As the
different diagnoses were not similarly weighted all the different affec­
tive disorder diagnoses were put together. Schizofrenie syndrome and
other non-affective psychosis were also put together. There were 7
diagnostic groups to consider for the reliability-test. Totally all four
psychiatrists agreed about the diagnosis in 61.5 % of cases (from the
classifiable records they agreed in 72 % of cases) and three of four
agreed in 77 % (in 88 % for the classifiable records). The best agree­
ment was for alcohol and drug abuse all four raters agreed about 81 %
of these cases.
In the depression study firstly 62 records concerning adopted persons
were selected. In this sample all the above-mentioned diagnostic
categories were taken into account for reliability calculations. All four
raters diagnosed the records independently, 56 persons remained in
the affective disorder group and 59 persons were assigned to the
31
substance abuse group. For the affective cases the rates of agreement
amongst the psychiatrists were as follow: all four in agreement 33.9 %
(19 out of 56 cases); at least 3 out of 4 in agreement 62.5 %; at least
2 out of 4 in agreement 85.7 %. The final diagnoses were made after
consensus.
The parents' records were blindly rated by two of the psychiatrists
(A-L. von Knorring and L. von Knorring). Here there was an 80 %
agreement about the diagnoses (k = 0.64, Z = 12.8 p < 0.001). For
alcohol abuse there was 100 % agreement. Not all the adoptees with a
diagnosis of alcohol and/or substance abuse in their psychiatric
records were included in the Temperance Board register. Only 29 % of
the females and 58 % of the males had one or more registrations.
No of registrations with the Temperance Board
Males
Females
0
1-4
>4
0
1-4
Psychiatric diagnosis
of alcohol abuse and/
or drug abuse
males N = 38
females N = 21
16
5
17
15
6
(42%)
(13%)
(45%)
(71%)
(29%)
-
Psychiatric diagnosis
of primary affective
disorder and secondary
alcohol abuse
males N = 4
females N = 4
3
1
-
3
1
-
(75%)
(25%)
-
(75%)
(25%)
-
Psychiatric diagnosis
of affective disorder
only
males N = 6
females N = 42
4
2
-
40
2
-
(67%)
(33%)
-
(95%)
(5%)
Table 1.
>4
Cross-tabulation of Temperance Board registration and psy­
chiatric registration of alcohol abuse.
32
In this group of 59 adoptees with a psychiatric diagnosis of substance
abuse 8-4 men and 4 women - had died of complications due to
alcoholism (such as cirrhosis of the liver, brain injuries or acute
intoxication). Only two of these men and one woman appeared in the
Temperance Board records.
Life events
Life events precipitating a depressive episode were rated from the
medical records. It was assumed that stressful events were reported
in the records. Most of these records contain a satisfactory amount of
information. The explicit criteria described by Pollitt (1972), H.
Perris (1982) and Samuelsson (1982) were used. Only undesirable,
external ("independent") events occurring within 3 months of onset of
the first depressive symptoms in a treated episode were accepted.
The specific events are both somatic (e.g. surgery) and psychosocial
(e.g. parental death, divorce) (see Appendix I).
Statistical analyses
Chi-square tests with Yates' correction were used to evaluate differen­
ces between frequency distributions. Pearson's was used to test
hypotheses of a correlation (Colton 1974). In Study No VI the propor­
tion of parents with psychiatric disorders was computed in terms of
life-time risks. No age adjustment was required because tests were
carried out comparing age-matched controls. Comparisons of the
proportion of sick parents in the matched pairs were made using
McNemar's chi-square (Cloninger 1979a).
Several series of discriminant function analyses were carried out with
the help of SPSS programmes (Nie 1975). For more detailed informa­
tion see the separate papers Nos II, III, IV. Discriminant function
analyses were used to predict psychiatric disorders on the basis of
the placement variables and to identify sick-leave variables that
distinguish subgroups of adoptees from one another.
33
Admixture analyses was used to analyse the distribution of a discri­
minant function derived to distinguish subgroups in a larger popula­
tion e.g. as in this study to distinguish female somatizers from other
women. If means differ widely even small subgroups can be detected
in samples of a practical size. The admixture analysis was carried out
using the Fortran program SKUMIX (MacLean 1976). For further
information see Paper No IV.
To analyse the effects of the various combinations of categorial back­
ground classifications (congenital and postnatal) on the observed
personal status FUNCAT analysis using linear logistic models was
carried out (Helwig 1979). For further information see Paper No V.
34
RESULTS
Psychiatric illness among adoptees (Papers I and III)
A higher frequency of psychiatric illness, defined as being on sickleave for more than 2 weeks with a psychiatric diagnosis, was found
among the adoptees than in matched non-adopted controls (see Paper
I Table 2). The number was greater for the adopted females than for
the adopted males. The adopted women also had more frequent and
longer periods of psychiatric sicke-leave (see Paper III Table 1). For
the adopted men, however, the frequency of sick-leave due to psy­
chiatric complaints was no greater, but there was a tendency for it to
last longer (see Paper III Table 3).
It was found from psychiatric records that the over-representation in
the male group was due to substance abuse, personality disorders and
neurotic disorders. For the female group there was also an overrepresentation of substance abuse and personality disorders (see
Paper I Table 3). The number of adopted women who had been on
sick-leave due to psychiatric complaints but had no hospital records
from psychiatric facilities (see Paper I Table 4) was significantly
larger than that for non-adopted controls.
Somatic illness among adoptees (Paper III)
The adopted women had an increased frequency of physical com­
plaints, but they had no increased duration (see Paper III Table 1).
The non-adopted controls had fewer sick-leave periods but these
occasions tended to be longer in duration. In contrast the adopted
women more often had brief but frequent sick-leaves each year. More
female adoptees than controls had 2 or more sick-leave periods per
year (16.8 % versus 11.5 %). The overall excess of sick-leave amongst
female adoptees was mostly due to complaints for transient problems
that did not require medical certification i.e. sick-leave lasting less
than 7 days (see Paper III Table 2). Upper respiratory infections and
abdominal complaints were more common reasons for sick-leave among
35
adoptees than non-adoptees. The adopted women had more than three
times as many children as age-matched non-adopted controls, so they
had more sick-leave for pregnancy complications per year, but not
per child.
The adopted men did not have any excess of sick-leave complaints nor
were there any differences within individual categories of somatic
complaints (see Paper III Table 3).
The relation of somatic and psychiatric illness (Papers III and IV)
Among the 859 adopted women 27.4 % and among the 818 adopted men
17.7 % had one or more periods of sick-leave, the chief complaint or
diagnosis being psychiatric. Adoptees with and without psychiatric
disability were compared as regards the pattern of somatic sick-leave.
Possible predictors of psychiatric disability were frequency and dura­
tion in each of the 16 specific somatic categories and the overall
measures of somatic frequency, duration and diversity (the ratio of
the number of categories to the total number of occasions). Another
variable for somatic frequency was whether or not the subject was a
somatizer (having 2 or more occasions of sick-leave due to somatic
complaints per year). The significant discriminating somatic variables
can be seen in Paper III Table 4 (for women) and Paper III Table 5
(for men). Limited diversity of complaints, long duration of abdominal
and upper respiratory and urogenital complaints, high frequency of
accidents outside work and complaints of fatigue and weakness were
associated with psychiatric disability in both men and women. The 11
variables (shown in Paper III Table 4) accounted for 20.32 % of the
variability in risks for psychiatric disability in women, and the 16
variables (in Paper III Table 5) accounted for 22.8 % of the variance
in psychiatric disability in men. Being a somatizer accounted for more
than half of the explained variance in women and about one-third of
the explained variance in men. Overall 36.2 % of adopted women with
psychiatric registrations were somatizers compared to 9.5 % of other
adopted women. 141 (16.4 %) adopted women were either registered or
predicted from the statistical analysis to have psychiatric disability.
36
The incidence of somatizers among women with registered psychiatric
disability was 36 % while the incidence in women with predicted or
registered psychiatric disability was 59.6 %. The incidence of somati­
zers in women with no registered or predicted psychiatric disability
was 0.4 % (see Paper III Table 6). In other words 98.6 % of the
somatizers were either registered for psychiatric disability (59.0 %) or
were predicted to have psychiatric disability (39.6 %).
In average somatizers were 1.67 years younger than the others. This
difference accounted for less than 2 % of the variability in risk for
somatizers although it was significant. The variables shown in Paper
III Table 7 were used as predictors in a discriminant analysis to
distinguish the adopted somatizers from the non-adopted women.
These variables were then used as predictors in another discriminant
analysis to distinguish the adopted somatizers from other adopted
women (see Paper III Table 8).
The 859 adopted women were split into 2 samples by stratified random
sampling of the 144 somatizers and 715 others. A discriminant function
was derived to distinguish between somatizers and non-somatizers in
one sample (the criterion sample), and was applied to the other
sample (the replication sample). This function accounted for 68 % of
the variability in the somatizer status. The criterion sample had
98.8 % accuracy of classification and the replication sample had 97.4 %
accuracy of classification (see Paper III Table 9). In particular a high
frequency of disability from complaints in the head, back and the
abdomen were associated with somatizer status (see Paper III Fig. 1).
The distribution of the discriminant function scores for somatization in
both the criterion sample and the replication sample suggests that
both the samples were trimodal, with one antimode separating the
somatizers and non-somatizers and a second antimode separating the
somatizers into 2 groups (see Paper IV Fig. 2). Admixture analysis of
the distribution scores in the replication sample showed that the two
components accounted for the observed distribution much better than
did one distribution, and furthermore three components described the
37
data better than two did (see Paper IV Table 1). Skewness was
significant regardless of whether the number of distributions was one,
two or three. The extreme group of somatizers (type 1) did not
overlap at all with non-somatizers. The intermediate component (type
2) overlapped slightly with each extreme group (see Paper IV Fig. 1
and Table III). Type 1 somatizers had a high total frequency but
limited diversity of complaints and their sick-leaves were consistently
for abdominal and back problems. Type 2 somatizers took sick-leave
less often but for more diverse complaints (see Paper IV Fig. 3).
Type 1 somatizers had the highest occurrence of psychiatric com­
plaints whereas type 2 somatizers had the lowest rate of psychiatric
disability relative to total frequency of sick-leave (see Paper IV Table
4). Backache was an infrequent complaint for type 2 and common for
type 1. The frequency and duration of abdominal problems were
greater in type 1 somatizers (see Paper IV Table 2).
Divorce and low occupational status were more common in both types
of somatizers and they had more pregnancy complications per child.
They had fewer children than others, age into account (see Paper IV
Tables 4 and 5). Type 2 somatizers were intermediate to the other
groups for all the social and demographic characteristics measured.
Somatization was also associated with alcohol abuse and criminality
(Paper IV Table 6). 29.7 % of type 1 and 10.8 % of type 2 somatizers
had been registered for alcohol abuse and/or criminality compared to
2.6 % of other adopted women.
Early childhood experiences and psychiatric disorders (Paper II)
Psychiatric illness amongst adoptees, defined as in- or out-patient
treatment at a psychiatric department, had no specific association with
any special kind of preplacement care before adoption. Nor was there
any association between length of care and psychiatric illness. A
higher divorce rate was found among the adoptees who had been in
care in institutions only.
38
There was no linear relationship between age at placement in an
adoptive home and the incidence of psychiatric disorder i.e. psy­
chiatric disorders were no more frequent among those who were
placed late. Concerning the hypothesis of critical periods the cohort
was classified into four subgroups according to age at placement 1)
0-5 months 2) 6-11 months 3) 12-17 months 4) 18 months or later.
There was only a slight increase in the number of psychiatric dis­
orders among those placed at 6-17 months. Those adoptees with a
diagnosis of reactive-neurotic depression were placed at the age of
6-11 months inc. significantly more frequently than expected (see
Paper II Fig. 1).
There was no correlation between length of institutional care and
psychiatric disorders, or number of placements before adoption.
Series of multivariate analyses in order to predict psychiatric dis­
orders from early life experiences showed that the inter-groups
(psychiatric illness or not) differences were small compared to intragroup variance. Thus there was a considerable overlap between the
groups.
Postnatal childhood experiences and somatization {Paper V)
Postnatal variables that distinguished both groups of somatizers and
the non-somatizers were occupational status of the adoptive father,
age at placement, contact with biological mother lasting more than 6
months and alcohol abuse by the adoptive father (see Paper V Table
4) but these 4 variables only weakly distinguished the 3 groups.
Alcohol abuse by the adoptive father was relatively common among
type 2 somatizers.
Environmental influences on affective disorder and substance abuse
(Paper VI)
The risk of psychiatric illness was greater in the adoptive parents of
the cases with affective disorders and substance abuse compared to
controls, but the difference was not statistically significant. When
39
parents were divided according to sex it was found that the excess
was due to a higher frequency of psychiatric illness among adoptive
fathers. (8.7 % versus 1.7 % b/c = 9/1 p = 0.01) (see Paper VI Table
4). Both males and females with affective disorders or substance
abuse had an excess of sick adoptive fathers. There was no diag­
nostic concordance in the parent-child pairs (see Paper VI Table 6).
The excess of sick adoptive fathers was almost entirely due to affec­
tive disorders. The temporal sequence of illness was evaluated in the
7 families in which the adoptive father was treated for affective dis­
order and the adoptee was treated for substance abuse or depression,
4 of the 7 adoptees were treated before their parents were treated, 1
was treated the same year and 2 were treated afterwards.
Genetic inheritance of affective disorders and substance abuse
(Paper VI)
The lifetime risk of psychiatric illness was almost the same in the
biological parents of the cases with affective disorders and substance
abuse as in their matched controls. Female cases had sick biological
mothers more often than did their matched controls, but if the pro­
bability of this difference was conservatively adjusted for the number
of tests the excess of the sick biological mothers was marginally
significant or at least a trend (p < 4 x 0.015 = 0.06). Other differen­
ces in the biological parents were clearly insignificant (see Paper VI
Table 3). There was no evidence of familial aggregation of biological
parents and adoptees with the same diagnosis (see Paper VI Table 5).
The excess of illness in biological mothers of female cases was not due
to over-representation of any specific diagnostic category. The largest
contribution was that due to an excess of substance abuse amongst
the biological mothers of adoptees with affective disorders compared to
the mothers of adoptees with no disorders (7.1 % versus 0.9 % p <
0.025) but this was not individually significant after correction for
multiple tests. The possibility of etiological heterogeneity among the
different subtypes of affective disorders was evaluated (see Paper VI
Table 7). There was no significant heterogeneity among the biological
parents of psychotic and non-psychotic depressives. There were
40
sufficent cases for the statistical calculations of non-psychotic de­
pression (N = 40) and psychotic depression (N = 11) but not for
bipolar or cycloid psychoses (N = 5).
Genetic inheritance of somatization disorder (Paper V)
The genetic background was classified by a discriminant analysis of
an independent sample of biological parents of adopted men, as in
earlier reports. The genetic background was divided into the 5 cate­
gories that were most characteristic of men with type 1 (mild or
severe) alcoholism, type 2 (moderate) alcoholism, petty criminality
only or neither alcohol abuse nor criminality (low risk). There was a
significant excess of type 2 somatizers amongst women with a genetic
predisposition the same as that characteristic of men with petty crimi­
nality, compared to daughters at low risk (see Paper V Table 1).
There was also an excess of type 2 daughters with a genetic pre­
disposition to type 2 (male limited) alcoholism compared to low risk
daughters and to daughters with a type 1 (milieau limited) alcoholic
background. The daughters with the same background as male limited
alcoholism had an excess of type 2 somatization (see Paper V Table
2). The daughters of petty criminals had an excess of both crime
only and type 2 somatization. Daughters with a background charac­
teristic of men with milieau limited alcohol abuse had a significant
excess of alcohol abuse themselves but no other disorders.
In order to distinguish the 2 types of somatizers and the non-somati­
zers variables concerning the biological parents were identified. The
10 variables selected were arranged in decreasing value on the second
discriminant function, which distinguished the 2 types of somatizers
(see Paper V Table 3). They accounted for 4.5 % of the variability
among the 3 groups. Somatizers were distinguished from non-somatizers by the combination of criminality, alcohol abuse and low occupa­
tional status among their biological parents. Type 1 somatizers were
distinguished from other somatizers by biological fathers with teenage
onset of non-property crimes and many registrations for untreated
alcohol abuse. Type 2 somatizers were distinguished from other soma-
41
tizers by biological fathers with property crimes and treatment for
alcoholism.
Life events related to genetic and/or social predisposition (Paper VI)
A precipitating life event occurring within 3 months prior to the onset
of depression was found in 14 of the 51 cases. A variable life event
pattern was found in another 14 cases. To test the diathesis-stress
hypothesis the adoptees were subdivided according to the presence or
absence of precipitating events and compared with the percentage of
adoptees in each group who had at least one parent ill (see Paper VI
Table 8). There were no significant differences among groups as
regards illness in either biological or adoptive parents.
Gene-environment correlation and interaction of female somatization
(Paper V)
To evaluate the extent of selective placement relevant to somatization
the extent of correlation between biological parent and post-natal
variables was tested with a stepwise discriminant analysis of the 3
groups of women. Only 1 variable of the 14 included was deleted
- the number of alcohol abuse registrations of the biological father.
Gene-environment correlation accounted only for 4 % of the variability.
The risk of type 1 somatization was determined for each of the four
combinations of developmental background generated by classification
of congenital and postnatal background into high and low risk groups
(see Paper V Fig. 1). Congenital and postnatal backgrounds were
classified independently based on the biological parent and adoptive
placement variables (see Paper V Tables 3 and 4). The pattern of
interaction between the dichotomous congenital and postnatal factors
was evaluated using a linear logistic model. Significant additive con­
tributions were made by both congenital and postnatal backgrounds,
but no non-additive gene-environment interaction was detected.
42
The interaction of congenital and postnatal factors contributing to
somatizing type 2 was evaluated (see Paper V Fig. 2). Significant
additive contributions were made by both congenital and postnatal
backgrounds. There was no significant evidence of non-additive
interaction.
A cross-fostering analysis with the three classifications (type 1, type
2 somatization and neither) was made to evaluate the full pattern of
interaction. The 9 possible combinations of congenital and postnatal
backgrounds can be seen in Paper V Table 5. Here it was possible to
reject an additive logistic model with no gene-environment interaction.
The significant interaction was mainly due to the high risk of type 2
somatizing when both congenital and postnatal backgrounds were most
characteristic of the other type of somatizing and when a woman with
type 2 congenital background was reared in an adoptive home that
was most characteristic of the other type of somatizer.
There was no significant overlap between the genetic predisposition to
type 1 and 2 somatization (see Paper V Table 6), but postnatal in­
fluences resulted in highly variable risks of type 2 somatization
regardless of genetic background. The observed risks varied about
twice as much in daughters with a low risk congenital background
(12.5 % to 22.4 %) or type 2 congenital background (21.6 % to 34.9 %)
and nearly six-fold in daughters with a type 1 congenital background
(5.0 % to 28.3 %) (see Paper V Table 5).
43
SOURCES OF ERROR
Adoption studies are a powerful tool for evaluating the environmental
influences as distinct from genetic variables. However, this method
also has its weaknesses. Most adoptees are told at an early age that
they are adopted. According to one Swedish study (Bohman 1970)
81 % of a population of adoptees were told before the age of 7 years.
This cohort of adoptees were younger (born 1955-57) than the adop­
tees in this study. Earlier the adoptive parents were not recommended
to tell their children that they were adopted. It may be assumed that
the adoptees born 1917-1949 are not so often aware of the fact that
they are adopted. There is very little information about the contact
between the adoptees and their biological parents. Bohman (1973)
found that 5 % of the adoptive parents had some personal contact with
the biological parents. In these cases the contact mostly is between
the adoptee and his family and the biological mother. Knowing about
and being in contact with the biological parents prevents the distinct
separation of the genetic and environmental backgrounds. This may
influence the results in such a way as to make the genetic factors
look more important.
However, there can also be a bias in the opposite direction as regards
psychopathological disorders. The biological parents have more social
and psychiatric problems (Bohman 1970) such as alcoholism and crimi­
nality. In a study of married mothers who had their children adopted
it was found that these mothers had significant deviation on the
clinical scales of the MMPI (Horn 1975). There was a group of women
within this group who deviated extremely. The two scales with the
highest elevation were the psychopathia and the schizofrenia scales.
This implies that there is a bias against a genetic hypothesis. There
will be a higher risk of psychopathology in the offspring, which will
reduce the differences between index and control groups especially in
studies about sociopathy (criminality) and schizofrenia. This seems to
be less important for depressions as there is no deviation on the
depression scale for mother that had their child adopted. The effect
of this bias would be particularly great when the traits of interest
44
involve the variables of age at onset, incomplete penetrance, and
polygenes. On the other hand this kind of bias is reduced by using
the adoptees' families method instead of the adoptees study method.
Adoption studies also have other limitations. The correlation of a trait
between the biological mother and the adoptee is not purely genetic.
Intrauterine factors also influence and may explain, at least to some
extent, this kind of correlation. The correlation between the biological
father and the adoptee is more probably genetic, but in this case
there are other difficulties. Blood-typing disproves paternity in about
20 % of the fathers who deny paternity of illegitimate children (Social­
styrelsen 1976). Thus the estimated number of false fathers in this
material is 20 % at the highest, and most probably much lower as the
majority of fathers in this study accepted paternity. As the biological
mothers tend to name as the father a better adjusted male if several
are possible, this kind of error will influence the results so that a
genetic hypothesis cannot be sustained. On the other hand children
of unidentified fathers do have the same adjustment as children of
identified fathers (Bohman 1980). This implies that having an un­
identified father does not bias the results.
The information in this study is based on various registers, records
etc. Swedish registers are considered unusually complete. As Rydelius
(1981) has pointed out the utilization of a register for information has
one obvious advantage, it is insensitive to any bias on the part of
the researcher. The interviewer or researcher is unable to influence
the registration. On the other hand registers also have several limita­
tions as sources of information. Temperance Board registrations
reflect social class and personality. Individuals from the lower class
run a greater risk of being registered (Bjurulf 1971). It is known
from epidemiologic studies (Öjesjö 1980) that 70 % of alcoholics are
registered either by the Temperance Board or a psychiatric depart­
ment. Non-registered alcoholics were fairly representative of the total
population of registered alcohol abusers (Kaij 1970). The information
found in the Criminal Records is probably less sensitive to variations
in social status than that in social and medical registers (Johansson
45
1981). On the other hand these data do not measure criminal beha­
viour that is not known to society.
Hospital registers have been thought to be less sensitive to social
factors. Smedby (1974) considered after comprehensive empirical
research that the state of health of an individual determines whether
he becomes a heavy user of medical care. E. Johansson (1981) has
worked with the information from National Insurance Cards concerning
criminals and has concluded that it is not possible to measure the
"purely medical" but rather the social aspects of illness. To a varying
degree this is true also in cases of hospitalization, apart from a few
instances with absolute indications.
Personality also influences the illness behaviour. Bond & Pearson
(1969) found that personality not only influenced the experience of
pain but it also influenced the ability to communicate about pain.
Information from hospital records may have some disadvantages. The
quality of information varies, but some basic information is available.
According to a reliability study (Hostetter 1983) full medical records
and interview schedules showed a high concordance of diagnosis.
There are also some advantages in using information from records:
the patient himself may have difficulty in remembering retrospectively
and is more likely to provide false information. Data about life events
may not be consistently reported in the records but negative and
severe life events are supposed to be reported to a greater extent.
In this case the bias is not in any specific direction.
Hospital records about parents were found less often than expected
from epidemiological data. One explanation is that we only searched
the records of psychiatric departments and hospitals and thus missed
any information given when the parent consulted a general practi­
tioner or a private doctor. However, the number of cases missed for
this reason is likely to be the same for both proband and control
group. The differences found thus seem reliable.
46
DISCUSSION
Somatic complaints and psychopathology
It was hypothesized that adopted persons are overall more vulnerable
to psychiatric illness and somatic complaints than the general popula­
tion. The results in this study support the hypothesis. This is in
line with the results of earlier research which has found that the
outcome of adoption is good on the whole, but that the risk of mal­
adjustment is greater.
There was a higher incidence of alcohol abuse and personality dis­
orders among both adopted men and women but the former also had
higher incidence of neurosis which the latter did not. There was no
överrepresentation of affective disorders in either sex. Female adop­
tees with psychiatric disability saw a psychiatrist less often than both
male adoptees and controls. It is conceivable that they consulted a
general practitioner instead.
Adopted women had an increased frequency of somatic complaints, but
adopted men did not. The adopted women had an excess of sick-leave
mostly due to transient complaints lasting less than 7 days, mainly
upper respiratory infections and abdominal complaints.
Further analyses were carried out in order to discover any special
patterns of sick-leave. Somatic sick-leave on more than 2 occasions
per year was correlated to psychiatric complaints. The group of
persons who had this kind of sick-leave pattern were called somatizers, because of the correlation to psychiatric disability. There were
fewer male somatizers than female. The observation time in this study
lasted 8-18 years and therefore the somatizers had at least totally 16
sick-leaves. At this point it is not possible to define for how long
time of observation is needed in clinical work for a classification of
this syndrome from similar patterns of sick-leave. Female somatizers
were younger than non-somatizers, which may reflect an association
with alcohol abuse.
47
During the last few decades (Dahlgren 1981) women have started to
drink at a much younger age than in earlier generations. Adopted
women had an excess of somatization compared to non-adopted con­
trols. The sick-leaves were mostly because of backache and abdominal
distress. The symptoms were often self-limited and transient, but
abdominal disorder and psychiatric disability were of longer duration.
The somatizers could be divided into two separate types, which differ­
ed both as regards the extent of their disability and the pattern of
their psychatric and somatic complaints.
Type 1 (high frequency) somatizers had very frequent sick-leaves
with psychiatric, abdominal and back complaints. They also had a
high frequency of registrations for alcoholism (19 %) and crime (10 %),
10 times greater than that for non-somâtizers. It has been observed
that alcoholics have an excess of medical treatment for psychiatric
disability and musculoskeletal disabilities like low-back ailments (Dahl­
gren 1979, Medhus 1974, Larsson 1976, Westrin 1973). It would be
useful to know how often somatization precedes alcohol abuse and vice
versa.
Type 2 (diversiform) somatizers were more common than type 1 and
had more diverse somatic complaints in general, and a lower propor­
tion of all their sick-leaves involved chiefly psychiatric complaints or
backache. Alcohol abuse and criminality were not as common as among
type 1 somatizers, although they were four times more frequent than
among non-somatizers.
Somatization of both types was associated with a high divorce rate,
low occupational status and youth. Similar observations have been
made by others (Leijon 1982). One explanation for the youth of the
somatizers may be the secular trend of female alcoholics in Sweden.
Younger female alcoholics have a more fulminant course with more
medical and social complications than older female alcoholics (Dahlgren
1981). On the other hand patients with psychiatric disorders have
more somatic symptoms when younger (Guze 1972).
48
The somatizers identified in this study bear some similarities to pa­
tients suffering from clinical psychiatric syndromes described earlier.
Over 150 years ago Benjamin Rush (1812) described hypochondriasis
as follows: "The symptoms of this form of dearangement as they
appear in the body are dyspepsia, congestiveness or diarrhoea...,
strong venerai desires or absence of venerai desires, pains in the
limbs..., a disposition to faint, wakefulness, indisposition to rise out
of bed...". According to DSM III patients with hypochondriasis are
preoccupied with different somatic signs and are convinced they have
a serious disease. However little is known about the illness beha­
viour, i.e. whether or not they consult a physician or if they turn to
friends with their problems. Hypocondriasis is considered to be a
chronic state (Kenyon 1964). Briquet's syndrome or somatization
disorder according to DSM-III is also similar to the symptoms ex­
hibited by the group of somatizers in this study. It is characterized
by abdominal distress, back-pain and psychiatric disability combined
with a chronic course. Somatizing could also be a manifestation of
masked depression which according to Lopez Ibor (1969) is phasic in
its course. The courses of "endogenous" depression (Nyström 1979a)
and neurotic depression (d'Elia 1974) are similar in some respects to
the course found for somatizers - transient, self-limited and recurrent
over several years.
It is not possible however to draw any definite conclusions about the
relationship between clincially defined syndromes and the more common
groups of somatizers, defined according to epidemiological sick-leave
register data. Therefore it would be necessary to study the group of
somatizers clinically in order to obtain a more detailed description of
their somatic and psychiatric status.
Environmental influences and psychiatric disability
Early negative experiences such as bereavement are found to increase
the risk of psychatric illness later in life (Brown 1966, d'Elia 1971).
Our contention was that institutional care during infancy, or unstable
placement procedures were such negative experiences. It has been
49
suggested that 6-12 months is a critical age both as concerns the
effect of separation (Spitz 1945, Schaffer 1968) and the establishment
of social relationships. Disturbances during this critical period are
supposed to increase risk of depression and divorce.
Placement variables did not explain the manifestation of psychatric
disorders in general or the divorce rate. This is in line with the
findings of an earlier study of adoptees where placement variables did
not explain maladjustment or underachievement while in school (Boh­
man 1979).
However, reactive neurotic depression was significantly correlated
with placement at the age of 6-12 months. This could be a a chance
effect. However a closer analysis showed that most cases (7 out of
10) in the reactive neurotic group who were placed at the age 6-12
months had been cared for by their biological mother or a foster
mother until placement in the adoptive home. Thus there is some
support - but weak - for the hypothesis that separation at the age of
6-12 months will affect later development.
Early object loss plays a central role in psychoanalytic theories con­
cerning the origin of depression. It has been assumed that the ori­
ginal trauma, which is caused by object-loss in early childhood, can
be reactivated later by new losses (Mendelsson 1974). Our findings
provide some support for this theory. The adoptees with reactive
neurotic depression had the highest rate of divorce (57 % of those
ever married) and thus have experienced object-losses. The evidence
however is not convincing because there is only a weak statistical
significance.
Earlier research on the influence of psychiatric illness in parents
focused very much on the mother's influence on the child. However,
in recent years interest in the father has increased (Earles 1976). A
few studies have been carried out which have found that the father's
mental health influences on the attitudes and treatment-seeking be­
haviour of the children, especially the sons (Rydelius 1981, Nettel-
50
bladt 1981). In line with these studies, we found that children whose
adoptive fathers had affective disorders were more likely than other
adoptees to seek psychiatric treatment themselves as adults. This
non-genetic influence occurred regardless of the sex or diagnosis of
the adoptee, but is strongest in adopted sons with substance abuse.
Our data also suggest that the children did not simply imitate the
illness of their adoptive parents because the children were often
treated earlier than were their parents. Onset may depend on other
variables such as feelings of self-insufficiency and attitudes about
seeking help from psychiatrists. It has been suggested that cognitive
styles of self-assessment may be learned in childhood and influence
later self-esteem, self-reliance, non-specific vulnerability to stress
etc. (Beck 1967, Raps 1982, Valliant 1982, Coopersmith 1967). Since
such characteristics seem to be acquired at an early age parents have
been vulnerable longer than their children and would seek treatment
before their children. Adoptive parents are, however, selected for
their ability to provide a stable environment for their children. There­
fore most potential parents with an early onset of psychiatric dis­
ability were not permitted to adopt children. Our data support the
idea that the home environment, and not only imitation, is important
as a determinant for disability and treatment for both depressive
disorders and substance abuse. This has also been found in other
studies (Brown 1978, Shepherd 1966).
Low social status of the adoptive father was one environmental factor
which increased the risk for both types of somatization. Type 2
somatizers also had had longer contact with their biological mothers
before placement in adoptive homes and alcohol abuse was more common
in their adoptive fathers. Early separation from the biological mother
and early placement was more characteristic for the type 1 somatizers.
The lower classes are reported to have a higher frequency of joint
and back-problems (Carlsson 1979), and low social status is also
related to an increased frequency of psychiatric and somatic illness
(Jonsson 1967). Absenteeism, especially for short-term illness, is
51
highest among manual workers with a low income (Eriksen 1980). Our
finding that somatizers had a lower status agrees with these earlier
studies. Among the general population 60 % have the same social
status as their parents (Jonsson 1964), the figure is even higher for
the lowest group. The correlation to the low social group of the
adoptive fathers may be the same as the correlation found in the
general population. It is not possible to draw any conclusions from
this study about whether this association to low social status between
the adoptee and the adoptive father is environmental. Cross-fostering
studies would be required for elucidation of this point.
Genetic influences on psychopathology
The female cases with depression and substance abuse more often
than controls had biological mothers who had a psychiatric diagnosis
although the figure was not statistically significant after corrections
for multiple tests. Similarily other studies have observed a higher
concordance in mother-daughter pairs than in other parent-child
relationships (Stenstedt 1952, Smeraldi 1979). However, although
there was a correlation concerning psychiatric illness in general, we
observed no increased concordance between the adoptees and their
parents for the same diagnosis. Genetic factors therefore exert only
weak and non-specific influences on vulnerability to depression and
substance abuse. This is similar to the findings for non-psychotic
depressions in intact Swedish families (Perris C. 1982) and Danish
twins with non-endogenous depression (Shapiro 1970).
There was no genetic overlap between affective disorders and sub­
stance abuse. This is in line with the study of daughters of alcoholic
fathers where no excess of depression was found unless they were
raised by the father (Goodwin 1977). On the other hand substance
abuse and other non-affective disorders accounted for most of the
excess of psychiatric illness in the mothers of affective disorder
patients. A study of the relationship of untreated alcohol abuse in
biological parents to depressive disorders in children would provide a
more thorough means of testing of the hypothesis that alcoholism and
52
depression share a common genetic basis in some families. At present
however our results, together with Goodwin's findings, suggest that
cultural inheritance is the major determinant in any familial aggre­
gation of depression with alcoholism. This casts doubt on Winokur's
"depressive spectrum" hypothesis, that depression and alcohol abuse
are simply sex-modified expressions of the same genotype in some
families.
We did not find any evidence to support the theory that psychotic
and non-psychotic depressions are genetically distinct. None of the
biological parents of psychotic depressives and none of the biological
parents of bipolar cases had an affective psychosis. This is consistent
with the discussion of Lewis (1938) and Kendell (1976) that there is
no 'point of rarity' between psychotic and neurotic depressions.
Akiskal (1978) in his follow-up of neurotic depressions found that this
group was heterogenous. In this study we have used a multicategory
classification based mainly on ICD-9. Patients with reactive neurotic
depression according to our definition consisted of a heterogeneous
group some of whom had an environmental precipitant and others a
personality trait of general nervousness without any clear, severe
precipitant other than a "break-down".
Reactive depressions are more common in younger people while the
"endogenous" depressions increase with age, being most common over
50 (Post 1968). As the majority of our adoptees are below 50 we can
assume that if we repeat the same study in 10 years time we will find
more "endogenous" or "psychotic" depressions in the material.
Our results contrast to the findings of Mendlewicz (1977) who found a
genetic correlation between 29 bipolar adoptees and their biological
relatives in Belgium. Our cases consisted mostly of non-psychotic
depressives which may explain the differing results. Our data indicate
that there may be a minimal, genetic contribution to the familial
aggregation of individuals with a specific diagnosis of primary major
depression. The familial aggregation observed in earlier studies of
major depression was probably due largely to sociocultural effects.
53
Our earlier findings on the inheritance of alcohol abuse indicated that
the genetic influence on some forms of alcoholism (milieau limited) was
weaker than on other forms (male limited) of alcohol abuse (Cloninger
1982). This may also be the case for depressive disorders. Support
for this is also found in genetic research about personality traits as
they are differentially heritable (Zuckerman 1979, Loehlin 1982).
According to our hypothesis somatization as shown in this study is
genetically correlated to alcohol abuse and criminality. Four familial
patterns have been distinguished. In one group of families the men
are often petty criminals, but they seldom abuse alcohol, and the
women are type 2 somatizers and/or petty criminals. In the second
group of families the women are type 2 somatizers but they themselves
are neither alcoholics nor criminals. Their male relatives often have
type 2 alcoholism (male limited type) which can be associated with
criminality, but seldom have criminal behaviour in the absence of
alcohol abuse. In the third group of families the women are type 1
somatizers and their male relatives have a teenage onset of criminality
with frequent registrations by the Temperance Board, but infrequent
convictions for property crimes. About 30 % of the type 1 somatizers
were also registered for alcohol abuse or criminal behaviour. As
female alcoholism is more difficult to detect the frequency of alco­
holism may be much higher, which indicates that the majority of type
1 somatizers are alcohol abusers. In the fourth group of families there
was no excess of criminality or somatization, but men and women are
at a high risk level for type 1 alcohol abuse (milieau limited). These
findings are comparable with those of some earlier studies of somato­
form disorders (Arconac 1963, Cloninger 1975, 1978) and imply that at
least some of the somatizers would fit into this from clinical materials
defined Briquet's syndrome.
Gene-environment interaction on psychopathology
According to the diathesis-stress hypothesis a greater genetic and/or
social predisposition is required for the onset of depression without a
precipitating life event. To test this hypothesis we subdivided the
54
adoptees according to the presence of precipitating events within 3
months prior the onset of depression and compared the percentage of
adoptees in each group who had at least one parent ill. The rating of
the life events was made from the information in the records using
the criteria of Pollitt, H. Perris and Samuelsson. There were no
significant differences among the groups as regards illness in either
biological or adoptive parents. This is quite contradictory to the
results of Pollitt (1972), but is in line with the findings of H. Perris
(1982b). Our findings imply that "stressful" life events in adult life
do not contribute to the genetic and social liability to depressive
disorders. This casts doubt on the relevance of comparing clinical
depressive disorders with untreated dysphoria in the general popu­
lation. Judgements about the severity of putative stressors made by
non-patient populations may be irrelevant to their presumed effect as
précipitants of pathological depressive episodes. The coincidental
occurrence of stressfull events may act as the non-specific triggers in
the onset of illness. Genetic factors and childhood environment play a
permissive role that is not modified by adult events. Later stressors
may possibly determine onset at a specific time.
Both genetic and environmental factors predispose a subject to soma­
toform disorders. The same genetic factors that predispose both men
and women to petty criminality are also expressed as type 2 somati­
zation in women.. An unskilled occupational status on the part of the
adoptive father is also associated with an increased risk of both petty
criminality amongst men and type 2 somatization amongst women.
Alcohol abuse in adoptive father is associated with an increased risk
of type 2 but not type 1 somatization. Low social status had a differ­
ent pattern of interaction with the 2 types of genetic predisposition.
The environmental factors that were most characteristic of type 2
somatizers (contact with biological mother and adoptive father's alcohol
abuse) did not increase the risk of type 1 somatization. The environ­
mental factors that were most characteristic of type 1 somatizers
(early separation from biologal mother and early placement in adoptive
home) did not make a significant additive contribution to the other
type of somatizers. Nevertheless there was a non-additive interaction
55
between genetic and environmental determinants of type 2 but not
type 1 somatization. Early placement which was characteristic of type
1 somatizers, might also reflect the lower status of biological mothers.
This also occurs in type 2 somatizers in the presence of genetic
susceptibility and low social status in the adoptive home. Genetic and
environmental factors make additive contributions with no interaction
to each somatoform disorder when they are considered separately.
When they are considered jointly the interactions are not additive.
The variables regarding the biological parents that distinguished the
2 types of somatizers and the non-somatizers only accounted for 4.5 %
of the variability. The information about environmental conditions is
restricted to rather crude data. Important environmental variables
such as emotional atmosphere or physiological factors in the adoptive
family are not included in this study.
Type 2 somatization accounted for 12 - 18 % of the population of
adopted women. When a syndrome is as common as this, it is expected
to be more than one combination of genetic and environemntal factors
leading to the final common pathway to the phenotype. Two types of
predisposition, towards petty criminality and male limited alcoholism,
that are genetically independent were each associated with diversiform
somatization. The same genetic factors that lead to petty criminality
and male limited alcoholism in men are expressed as diversiform somati­
zation in women. In some families type 2 somatization is the counter­
part to mild petty criminality among men and the severe female cases
are criminals. This is the same pattern as observed for Briquet's
syndrome and antisocial personality.
Low MAO activity is one factor that has been shown to be associated
with sensation seeking, monotony avoidance, impulsiveness, criminality
and alcohol abuse. These could possibly be factors that are shared by
somatization, petty criminality and type 2 alcoholism (von Knorring
1978, Buchsbaum 1976, Zuckerman 1979, Fowler 1980, Coursey 1982).
It would be valuable in further research to conduct clinical studies
comparing objectively self-report measures of diability with clinical
56
evaluations and neuro-physiological measures or test. Using this
strategy it would be possible to compare the sensitivity and spe­
cificity of alternative assessment techniques.
The results of this study are in line with earlier findings about
psychiatric * illness. Genetic predisposition is a prerequisite, but to
develop psychiatric disorders familial and sociocultural factors are also
necessary. The intrinsic ways in which genetic predisposition is
mediated through enzymatic, biochemical and neuroendocrinological
patterns to personality traits are yet to be discovered.
57
SUMMARY OF THE MAIN RESULTS
Adopted women, although adopted at quite an early age, seem to be
more vulnerable than women in the general population. They have
more psychiatric illness, due to substance abuse and personality
disorders. The adopted women also had an excess of sick-leave mostly
of short duration, with complaints concerning upper respiratory
infection and abdominal symptoms. They also had a higher frequency
of somatization, i.e. more than 2 sick-leaves per year because of
somatic complaints, associated with nervous complaints.
Sick-leaves were not more frequent among adopted men, but sickleaves for psychiatric reasons were longer. The psychiatric disability
was mainly due to substance abuse, personality disorders and neuro­
sis.
Early negative experiences, such as unstable preadoptive placements
did not influence subsequent psychiatric illness. There was some
indication of the existence of a critical period for separation, i.e.
between 6-12 months of age, because placement in the adoptive home
at that age was associated with reactive neurotic depression in adult
life.
Affective disorders in adoptive fathers were significantly associated
with treated depression or substance abuse in adoptees.
There is no significant evidence of genetic influence on occupational
disability and treatment for depression or substance abuse, but there
was a trend towards a non-specific vulnerability in mother-daughter
pairs. No genetic overlap was found between affective disorders and
substance abuse. There was no evidence that psychotic and nonpsychotic depressions are genetically distinct.
There was no support for the diathesis-stress hypothesis, i.e. that a
greater genetic and/or social predisposition is required to bring about
the onset of depression without a precipitant life event.
58
Somatization was correlated with psychiatric disability. 99 % of the
somatizers had either registered or predicted psychiatric disability,
but only 36 % of the women with psychiatric disability had somati­
zation syndrome.
The somatizers could be separated into 2 distinct types. Type 1 (high
frequency) somatizers had frequent psychiatric, abdominal and backcomplaints. They also had a very high frequency of alcohol abuse and
criminality. Type 2 (diversiform) somatizers had more diverse somatic
complaints in general and a lower proportion of their sick-leaves
involved psychiatric complaints. They also had a higher frequency of
alcohol abuse than non-somatizers, but not as high as that among
type 1 somatizers.
Somatization was genetically correlated to alcohol abuse and crimina­
lity. High frequency somatizers had biological fathers with a teenage
onset of criminality and frequent registrations with the Temperance
Board. Diversiform somatizers had either the biological background of
petty criminality or male-limited alcoholism.
Low social status on the part of adoptive fathers was associated with
somatization in women. Diversiform somatizers had a longer contact
with their biological mothers before adoption. Alcohol abuse was more
common among the adoptive fathers of diversiform somatizers.
Both genetic and environmental factors predispose a person to somato­
form disorders. There was a non-additive interaction between genetic
and environmental determinants of diversiform but not high frequency
somatization.
59
APPENDIX I.
<3 months 3-6 months
A. SOMATIC STRESSORS
1. Severe infection (pneumonia, nephritis, syste­
mic infection lasting at least one week or
requiring hospitalisation).
2. Mild viral infection (influenza, mononucleosis
etc, lasting 3 to 6 days).
3. Gross overwork (physical exhaustion due to
excessive activity).
4. Weight loss due to purposal restrictive dieting
(at least 5 kg in 3 months).
5. Use of drugs precipitating depression (reserpine, corticosteroids and other drugs reported
to precipitate depression but not alcohol or
sedatives or other hormones like contracep­
tives) .
6. Other severe physical illness (cancer, neuro­
logical illness, cardiac infarction or physical
damage).
SEVERE AND INDEPENDENT PSYCHOLOGICAL
STRESSORS
1. Death of a household member, closest friend,
first degree relative, grandchild, half-sib or
spouse (including stillbirths and abortions
after first trimester).
2. Serious physical illness in member of house­
hold, first-degree relative, closest friend,
grandchild, half-sib or spouse.
MODERATE AND INDEPENDENT PSYCHOLOGICAL
STRESSORS
1. Unwanted change in financial status (self
fired or unemployed more than one month,
spouse fired or unemployed more than one
month or other change leading to clearly
lowered living standard).
2. Separation or divorce from spouse.
3. Involved with violence.
4. Met with a serious accident.
5. Major changes in home condition due to damage,
repair etc.
60
ACKNOWLEDGEMENTS
Many have participated in several ways in this work and I wish to
express my sincere gratitude especially to:
My husband Lars for supporting me emotionally and for helping me
with the classification of records.
Marika and Björn for being the best children in the world.
My tutor and supervisor professor Michael Bohman for introducing me
into this field and always being most enthustiastic in discussions.
My co-author and instructor of psychiatric genetics professor Robert
Cloninger for giving inspiration in this work.
My co-author Sören Sigvardsson Ph.D. for always supporting me and
being very helpful with computer work.
Professor Carlo Perris for showing great interest and being very
helpful in many ways during this work.
Professor Lars Jacobsson for his kind support.
Greta Lundgren for very skilful assisting and data-collection.
Gunilla Berglund for competent secreterial help and typing of manu­
scripts .
Pat Shrimpton B.A. for her revision of the English langugage.
The work has been supported in part by the Swedish Medical Re­
search Council grant B 82-21X-03789-11, Research Grant from the
Medical Faculty of the University in Umeå, and U.S. Public Health
Service grants AA-03539, MH 31302.
61
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