Journal of Gerontology: PSYCHOLOGICAL SCIENCES
1998, Vol. 53B, No. 2, P73-P85
Copyright 1998 by The Gerontological Society of America
Personality Counts for a Lot:
Predictors of Mental and Physical Health
of Spouse Caregivers in Two Disease Groups
Karen Hooker,1 Deborah J. Monahan,1 Sally R. Bowman,2
Leslie D. Frazier,1 and Kim Shifren1
'Syracuse University.
Oregon State University.
2
The purposes of this study were to examine the influence of personality on mental and physical health of spouse
caregivers and to determine whether there were differences in such influences depending on disease context. The
disease contexts compared were Alzheimer's disease (AD) and Parkinson's disease (PD; with no coexisting dementia)—both chronic, degenerative diseases of later life. It was predicted that personality would be related to mental
and physical health, directly and indirectly, and that AD caregivers would have higher levels ofperceived stress and
worse mental and physical health outcomes. Participants in the study were 175 caregivers (88 AD; 87 PD) living at
home with their ill spouses. The data provided an excellent fit to the hypothesized model of the relationships between personality, disease group, social support, perceived stress, and mental and physical health. Seventy-eight
percent of the variance in mental health was accounted for and 35% of the variance in physical health was explained. Personality had significant direct and indirect effects on mental health and significant indirect effects on
physical health. As predicted, AD caregivers had significantly worse mental health than PD caregivers; however, AD
caregivers had better physical health than PD caregivers, controlling for other variables in the model. These results
are discussed in relation to the existing caregiving and behavioral medicine literature. Future research should include different domains ofpersonality—states and longer term self-regulatory processes in addition to traits—to advance models of caregiving processes further.
W
HERE is the caregiver in caregiving research? While
much is known about the presumed consequences of
caregiving, relatively little is known about what caregivers
themselves bring to the process. Although the stressors of
caregiving are well-documented (e.g., Cantor, 1983; George
& Gwyther, 1986; Poulshock & Deimling, 1984; Pruchno
& Potashnik, 1989; Zarit, Reever, & Bach-Peterson, 1980),
providing care for a family member can have positive as
well as negative impact on a caregiver's life (e.g., Lawton,
Moss, Kleban, Glicksman, & Rovine, 1991; Motenko,
1989; Walker, Acock, Bowman & Li, 1996). The stress associated with caregiving is thought to erode the mental and
physical health of caregivers. Reviews of the literature on
the health consequences of caregiving (e.g., Baumgarten,
1989; Schulz, Visintainer, & Williamson, 1990; Wright,
Clipp, & George, 1993) indicate that, indeed, caregivers are
at increased risk for poor mental health. The effects on
physical health, however, are more equivocal, and a wide
variability among caregivers in mental and physical health
outcomes is noted in many studies. Perhaps part of what determines how life as a caregiver is experienced is influenced
by the type of person one is.
A consistent theme in caregiving research is the attempt
to understand why caregivers under similar circumstances
show such great variability in their ability to adapt to the
situation. Some cope well with overwhelming daily stress,
whereas others do not. The dominant theoretical model has
been the stress and coping framework (Gatz, Bengtson, &
Blum, 1990) originally formulated by Lazarus and Folkman
(1984). According to this model, cognitive appraisal is the
key to understanding the effects of stressors on an individual's well-being. Thus, factors that could affect appraisal,
such as characteristics of the care recipient and resources
and vulnerabilities of the caregiver, have been examined in
an attempt to understand the wide individual differences
seen in coping with caregiving (e.g., Aneshensel, Pearlin,
Mullan, Zarit, & Whitlatch, 1995; Haley, Levine, Brown, &
Bartolucci, 1987; Hooker, Monahan, Shifren, & Hutchinson, 1992; Lawton et al., 1991; Pruchno, Kleban, Michaels,
& Dempsey, 1990; Vitaliano, Russo, Young, Teri, & Maiuro,
1991). This research has led to a better understanding of
predictors of health outcomes. However, as noted by George
(1994), a considerable amount of variance in caregiver outcomes remains unexplained.
Personality and Health
A construct in the cognitive appraisal process that has
been relatively neglected to date is personality. People assign meaning to a situation through an interactive, constructive process in which personality plays a key role,
affecting emotional reactions, coping responses, and eventually even health (e.g., Lazarus, 1991). Inclusion of personality in models of caregiving has the potential to increase our knowledge of caregivers' mental and physical
health. Among general populations, personality has been
shown to be an important predictor of mental and physical
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P74
HOOKER ETAL.
health outcomes (e.g., see Contrada, Leventhal, & O'Leary,
1990; Rodin & Salovey, 1989). Certain characteristics can
put one at risk for specific diseases. For example, hostility
has been shown to be predictive of coronary heart disease
(e.g., Barefoot, Dahlstrom, & Williams, 1983). An alternative view is that certain personality characteristics put one
at risk for disease in general (Friedman & Booth-Kewley,
1987), with the specific disease process likely influenced by
predisposing genetic factors.
Initial results with Alzheimer's disease (AD) spouse
caregivers (Hooker et al., 1992; Hooker, Frazier, & Monahan, 1994; Rabins, Fitting, Eastham, & Zabora, 1990) have
shown that personality is a powerful predictor of mental
health outcomes and coping patterns and a significant predictor of physical health outcomes as well. Among spouse
caregivers of patients with AD and a noncaregiving control
group it was found that high anger-out scores and high hostility scores, combined with the stressors of caregiving, put
individuals at risk for poor blood lipid profiles (Vitaliano,
Scanlan, Frenz, & Fujimoto, in press): Vitaliano and colleagues also found that husband AD caregivers with low
perceived control and wife caregivers with high anger control are at higher risk for weight gain (Vitaliano, Russo,
Scanlan, & Greeno, 1996) than a control group of noncaregiving spouses.
Ultimately, personality of the caregiver needs to be included in models of the caregiving process because the psychological construction of meaning of caregiving in the
caregiver's life will be influenced by personality. How this
affects health depends on a long-term, complex set of interacting processes. A goal for this study was to gain a clearer
understanding of the direct and indirect pathways of the
influence of personality on mental and physical health. We
view our work in a developmental health psychology
framework (see Siegler, 1989) that attempts to bridge two
fairly disparate areas of research. In behavioral medicine,
personality is widely acknowledged to have important links
to health, but rarely are developmental aging processes
given much attention. In contrast, gerontological researchers
consider age and important life contexts in their caregiving
studies, but so far have tended to ignore personological
variables.
Direct effects.—Personality could have a relatively direct
effect on mental and physical health in that it may predispose caregivers to interpret events and people in the environment as benign or as threatening. Thus, depending on
personality, some caregivers may perceive that they are
under more stress than others, even in relatively equivalent
caregiving situations. Perceptions of stress are linked to
physiological mechanisms such as cardiovascular reactivity
and immune-system downregulation that over time can
contribute to chronic health problems (Anderson, KiecoltGlaser, & Glaser, 1994). For example, in a longitudinal
study of AD family caregivers (Kiecolt-Glaser, Dura, Speicher, Trask, & Glaser, 1991) immune system functioning
was lower, and remained lower over time, than in a comparable noncaregiving group.
There are compelling data (e.g., Bolger, 1990; Cozzarelli, 1993; Ewart & Kolodner, 1994) indicating that stress
is partially a "person" variable. For example, people high in
neuroticism experience different life events, interpret them
more negatively, and have the propensity to be more negatively affected by chronic stress than people low in neuroticism (e.g., Aldwin, Levenson, Spiro, & Bosse, 1989;
Bolger & Schilling, 1991; Magnus, Diener, Fujita, & Pavot,
1993; Ormel & Wohlfarth, 1991). Neuroticism has been
conceptualized as a broad, trait-like personality variable potentially affecting health (e.g., Bromberger & Matthews,
1996). Indeed, previous work with AD spouse caregivers
has found it to be negatively related to health and wellbeing (Hooker et al., 1992). Therefore, neuroticism was one
of the personality variables included in this study.
Another personality variable that has been extensively
studied in relation to health is optimism. Carver and Scheier
(1991) have outlined a control theory of self-regulation in
which optimism plays an important role in the stress process. Individuals with positive expectations about the future
and their ability to cope with what the future brings (i.e.,
optimists) are likely to maintain their goal-oriented efforts
longer, resulting in more positive outcomes over time. Optimism has been shown to predict not only self-ratings of
health, but also hard outcomes such as new Q-waves on
the EKGs of patients undergoing coronary artery bypass
surgery (Scheier et al., 1989) and nurses' health ratings 6
month postoperatively for heart transplant patients (Leedham, Meyerowitz, Muirhead, & Frist, 1995). Bromberger
and Matthews (1996) prospectively studied midlife women
and found that those low in optimism at the baseline assessment were more likely to experience depressive symptoms
approximately 3 years later, especially if they had stressful
ongoing problems. Interestingly, it has been documented
that spouse caregivers for patients with dementia can show
considerable variation in optimism over time (Shifren &
Hooker, 1995a). Thus, optimism was included in this study
because it is a personality variable that is potentially malleable based on the ups and downs of everyday experiences
and has been linked to health (Reker & Wong, 1985).
Indirect effects.—Personality may also play an indirect
role in affecting health outcomes by its relationship to social support. Positive relationships between social support
and health have been shown in numerous studies (e.g.,
Berkman & Syme, 1979; see House, Landis, & Umberson,
1988 for a review). Although social support has been operationalized in a number of ways both structurally (e.g., existence and type of connections in a network) and functionally (e.g., types of resource provided such as instrumental
aid or psychological support), there is evidence that it is
one's perception of support that is most crucial in predicting
the buffering effect of social support on stress (e.g., Barrera,
1981; Wethington & Kessler, 1986). The stress-buffering
hypothesis (Cohen & Wills, 1985) is based on findings that
positive interpersonal relationships may attenuate the adverse changes in physiological functioning (e.g., suppressed
immune function, increased cardiovascular reactivity) associated with stress (e.g., Baron, Cutrona, Hicklin, Russell, &
Lubaroff, 1990; Jemmott & Magloire, 1988).
Uchino, Kiecolt-Glaser, and Cacioppo (1992) found that
AD caregivers high in social support show different pat-
PERSONALITY AND CAREGIVING
terns of heart rate reactivity and blood pressure than do
those low in social support. This may have significance for
physical health, as it has been found that high cardiovascular reactivity is related to immune system responses
(Kiecolt-Glaser et al., 1991). Kiecolt-Glaser et al. (1991)
found that spouse caregivers of dementia patients who reported lower levels of social support at the beginning of
their longitudinal study were particularly likely to show
poorer immune function at 1-year follow-up. Redinbaugh,
MacCallum, and Kiecolt-Glaser (1995) found that caregivers at risk for recurrent depression over a 3-year period
were those who had persistent deficits in social support, experienced more negative life events, and had higher perceived stress scores.
Previous research with AD spouse caregivers showed
that perception of social support was a significant predictor
of self-reported health (Monahan & Hooker, 1995). This is
consistent with literature generally showing that caregiver
burden is eased when social support is perceived as adequate (e.g., Clipp & George, 1990; George & Gwyther,
1986; Johnson & Catalano, 1983; Vitaliano et al., 1991) and
is worse when support is perceived to be inadequate. A
point not often made is that personality may be a predictor
of social support (e.g., see Connell & D'Augelli, 1990;
Hansson & Carpenter, 1990). For example, people predisposed to experiencing negative affect (i.e., high in neuroticism) may not have as strong support networks, or may be
less skilled than others at being able to tap into that support
network, especially if they are enduring the chronic stressors associated with caregiving. Thus, a test of an indirect
pathway by which personality relates to health outcomes,
through social support, will be conducted.
An auxiliary question that is addressed in this study is
whether giving care to someone who is losing his or her
mental capacities is associated with more negative outcomes for the caregiver. While there are few comparative
studies of well-defined disease groups, some studies do
show dementia caregivers to be at greater risk for negative
outcomes (Birkel, 1987; Birkel & Jones, 1989; Clipp &
George, 1993; Reese, Gross, Smalley, & Messer, 1994).
However, others find no differences between caregiving
groups (Cattanach & Tebes, 1991; Liptzin, Grob, & Eisen,
1988; Rabins et al., 1990) or even find an advantage for
caregivers of cognitively impaired patients compared with
physically disabled patients (e.g., Yu et al., 1993).
In this study we chose to contrast AD spouse caregivers
with Parkinson's disease (PD) spouse caregivers. These disease groups, the former including dementia and the latter
not, were targeted because many potentially confounding
variables are controlled for with these populations. Both
AD and PD are chronic diseases in which later life onset is
most common, and both show variable and unpredictable
patterns (which can be stressful for caregivers). In neither
disease is there immediate danger of death, and yet symptoms that are manifested in both AD and PD are intrusive
and would affect a caregiver's daily routine (e.g., Levin &
Weiner, 1987; Mendelsohn, Dakoff, & Skaff, 1995; Vernon
& Stern, 1988). In addition, both diseases are progressive
and irreversible. In AD the most common symptoms are the
loss of cognitive capacities, especially memory. In contrast,
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PD produces progressive degeneration of motoric function,
and primary symptoms include tremor, rigidity, bradykinesia (slowness in activating movement), stiffness, and difficulty with balance and walking (e.g., Delwaide & Gonce,
1988; Stern, 1988). Drug treatments to alleviate symptoms
are available but may lose effectiveness over time (Lesser et
al., 1979; Muenter, 1982).
Although a subset of PD patients develop dementia, for
the purposes of this study only caregivers of PD patients
with no coexisting dementia were included in order to make
a clean comparison of caregivers of demented patients with
caregivers of those exhibiting only physical disabilities. We
predicted that AD caregivers would have higher levels
of perceived stress and worse mental and physical health
outcomes.
In sum, the goals of this study were twofold: (1) to examine the direct and indirect effects of personality on mental and physical health of spouse caregivers, and (2) to examine two well-defined groups of caregivers to see whether
disease status of the care recipient was related to perceived
stress and mental and physical health outcomes.
METHOD
Participants
There were 175 spouse caregivers (88 AD; 87 PD) recruited from a wide variety of sources in Central New York
including a hospital-based dementia evaluation clinic, local
neurologists' offices, AD and PD support groups, newspaper ads and articles, public service announcements, local
churches, and health fairs. Screening criteria included (1)
confirmed diagnosis of AD or PD, (2) diagnosis at least 1
year previously, (3) caregiver and spouse had to be living in
the same household, and (4) PD patients had to be cognitively intact. Both AD and PD patients were screened for
cognitive impairment with the Folstein Mini-Mental State
Exam (MMSE; Folstein, Folstein & McHugh, 1975). Following the NINCDS-ADRDA Workgroup Guidelines (McKhann et al., 1984), PD patients who scored below 24 on the
MMSE were not considered cognitively intact. Therefore,
three of the PD spouses we interviewed were not considered in our data analyses because their spouses scored below 24 on the MMSE.
AD caregivers.—Of the 88 AD caregivers, 52 (59.1%)
were female and most were Caucasian (95.5%). Three caregivers were African American and one was Asian. Thus,
only 4.5% of the AD sample comprised minority caregivers.
According to 1990 Census records, minorities represent
2.7% of the population over age 65 in Onondaga County,
New York (where most of our recruiting efforts were aimed),
and 61.3% of this population is female, so our sample is
not unrepresentative of the elderly population in this geographic locale. It should be noted that we did everything
possible to recruit as inclusive a group of caregivers as possible. The average age of the caregivers was 70.2 years (SD
= 9.5 years), and ages ranged from 39 to 89 years. The average age of the care recipient was 73.7 years (SD = 9.8
years) and ranged from 40 to 93 years. Caregivers had been
married an average of 43.4 years (SD =13.8 years) and had
P76
HOOKERETAL
been caregiving an average of 4.4 years (SD = 3.7 years).
Socioeconomic status (SES) according to Hollingshead's
(1975) Four Factor Index averaged 41.6 (SD = 12.9), which
places most of the sample in a status equivalent to minor
professionals and technical workers. Number of years of education averaged 13.3 (SD = 3.6 years).
PD caregivers.—Of the 87 PD caregivers, 55 (63.2%)
were female and all but one (an African American) were
Caucasian. The average age of the caregivers was 67.1
years (SD = 8.6 years) and ages ranged from 41 to 82 years.
The average age of their spouses was 68.8 years (SD = 8.7
years) and ranged from 45 to 85 years. Caregivers had been
married an average of 39.6 years (SD = 12.6 years) and had
been caregiving an average of 7.6 years (SD = 7.1 years).
SES according to Hollingshead's (1975) Four Factor Index
averaged 45.2 (SD = 11.6), placing most of the sample in a
status equivalent to minor professionals and technical
workers. Number of years of education averaged 13.9 (SD
= '2.8 years) so the average caregiver in this sample had
about 2 years of higher education.
Strengths of the sample are the approximate equivalence
in terms of numbers of participants in disease groups and
relatively even numbers of husbands and wives. A weakness is the low number of minority caregivers despite our
extensive recruiting efforts.
Measures
Personality.—An abbreviated version of the NEO Personality Inventory (Costa & McCrae, 1985, 1989), the
NEO-Five Factor Inventory (NEO-FFI) was utilized to
measure personality traits. This briefer inventory was chosen over the more lengthy one because of time constraints
in conducting interviews with caregivers. The NEO-FFI is a
60-item instrument with 12 items measuring each of the
five broad personality domains, but for the purposes of this
study only neuroticism (N), the tendency to experience
emotional distress, was utilized. The NEO-FFI has good
psychometric properties and corresponds well with the full
181-item instrument (Costa & McCrae, 1985; 1989). The
new norms for the NEO-FFI were used in creating t scores
from the raw data. Cronbach's alpha (internal consistency)
coefficient for the Neuroticism scale was .77.
Optimism, an important positive aspect of personality related to health, was operationalized in this study with the
Life Orientation Test (LOT; Scheier & Carver, 1985), a
measure of dispositional optimism. Previous research with
the LOT has established its strong psychometric characteristics (e.g., Scheier, Carver, & Bridges, 1994), and Cronbach's alpha for the LOT was .71 in this sample. Although
a slightly revised version of the LOT is now recommended
(Scheier et al., 1994), this measure was not available at the
time the study was designed.
Social support.—Caregivers' subjective appraisals of social support were assessed with the Social Support Appraisals (SSA) scale (Vaux et al., 1986). This 23-item scale,
which measures the degree to which one feels loved, respected, and involved, has shown good validity and high re-
liability across diverse samples, including older adults. Cronbach's alpha for the SSA scale for this sample was .89.
Perceived stress.—We assessed the degree to which the
caregivers felt stressed and challenged. We chose a stress
appraisal instrument that was not specifically linked to
caregiving per se, as recommended by George and Gwyther
(1986). The measure we used was the Perceived Stress
Scale (PSS), a reliable and valid 14-item measure designed
to assess the degree to which situations are appraised as
stressful (Cohen, Karmack, & Mermelstein, 1983). It has
been used successfully with diverse samples, including dementia caregivers (e.g., Hooker et al., 1992). Sample items
from this scale are, "In the last month, how often have
you felt that you were effectively coping with important
changes in your life?" and "In the last month, how often
have you been able to control the way you spend your
time?" Response categories are never (4), almost never (3),
sometimes (2), fairly often (1), and very often (0). Thus,
higher scores indicate more perceived stress. Cronbach's
alpha for the PSS in this study was .87.
Mental health.—Se\eral mental health indicators were
included in this study, including the widely used Center for
Epidemiological Studies Depression Index (CES-D; Radloff, 1977), a 20-item scale used to assess the overall level
of depression experienced in the past week. It has shown
strong psychometric characteristics in many studies, including studies specifically using samples of spouse caregivers
(e.g., Hooker et al., 1992; Pruchno & Resch, 1989). Cronbach's alpha for the CES-D with this sample was .86. Higher
scores indicate more depressive symptomatology.
The 10-item Bradburn Affect Balance Scale (Bradburn,
1969) was another indicator of mental health and is especially useful because it includes both positive affect and
negative affect subscales. These subscales are brief (5 items
each), so it is not surprising that Cronbach's alphas were relatively low (.54 for positive affect, .67 for negative affect)
for this sample. Following Bradburn's procedures, a single
score was derived by subtracting negative affect scores from
positive affect scores and adding a constant of 5 to each
score (to avoid the possibility of any negative scores). Thus,
scores range from 0 to 10, with higher scores representing
higher current levels of psychological well-being.
A third measure of mental health was the state anxiety
score from Spielberger's State-Trait Anxiety Inventory
(STAI, Form Y; Spielberger, 1980). Each scale (trait and
state) contains 20 items and has been shown (e.g., Buros,
1978; Levitt, 1967) to have strong psychometric properties.
Previous research has shown that the STAI is appropriate
for use with older adults (Usala & Hertzog, 1990). In this
study we did not include the Trait Anxiety scale scores in
our analyses because we expected that these scores would
be highly correlated with neuroticism. Trait anxiety is conceptually related to personality and thus should not serve as
an outcome measure of mental health in this study. State
anxiety, however, seems quite relevant for understanding
the caregiver's mental well-being. Previous research has
shown that a caregiver's level of anxiety can fluctuate from
day to day (Shifren & Hooker, 1995b). Cronbach's alpha
PERSONALITY AND CAREGIVING
for state anxiety was .92 in this sample. Higher scores indicate higher levels of anxiety.
Physical health.—There are three indicators of physical
health, two of which were modeled after the Multi-level Assessment Instrument (MAI; Lawton, Moss, Fulcomer, &
Kleban, 1982) and one being the Current Health subscale of
the Health Perceptions Questionnaire (HPQ) used in the
Rand Health Insurance Experiment. The Current Health subscale is a 9-item measure with extensive information on reliability and validity (Davies & Ware, 1981) and was designed
to provide good discrimination at the less dysfunctional end
of the illness continuum. Cronbach's alpha for this scale was
.89. Higher scores indicate better perceived health.
A general self-report health index was created by summing scores from five items commonly used in health research. The questions were (a) "In general, would you say
your health is excellent, good, fair or poor?" with responses
being excellent (4), good (3), fair (2), or poor (1); (b) "During the past three months how much pain have you had?"
with responses being a great deal of pain (1), some pain (2),
a little pain (3), or no pain (4); (c) "During the past three
months, how much has your health worried or concerned
you?" with responses being a great deal (1), somewhat (2),
a little (3), or not at all (4); (d) "Do your health problems
stand in the way of your doing the things you want?" with
responses being not at all (3), a little (2), or a great deal (1);
and (e) "Would you say that your health is better, about the
same, or not as good as most people your age?" with responses being better (3), the same (2), or not as good (1).
Responses on all five items were summed, and the Cronbach's alpha for this health index was .71, higher scores
represent better perceived health. These types of self-rated
health questions have consistently been found to predict
morbidity and mortality (e.g., Idler & Kasl, 1991; Kaplan,
Barell, & Lusky, 1988).
Chronic conditions is a checklist of 20 health conditions
reportedly diagnosed by a doctor (e.g., diabetes, hypertension, heart trouble, arthritis, etc.) and is one of the subindices of the MAI. Caregivers answered "yes" (1) or "no"
(0) to 20 chronic conditions and had the opportunity to
mention other conditions that were not on the list. The MAI
was designed for use with older adults, and the psychometric properties of each of its domains and subindices are well
documented (Lawton et al., 1982). We added up the number
of chronic conditions reported to get an overall measure of
number of chronic conditions. Higher scores indicate worse
health (i.e., more chronic conditions).
Procedure
Potential participants were recruited through the organizations and strategies described above. Potential participants who wanted more information either returned a
preaddressed, stamped postcard (if recruited by letter), or
they called our office. A member of the research team
spoke with the caregiver on the telephone and described the
study. A brief initial screening was done over the phone to
make sure that the caregivers met our criteria for inclusion
in the study. Questions asked were (a) "Has your spouse
been diagnosed with AD/PD?" (presence of either AD or
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PD, depending on recruiting source); (b) "Is your spouse
showing any memory loss?" (PD caregivers who answered
this question affirmatively were excluded from further consideration for participation); (c) "How long has it been
since the diagnosis was made?" (caregivers with at least 1
year experience were sought so that the caregiving role was
well-established); and (d) "Is your spouse currently living
at home?" Only those spouses who were living together
were eligible for participation in order to minimize variance
attributed to different living situations (e.g., spouse in a
long-term care facility vs living with the caregiver). If the
caregiver qualified for inclusion and remained interested in
participating in the study, an interview was scheduled.
A multistage procedure was used to collect the data.
Caregivers were interviewed in their homes by one of two
trained psychology doctoral students. The length of the interviews varied from about 40 minutes to several hours, but
typically lasted approximately 1.5 hours. Caregivers were
paid $25 for their time.
To limit the length of the in-home interview, the SSA,
HPQ, and ABS (along with some other measures not relevant for this study) were collected via mailback questionnaires. Caregivers were provided with a stamped addressed
mailer in which to return the questionnaires. The interviewer carefully went over the instructions for completing
the questionnaire, and the instructions were also printed on
the measures themselves. Caregivers were instructed to try
to return these within 1 week. If questionnaires were not received within 10 days, a member of the research team (usually the interviewer) called to gently remind the person to
return the questionnaire. Compliance with this procedure
was excellent, as only nine people (5%) failed to return the
materials. Interestingly, eight of the nine caregivers who did
not return the questionnaires were AD caregivers, which is
perhaps an unobtrusive indicator of the amount of stress in
their lives as compared with PD caregivers.
Analytic Strategies
To examine demographic differences between the two
groups of AD and PD caregivers, we used a multivariate
analysis of variance (MANOVA). We used structural equation modeling to examine the relationships between personality, disease group, social support, stress, mental health
and physical health. Since age is related to physical health
status, a direct path from age to physical health was included in the model. The model of personality and health
presented in Figure 1 was estimated with maximum likelihood estimation using LISREL 8.12 (Jbreskog and Sorbom,
1993). The observed variables of optimism (LOT), wellbeing (ABS), and physical health-number of conditions
(NUMCOND) were reversed in these analyses so that the
latent constructs were defined with variables scored in the
same direction.
RESULTS
Test of Demographic Differences Between Groups
A multivariate analysis of variance (MANOVA) was conducted to determine whether the two groups of caregivers
differed significantly on the demographic variables of sex,
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HOOKER ETAL.
age, spouse's age, length of marriage, number of years caregiving, education, or SES. This type of analysis is preferable to multiple Mests because there is less likelihood of a
Type I error. Based on results from the MANOVA, Wilks'
Lambda = .81, F(7,140) = 4.79, p = .0001, we' rejected the
null hypothesis that there were no significant differences
between the two disease groups. Follow-up F-tests showed
that the AD caregivers were significantly older [F(l,146) =
6.28, p = .01] than the PD caregivers (by 3.4 years on average), and the spouses (AD patients) were significantly older
[F(l,146) = 11.78, p = .001] than the PD patients as well (5
years on average). However, the PD caregivers had been
caregiving for a significantly longer period of time [F( 1,146)
= 13.18,/? = .000] than the AD group (almost 3 years longer
on average). There were no other significant differences on
any of the demographic variables.
Structural Equation Model
Table 1 shows the means and standard deviations, by disease group, of the variables that were used in the structural
equation model. Table 2 shows the correlations of these
variables with one another.
In the conceptual model presented in Figure 1, the exogenous variables are personality, disease group, and age. It
was hypothesized that personality affects social support,
stress, and mental health directly, and physical health only
indirectly. It was hypothesized that disease group affects
stress, mental health, and physical health directly. Further,
social support was hypothesized to affect stress and mental
health directly; stress was predicted to affect mental health,
and it was expected that a reciprocal relationship would
exist between mental and physical health. And finally, age
was predicted to affect physical health.
Imputation of Missing Data
A variety of strategies are currently available for the
treatment of missing data. Researchers have found, however, that utilizing listwise deletion, pairwise deletion,
mean substitution, and multiple regression imputation are
less preferable than maximum likelihood (ML) estimation
techniques. ML estimation techniques produce estimates
that are consistent and efficient when the cause(s) of the
missing data is random (Muthen, Kaplan, & Hollis, 1987).
The extent of missingness in the data was minor (less than
2%). Although trivial, the inclusion of the additional 9 participants who had some missing data to the listwise sample of
163 increases the power of analyses for model testing. We
used a procedure known as expectation maximization (EM),
which is explained in detail in Graham, Hofer, and Piccinin
(1994). Briefly, EM initially uses multiple regression to impute a value for a missing score, adds random error, estimates a covariance matrix, and then repeats this process each
time a missing value is imputed (Rubin, 1987). EM is now
an option in the Missing Values Analysis in SPSS Version 7.5
for Windows 95 and was used in our analyses.
Model identification.—The model was identified using
Bollen's (1989) two-step approach. First, the measurement
model was tested using confirmatory factor analysis. The
metric of the seven intercorrelated latent variables was
fixed by setting the metric of one of the loadings to 1.0. For
variables that had only single indicators, the error terms
were fixed. Thus, loadings and error terms for these variables are identified. Then Bollen's (1989, pp. 244-246)
two-indicator rule can be used to show that the other parameters (loading, error terms, correlations between latent
variables and their variances) are identified (R. O'Brien,
personal communication, November, 1996). In the second
step the parameters for the structural part of the model (i.e.,
the paths between the latent variables, error terms for the
latent variables, covariance between the error terms for
mental and physical health) are all identified by the rank
condition (Bollen, 1989, pp. 98-103).
The model in Figure 1 was tested for model fit based on
multiple criteria (Bentler & Bonett, 1980), including the
chi-square test statistic, Tucker-Lewis Index (TLI), Comparative Fit Index (CFI), and Goodness of Fit Index (GFI).
The results of the hypothesized structural model in Figure 1
Table 1. Means and Standard Deviations
as a Function of Caregiving Group
Age
Figure 1. Model of relationships between personality and health among
spouse caregivers of Alzheimer's disease (AD) and Parkinson's disease
(PD) patients. Solid paths are statistically significant in the structural
equation model; broken paths are nonsignificant. See Table 3 for parameter estimates for these direct paths.
Variable
PD Spouse
Caregiver
Mean (SD)
AD Spouse
Caregiver
Mean (SD)
Age
Number of years caregiving
Neuroticism (N)
Optimism (LOT)
Social support (SS)
Perceived stress (PSS)
Depression (CES-D)
State anxiety (STAI)
Well-being (ABS)
Health index (HEALTH)
Health questionnaire (HPQ)
Chronic conditions (NUMCOND)
67.1 (8.6)
7.6 (7.1)
48.5 (9.3)
30.9 (5.7)
70.2 (6.8)
19.5 (8.1)
9.8 (7.5)
34.9(11.1)
7.0 (2.1)
13.9 (2.5)
31.6 (7.8)
2.3 (1.7)
70.2 (9.5)
4.4 (3.7)
50.6 (9.2)
29.3 (6.0)
70.2 (8.8)
22.9(10.2)
15.1 (11.1)
40.8(13.5)
6.6 (2.1)
13.9 (2.9)
31.3 (7.8)
2.4 (1.6)
Note: n = 84 for the Parkinson's disease (PD) group; n =
Alzheimer's disease (AD) group.
for the
PERSONALITY AND CAREGIVING
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Table 2. Intercorrelations of Personality, Social Support, Perceived Stress, Mental Health,
and Physical Health Variables by Disease Group
Age
Neuroticism (N)
Optimism (LOT)
Social support (SSA)
Perceived stress (PSS)
Depression (CES-D)
Well-being (ABS)
State anxiety (STAI)
Health questionnaire (HPQ)
Health index (HEALTH)
Chronic conditions (NUMCOND)
AGE
N
LOT
SS
PSS
CES-D
ABS
STAI
HPQ
HEALTH
NUMCOND
—
.00
-.17
-.24
.03
.26
-.12
.14
-.28
-.10
.30
-.06
—
-.56
-.26
.46
.43
-.41
.40
-.22
-.37
.14
-.01
-.47
—
.24
-.45
-.35
.34
-.33
.32
.35
-.16
-.17
-.18
.21
—
.00
-.18
.26
-.19
-.03
-.01
.11
-.06
.61
-.59
-.15
—
.51
-.28
.46
-.23
-.30
.03
.01
.55
-.61
-.28
.74
—
-.48
.53
-.46
-.34
.11
.06
-.43
.53
.31
-.62
-.63
—
-.48
.31
.27
-.15
.06
.44
-.50
-.20
.62
.67
-.57
—
-.45
-.36
.15
-.07
-.29
.33
.17
-.34
-.40
.43
-.35
—
.69
-.55
-.05
-.30
.34
.13
-.41
-.51
.45
-.39
.73
—
-.61
.19
.20
-.20
-.16
.18
.34
-.21
.19
-.62
-.59
—
Note: Parkinson's disease caregiver (n = 84) correlations are in the lower diagonal; Alzheimer's disease caregiver (n = 88) correlations are in the upper
diagonal. Correlations of-.21 or greater are significant atp < .05; correlations of ±.28 are significant at/? < .01. LOT = Life Orientation Test; SS = Social
Support Appraisals; PSS = Perceived Stress Scale; CES-D = Center for Epidemiological Studies Depression Index; ABS = Bradburn Affect Balance Scale;
STAI = State-Trait Anxiety Inventory; HPQ = Health Perceptions Questionnaire.
showed an excellent fit, x2 (df = 42, n = 172) = 51.20, p =
.16, CFI = .99, GFI = .95, TLI = .98.
Mental Health
Direct effects.—Examination of the individual parameter
estimates in Table 3 reveals that there were several significant paths related to mental health. Specifically, personality
(higher neuroticism/lower optimism) was significantly related to lower social support, higher perceived stress, and
worse mental health. In addition, higher levels of stress
were significantly related to worse mental health. There
was a trend at the .10 level for lower levels of social support to be related to higher stress. The direct path from social support to mental health was not significant. There was
also a significant path from disease group to mental health,
indicating that AD caregivers had significantly worse mental health, as hypothesized.
Indirect effects.—One advantage of a structural equation
model is that indirect effects can also be examined and
tested statistically. Table 4 shows the estimates of indirect
effects in the model. The only significant indirect effect on
mental health was the indirect path of personality to mental
health (through stress). These results show that personality
does have strong direct and indirect effects on mental health.
Fully 78% of the variance in mental health of caregivers was
explained by this model.
Physical Health
Direct effects.—The model was less successful in predicting physical health, although over a third (35%) of the
variance was accounted for by the model. There were two
significant predictors of physical health: mental health,
demonstrating that caregivers who score poorer in mental
health measures also have poorer perceived physical health,
and disease group, such that AD caregivers had better perceived physical health. In addition, we tested a number of
other paths that failed to achieve significance. Direct paths
Table 3. Parameter Estimates for the Model
of Personality and Health
Parameter
Estimate
Direct effects
Personality -> Social support
Personality -» Stress
Personality -> Mental health
Disease -> Stress
Disease -» Mental health
Disease -> Physical health
Age -» Physical health
Social support -* Stress
Social support -» Mental health
Stress -> Mental health
Mental health -> Physical health
Physical health -» Mental health
Unstandardized Standardized
t
Coefficient
Coefficient value"
-0.34
1.08
0.48
0.99
2.74
2.01
-0.08
0.17
-0.08
0.25
-0.39
-0.58
-0.30
0.78
0.38
0.05
0.16
0.16
-0.12
0.14
-0.08
0.28
-0.50
-0.44
-3.17
7.09
2.46
0.82
2.65
2.02
-1.65
1.98
-1.36
2.37
-5.27
-1.27
Note: Names of parameter estimates correspond to variables and paths
in Figure 1.
't values above 1.960, 2.576, and 3.291 are significant at p < .05, p <
.01, and p < .001, respectively, t values above 1.645 represent a trend at
p<A0.
to physical health from personality, social support, and
stress were all insignificant.
Indirect effects.—As shown in Table 4, the significant effects on physical health in this model are largely indirect
ones. There was a highly significant indirect path from personality to physical health (through stress and mental
health) such that caregivers high in neuroticism and low in
optimism reported worse physical health. There was also a
significant indirect effect of stress on physical health
(through mental health) such that those with higher stress
had worse health. These indirect effects funneled through
mental health are in addition to the significant direct effect
of mental health on physical health.
Another path in the model that deserves mention because
it was hypothesized to be significant was the direct path
HOOKER ETAL.
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Table 4. Estimates of Indirect Effects in Structural
Model of Personality and Health
Parameters
Personality to:
Variables
Stress
Mental health
Physical health
Disease to:
Mental health
Physical health
Age to:
Mental health
Physical health
Social support to:
Mental health
Physical health
Stress to:
Mental health
Physical health
Unstandardized
Coefficients
{t values)
-0.06
(-1.45)
0.51
(3.48)***
-0.38
(-4.33)***
-0.38
(-0-42)
-0.91
(-1.88)
0.06
(1.24)
-0.02
(-1.21)
0.03
(0.78)
0.02
(0.63)
0.07
(1.12)
-0.13
(-2.51)**
Mental health to:
Physical health
-0.11
(-0.91)
Physical health to:
Mental health
-0.17
(-0.55)
Note: Numbers in parentheses are t statistics.
**p<. 01 ;***/?<. 0005.
from disease status to stress. This path was not significant,
so our hypothesis that AD caregivers would fare worse than
PD caregivers on all measures was not upheld. Additionally, we explored the possibility that AD caregivers had
lower levels of social support, but the path from disease to
social support was not significant either.
DISCUSSION
Living with a spouse who is experiencing losses in the
cognitive or physical domain is undoubtedly a stressful, lifechanging experience. Among all the roles people occupy,
Aneshensel et al. (1995) characterize the caregiving role as
"the most relentlessly imperialistic" (p. 37). While Brody
(1981) has argued that caregiving is becoming a normative
developmental task, it is, of course, never anticipated in a
positive sense and is an unscheduled, unpredictable part of
life's passage, making it a unique time in people's life
course. People can and do accommodate to the stresses of
caregiving, and it can be a rewarding growth experience. For
example, caregivers often report more positive changes in
self-concept than negative changes as a result of caregiving
(Aneshensel et al., 1995). To put a personal face on how
people deal with these stressors we must include aspects of
the caregiver's personality in models of caregiving.
We are puzzled by the continuing reluctance of caregiving researchers to consider personality as an important predictor of how people negotiate the stressors associated with
caregiving. This may be due to an unnecessarily narrow
conception of personality. For example, Pearlin and Skaff
(1996) argue that work centered on the continuity of personality through time lacks synergism necessary for inclusion in frameworks of stress and the life course. However,
mastery or self-efficacy, considered as a stress-buffering
moderator in a most recent model (Aneshensel et al., 1995),
could be construed as a personality characteristic.
Personality continuity does not imply immutability. Indeed, the interactionist perspective stipulates that individuals
in the social environment are acting on one another. Studies
of personality development over the life course (e.g., Caspi,
Bern, & Elder, 1989; Caspi & Silva, 1995) have shown how
individual differences among young children lead to differential life experiences, which in turn amplify those initial differences. Such circular feedback functions (e.g., Schneirla,
1957) have recently been discussed in relation to models of
adult personality development (e.g., Light, Grigsby, &
Bligh, 1996) as a possible explanation for the increasing
heterogeneity of personality among older adults.
Effects of Personality on Mental Health
Results show strong effects of personality on mental
health, both directly and indirectly through stress and social
support. A large portion of variance (78%) in mental health
was accounted for by the variables in the structural equation model. Mental health is an indication of adaptation to
life experiences. It is sometimes argued that personality has
an effect on mental health because it channels the experiences one is likely to encounter; for example, people high
in neuroticism may seek out negative life experiences (e.g.,
Bolger & Schilling, 1991; Ormel & Wohlfarth, 1991) that
lead naturally to depression or lower well-being. This "top
down" influence of personality on life events has been confirmed in some studies (e.g., Suh, Diener, & Fujita, 1996).
In this study personality was disattenuated from the initial event or sequelae of events that the caregiver experienced. One does not control or influence the life event of a
spouse becoming ill with AD or PD. Everyone in the study
was operating under the stressors associated with caregiving, and personality could not be construed as a producer of
these life circumstances. It is possible that personality variance was greater than in situations where "niche-picking"
(Scarr & McCartney, 1983) or self-selection into certain environments is possible (see Light et al., 1996). Therefore,
caregiving may be a strategic context in which to examine
effects of personality on health.
Perceived stress.—While personality had a significant direct effect on mental health, the strongest effect in our
model was the association between personality and perceived stress. Thus, our results are consistent with previous
studies that show stress to be partially a person variable
(e.g., Bolger, 1990; Cozzarelli, 1993; Ewart & Kolodner,
1994). Aneshensel et al. (1995) have noted that caregivers
can experience the same primary stressor, yet experience
very different secondary stressors. This encroachment of
PERSONALITY AND CAREGIVING
stress into other areas of the caregivers' lives, what Aneshensel et al. call "stress proliferation," could be influenced
by personality.
Perceived stress is a complex psychological construct.
Personality factors may partially explain why the outside
world gets interpreted through a perceptual filter that assigns meaning to events as benign or threatening. But factors other than personality play a large role in the stress
process. As expected, based on past literature (Lazarus &
Folkman, 1984), perceived stress had a significant direct effect on mental health independent of personality. This is
consistent with a previous study in which it was found that
neuroticism accounted for some, but not all, of the relationship between stress and psychological symptoms (Aldwin
etal., 1989).
The unexpected finding that disease group (e.g., caring
for a spouse with AD vs PD) made no difference in perceived stress (when considered in the multivariate model) is
perplexing given the well-documented findings regarding
chronic stress among AD caregivers. However, most of
these studies have included only AD caregivers or compared AD caregivers with a noncaregiving control group.
Perhaps it is not that much more stressful, on an individual
basis, than living with a spouse with physical impairments.
Proponents of social comparison theory (Festinger, 1954)
argue that people are motivated to evaluate the self by making relevant social comparisons. Additionally, in studies designed to test recent reformulations of social comparison
theory (Wood, 1989), it has been found that people are motivated to evaluate themselves in ways that promote selfenhancement. Thus, caregivers may seek to compare themselves with others whom they perceive to be worse off on
important dimensions. These downward social comparisons
(Wills, 1981) protect self-esteem and are particularly likely
to operate during times of stress or threat (Taylor & Lobel,
1989). Caregivers may be likely to compare themselves
mentally to others in similar situations such that AD caregivers might not rate themselves as overwhelmingly more
stressed than PD caregivers. Also, by later life (Suls &
Mullen, 1982) it becomes possible to compare one's current
situation with one's past situations. On the basis of temporal comparisons one might not expect large differences between caregiving groups; people in both groups might feel
quite stressed in their current situation compared with their
past. These social cognitive explanations for the lack of
group differences in perceived stress among AD and PD
spouse caregivers are wholly speculative, but deserve attention in future research.
Social support.—Part of the reason that personality has
such a strong effect on mental health is because of its link to
perceived social support. A plethora of studies have shown
that perceived social support is an important correlate of
mental and even physical health (e.g., Cohen & Wills,
1985), but how perceived support actually operates is still
an important research question (Lakey, McCabe, Fisicaro,
& Drew, 1996). Caregiving has been most often studied in
relation to diseases that strike in later life, which means that
the spouse caregiver, as a person, has had a lifetime of experiences that affect who one is and how one deals with stress.
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We hypothesized that some people, because of their personal characteristics, would have a well-entrenched social
network and place in the world, while others may have impoverished social supports in part because they are not the
type of people with whom one would choose to spend time.
Lakey et al. (1996) state that there has been surprisingly little research on personality factors that predict development
of perceived support, but the data that are available (Connell
& D'Augelli, 1990; Hansson & Carpenter, 1990; Lakey,
1989) indicate that personality does play a role. This conclusion was upheld in our study, as personality was significantly related to perceived support.
Social support was related to perceived stress in our
study, which in turn was related to mental health. However,
there was no significant direct effect of social support on
mental health, independent of other variables. Thus, we
conclude that perceived social support, or lack thereof, acts
as a conduit for part of the effect of personality on stress
and mental health. Importantly, it has been found (Redinbaugh et al., 1995) that depression was related to social
support and remained stable over a 3-year period among
caregivers. Thus, it is important to examine what aspects of
social support are related to depression, as any intervention
that could ameliorate depression would have a large impact
on caregivers' lives.
Effects of Personality on Physical Health
Personality did not directly affect self-ratings of physical
health in this study. This is relevant because sometimes it is
argued that neuroticism "contaminates" health ratings by artificially inflating symptom reports (Watson & Pennebaker,
1989). Personality was most influential on physical health
via an indirect path through social support, stress, and mental health. Over time, the health consequences of this indirect personality influence on physical health could be great.
There is a large and growing body of research on mechanisms linking psychological constructs such as affective
states and stress to changes in immunological functioning
(for reviews, see Cohen & Williamson, 1991; Contrada et
al., 1990). For example, depression has been shown to be related to downregulation of the immune system (e.g., Herbert
& Cohen, 1993). Research with caregivers has shown complex patterns, with some studies demonstrating lessened immunocompetence among a longitudinal study of spouse
caregivers (e.g., Kiecolt-Glaser et al., 1991), while other
studies have not found strong evidence of this (e.g., Reese et
al., 1994). At a more molar level, research with wife caregivers has found depression to predict declines in health
over a 6-month period (Pruchno et al., 1990). The results of
this study suggest that inclusion of caregivers' propensity to
experience negative affect (neuroticism) and outlook on the
future (optimism) would add a lot to our understanding of
variability in mental and physical health outcomes.
AD Caregivers Compared with PD Caregivers
To advance knowledge in the broad area of caregiving,
we must begin to define our samples more cleanly and take
a comparative approach. Clearly, AD spouse caregivers had
worse mental health than PD spouse caregivers. The significant direct path from disease group to mental health
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HOOKERETAL
indicates that AD caregivers were more depressed, more
anxious, and had lower psychological well-being than PD
caregivers, even controlling for variables of stress, social
support, and personality. While many studies have confirmed that caregivers are at risk for poor mental health
(e.g., Baumgarten, 1989; Schulz et al., 1990; Schulz &
Williamson, 1994; Wright et al., 1993), this study strengthens the more specific conclusion that being an AD spouse
caregiver puts one at excess risk for poor mental health
compared with another spouse caregiving group. For example, in this study the average CES-D score for the AD caregivers was 15.1 (for PD caregivers it was 9.8); yet most
older adults score between 8 and 9 on the CES-D scale,
while a score of 16 or higher indicates that one may be at
risk for depression (Schulz et al., 1990). Thus, many of the
AD caregivers in this study did have scores indicating that
they may have been depressed.
Using dementia caregivers provided a sample that is
universally viewed as undergoing severe chronic stress
(George & Gwyther, 1986; Mace & Rabins, 1981; Zarit,
Orr, & Zarit, 1985), and spouses may be a particularly vulnerable subgroup of dementia caregivers because of their
own physical frailties, loss of social support, and lower
well-being compared with other caregivers (e.g., Cohen et
al., 1993; Hoyert & Seltzer, 1992). In fact, spouse caregivers of dementia patients have been used as prototypic
samples of people undergoing daily chronic stress in studies of immune system functioning (e.g., Kiecolt-Glaser et
al., 1991) and cardiovascular response (e.g., Uchino,
Kiecolt-Glaser, & Cacioppo, 1992, 1994). We chose spouse
caregivers of dementia patients as one of our caregiving
groups precisely because an understanding of the potential
for negative health effects due to caregiving would be maximized with this group. Thus, it was surprising that AD caregivers actually reported better physical health than PD caregivers once the influence of other variables was controlled
for statistically. While research shows equivocal results for
physical health outcomes for caregivers (see reviews by
Schulz et al., 1990; Wright et al., 1993), few studies have
directly compared different caregiving groups. Our post hoc
explanation for this unexpected finding is that AD caregivers who are in poor physical health themselves may be
more likely than PD caregivers to institutionalize their
spouses and thus would not be included in our sample of
community caregivers. Health of AD caregivers is related to
risk of institutionalization of the care recipient (Cohen et
al., 1993).
processes that guide thoughts and behaviors of individual
caregivers. The results presented here are preliminary because only two personality variables were examined, albeit
important ones for understanding health outcomes. Neuroticism, or the propensity to experience negative emotions,
and optimism, an approach to the world that emphasizes
hope for the future and an expectation that good things will
happen, were clearly related to how caregivers perceived
stress, social support, and mental health.
The sample in this study was a strategic one, necessary
for comparison purposes, which limits generalizability. Additionally, the self-selected nature of these volunteer samples makes it difficult to generalize to the population of AD
and PD caregivers. In particular we would have preferred
having samples that were roughly equivalent in terms of
length of caregiving. For example, it may be that PD caregivers had better mental health because they had more time
to adapt to their caregiving role. However, onset of caregiving is a difficult variable to measure cleanly because of differences in self-definitions of caregiving, differences in timing of health care-seeking for the ill spouse, and differences
in diagnostic procedures across health care providers.
Including both AD and PD spouse caregivers in the study
allowed for comparisons of outcomes linked to caregiving
for someone with cognitive impairment versus physical impairment. While it was useful, in this initial study, to have
both groups be caregivers for illnesses that are chronic, degenerative, late-life diseases with a relatively long time
course from initial diagnosis to end-stage, future researchers may want to study caregivers of spouses with diseases of a more limited time course (e.g., some types of
cancer; see Clipp & George, 1993). End-stage disease caregiving would be very different and take on a different
meaning than caregiving for someone in early and middle
stages of a disease. Caregivers in this situation may experience what Pearlin and Skaff (1996) refer to as a "developmental moratorium"—a time-out period when their own
lives are on hold. This may be most likely to happen when
caregiving has an expected imminent end.
The inferences we can make about causal direction of
personality on mental and physical health are limited by the
lack of longitudinal data. While it is possible that health
could influence personality (see Contrada et al., 1990), this
becomes less plausible for at least one of the measures used
in this study, as neuroticism has been shown to be a stable
trait (for a review of this research, see McCrae & Costa,
1990).
Limitations
To the extent that researchers have equated personality
with the five-factor trait model (or "big five"), they may be
less inclined to consider personality in their theoretical
frameworks. However, traits are a part of personality, not
the whole parcel (e.g., for a critique of the big five perspective see Block, 1995). While traits form the scaffold on
which personality is built, there are other aspects of personality that are more amenable to change and development
over a lifetime and in response to life events and transitions
(Hooker et al., 1994). It is necessary to examine the interrelationships of traits, states, and longer term self-regulatory
Future Directions
It appears that how one handles the stresses of living
with a spouse with chronic illness does indeed depend, to
some extent, on one's personality. While the results presented here build on previous work in this area (Hooker et
al., 1992), the addition of another disease group, the exploration of the role of social support appraisals, and the larger
samples that allowed for a more sophisticated analytic technique all strengthen the idea that personality represents an
important domain to examine if caregiver stress is to be
more fully understood. We should include measures of personality in our models as often as we include measures of
PERSONALITY AND CAREGIVING
stress, because personality is an integral part of the stress
process. The caregiver's personality and its contribution to
the stress process should be understood in its own right and
not partialled out of statistical analyses as a contaminating
influence or error variance.
Research needs to be conducted to determine relationship of personality to outcomes important for service
providers. It is possible that knowledge of personality characteristics could lead to more effective planning of service
use. One might predict, for example, that care recipients of
caregivers high in neuroticism and low in optimism would
be institutionalized sooner because of the weaker support
system and higher stress experienced by such a caregiver.
Practitioners might target such people for intervention
strategies such as training in effective coping skills, as previous research (Hooker et al., 1994) has found that personality is related to coping strategy use.
An important future direction for research on personality
and caregiving will be to gain a better understanding of
how people create meaning in their caregiving role. How do
people psychologically integrate caregiving into their sense
of identity? Self-discrepancies linked to the caregiving role
(mismatches between how one perceives self and how one
believes the self ideally should be or ought to be; see Higgins, 1987) represent one source for the negative affective
states that affect appraisals and alterations in immune responses (e.g., Strauman, Lemieux, & Coe, 1993). Knowledge of how caregiving is situated in the self and how it
affects one's personal goals will be necessary for understanding psychological appraisal processes and effects on
mental and physical health outcomes.
An obvious direction for future research is to determine
whether personality can prospectively predict as much of
the variance in mental and physical health as it does when
measures are taken concurrently. Longitudinal data are necessary to describe or explain "caregiving careers" or trajectories (Aneshensel et al., 1995)—the important transitions
into and out of the caregiving role—that will ultimately
provide the most complete answers about how people
maintain and protect their mental and physical health during this time in their lives.
ACKNOWLEDGMENTS
This research was supported by National Institute of Mental Health
grant R03-MH46637 awarded to the first author and by Petersen funds
from the Oregon State University Program on Gerontology.
We thank Alan Acock, Fuzhong Li, and Bob O'Brien for statistical advice and the research participants for sharing information about their lives
as caregivers. Leslie D. Frazier is now at the Department of Psychology,
Florida International University; Kim Shifren is now at the Institute of
Gerontology, University of Michigan.
Address correspondence to Dr. Karen Hooker, Program on Gerontology,
Bates Hall 219, Oregon State University, Corvallis, OR 97331. E-mail:
hookerk @ ucs.orst.edu
REFERENCES
Aldwin, C. M., Levenson, M. R., Spiro, A., & Bosse, R. (1989). Does
emotionality predict stress? Findings from the normative aging study.
Journal of Personality and Social Psychology, 56, 618-624.
Andersen, B. L., Kiecolt-Glaser, J. K., & Glaser, R. (1994). A biobehavioral model of cancer stress and disease course. American Psychologist, 49, 389-404.
P83
Aneshensel, C. S., Pearlin, L. I., Mullan, J. T., Zarit, S. H., & Whitlatch,
C. J. (1995). Profiles in caregiving: The unexpected career. San Diego,
CA: Academic Press.
Barefoot, J. C , Dahlstrom, W. C , & Williams, R. B. (1983). Hostility,
CHD incidence, and total mortality: A 25-year follow-up study of 255
physicians. Psychosomatic Medicine, 45, 59-63.
Baron, R. S., Cutrona, C. E., Hicklin, D., Russell, D. W, & Lubaroff, D. M.
(1990). Social support and immune function among spouses of cancer
patients. Journal of Personality and Social Psychology, 59, 344-352.
Barrera, M. Jr. (1981). Social support in the adjustment of pregnant adolescents: Assessment issues. In B. Gottleib (Ed.), Social networks and
social support. Beverly Hills, CA: Sage.
Baumgarten, M. (1989). The health of persons giving care to the demented
elderly: A critical review of the literature. Journal of Clinical Epidemiology^!, 1137-1148.
Bentler, P. M., & Bonett, D. G. (1980). Significance tests and goodness of
fit in the analysis of covariance structures. Psychological Bulletin, 88,
588-606.
Berkman, L. F., & Syme, S. L. (1979). Social networks, host resistance,
and mortality: A nine-year follow-up study of Alameda County residents. American Journal of Epidemiology, 109, 186-204.
Birkel, R. C. (1987). Toward a social ecology of the home-care household.
Psychology and Aging, 2, 294-301.
Birkel, R. C , & Jones, C. J. (1989). A comparison of the caregiving networks of dependent elderly individuals who are lucid and those who
are demented. The Gerontologist, 29, 114-119.
Block, J. (1995). A contrarian view of the five-factor approach to personality description. Psychological Bulletin, 117, 187-215.
Bolger, N. (1990). Coping as a personality process: A prospective study.
Journal of Personality and Social Psychology, 59, 525-537.
Bolger, N., & Schilling, E. A. (1991). Personality and the problems of everyday life: The role of neuroticism in exposure and reactivity to daily
stressors. Journal of Personality, 59, 355-386.
Bollen, K. A. (1989). Structural equations with latent variables. New
York: Wiley.
Bradburn, N. (1969). The structure of psychological well-being. Chicago:
Aldine.
Brody, E. M. (1981). "Women in the middle" and family help to older people. The Gerontologist, 21, 471-480.
Bromberger, J. T, & Matthews, K. A. (1996). A longitudinal study of the
effects of pessimism, trait anxiety, and life stress on depressive symptoms in middle-aged women. Psychology and Aging, 11, 207-213.
Buros, O. K. (1978). The eighth mental measurements year book. Highland Park, NJ: Gryhon.
Cantor, M. (1983). Strain among caregivers: A study of experience in the
United States. The Gerontologist, 23, 597-604.
Carver, C. S., & Scheier, M. F. (1991). Self-regulation and the self. In J.
Straus & G. R. Goethals (Eds.), The self: Interdisciplinary approaches
(pp. 168-207). New York: Springer-Verlag.
Caspi, A., Bern, D., & Elder, G. (1989). Continuities and consequences of
interactional styles across the life course. Journal of Personality, 57,
375^06.
Caspi, A., & Silva, P. A. (1995). Tempermental qualities at age three predict personality traits in young adulthood: Longitudinal evidence from
a birth cohort. Child Development, 66, 486-498.
Cattanach, L., & Tebes, J. K. (1991). The nature of elder impairment and
its impact on family caregivers' health and psychosocial functioning.
The Gerontologist, 31, 246-255.
Clipp, E. C , & George, L. K. (1990). Caregiver needs and patterns of social support. Journal of Gerontology: Social Sciences, 45, S102-S111.
Clipp, E. C., & George, L. K. (1993). Dementia and cancer: A comparison
of spouse caregivers. The Gerontologist, 33, 534-541.
Cohen, C. A., Gold, D. P., Shulman, K. I., Wortley, J. T., McDonald, G., &
Wargon, M. (1993). Factors determining the decision to institutionalize
dementing individuals: A prospective study. The Gerontologist, 33,
714-720.
Cohen, S., Karmarck, T, & Mermelstein, R. (1983). A global measure of
perceived stress. Journal of Health and Social Behavior, 24, 385-396.
Cohen, S., & Williamson, G. M. (1991). Stress and infectious disease in
humans. Psychological Bulletin, 109, 5-24.
Cohen, S., & Wills, T. H. (1985). Stress, social support, and the buffering
hypothesis. Psychological Bulletin, 98, 310-357.
Connell, C. M., & D'Augelli, A. R. (1990). The contribution of personality
P84
HOOKER ETAL
characteristics to the relationship between social support and perceived
physical health. Health Psychology, 9, 192-207.
Contrada, R. J., Leventhal, H., & O'Leary, A. (1990). Personality and
health. In L. A. Pervin (Ed.), Handbook of personality: Theory and research (pp. 638-669). New York: Guilford Press.
Costa, P. T., &McCrae, R. R. (1985). Hypochondriasis, neuroticism, and
aging: When are somatic complaints unfounded? American Psycholo-
gist, 40, 19-28.
Costa, P. T., & McCrae, R. R. (1989). NEO PI/FFI manual supplement.
Odessa, FL: Psychological Assessment Resources.
Cozzarelli, C. (1993). Personality and self-efficacy as predictors of coping
with abortion. Journal of Personality and Social Psychology, 65,
1224-1236.
Davies, A. R., & Ware, J. E. Jr. (1981). Measuring health perceptions in
the health insurance experiment. Santa Monica, CA: Rand.
Delwaide, P. J., & Gonce, M. (1988). Pathophysiology of Parkinson's
signs. In J. Jankovic & E. Tolosa (Eds.), Parkinson's disease and
movement disorders (pp. 59-73). Baltimore: Urban & Schwarzenberg.
Ewart, C. K., & Kolodner, K. B. (1994). Negative affect, gender, and expressive style predict elevated ambulatory blood pressure in adolescents. Journal of Personality and Social Psychology, 66, 596-605.
Festinger, L. A. (1954). A theory of social comparison processes. Human
Relations, 7, 117-140.
Folstein, M. F., Folstein, S. E., &McHugh, P. R. (1975). "Mini-mental
state": A practical method for grading the cognitive state of patients for
the clinician. Journal of Psychiatric Research, 12, 189-198.
Friedman, H. S., & Booth-Kewley, S. (1987). The "disease-prone personality": A meta-analytic view of the construct. American Psychologist,
42, 539-555.
Gatz, M., Bengtson, V. L., & Blum, M. J. (1990). Caregiving families. In J.
E. Birren & K. W. Shaie (Eds.), Handbook of the psychology of aging
(3rd ed., pp. 404-426). San Diego, CA: Academic Press.
George, L. K. (1994). Caregiver burden and well-being: An elusive distinction. The Gerontologist, 34, 6-7.
George, L. K., & Gwyther, L. P. (1986). Caregiver well-being: A multidimensional examination of family caregivers of demented adults. The
Gerontologist, 26, 253-259.
Graham, J. W., Hofer, S. M., & Piccinin, A. M. (1994). Analysis with
missing data in drug prevention research. In L. M. Collins & L. A.
Seitz (Eds.), Advances in data analysis for prevention/intervention research (pp. 13-63). (NIDA Research Monograph 142; DHHS Pub. No.
94-3599.) Washington, DC: U.S. Government Printing Office.
Haley, W. E., Levine, E., Brown, L., & Bartolucci, A. (1987). Stress
appraisal, coping and social supports as mediators of adaptational
outcome among dementia caregivers. Psychology and Aging, 2,
323-330.
Hansson, R. O., & Carpenter, B. N. (1990). Relational competence and adjustment in older adults: Implications for the demands of aging. In
M. A. P. Stephens, J. H. Crowther, S. E. Hobfoll, & D. L. Tennenbaum
(Eds.), Stress and coping in later life families (pp. 131-151). New
York: Hemisphere.
Herbert, T. B., & Cohen, S. (1993). Depression and immunity: A metaanalytic review. Psychological Bulletin, 113,472-486.
Higgins, E. T. (1987). Self-discrepancy: A theory relating self and affect.
Psychological Review, 94, 319-340.
Hollingshead, A. B. (1975). Four factor index of social status. Unpublished manuscript. Yale University, New Haven, CT.
Hooker, K., Frazier, L. D., & Monahan, D. J. (1994). Personality and coping among caregivers of spouses with dementia. The Gerontologist, 34,
386-392.
Hooker, K., Monahan, D., Shifren, K., & Hutchinson, C. (1992). Mental
and physical health of spouse caregivers: The role of personality. Psychology and Aging, 7,367-375.
House, J. S., Landis, K. R., &Umberson, D. (1988). Social relationships
and health. Science, 241, 540-544.
Hoyert, D. L., & Seltzer, M. M. (1992). Factors related to the well-being
and life activities of family caregivers. Family Relations, 41, 74-81.
Idler, E. L., & Kasl, S. (1991). Health perceptions and survival: Do global
evaluations of health status really predict mortality? Journal of Gerontology: Social Sciences, 46, S55-S65.
Jemmott, J. B. HI, & Magloire, K. (1988). Academic stress, social support,
and secretory immunoglobulin A. Journal of Personality and Social
Psychology, 55, 803-810.
Johnson, C. L., &Catalano, D. J. (1983). A longitudinal study of family
supports to impaired elderly. The Gerontologist, 23, 612-618.
Joreskog, K. G., & Sorbom, D. (1993). L1SREL 8: User's reference guide.
Chicago: Scientific Software International.
Kaplan, G., Barrell, V., & Lusky, A. (1988). Subjective state of health and
survival in elderly adults. Journal of Gerontology: Social Sciences, 43,
S114-S120.
Kiecolt-Glaser, J. K., Dura, J. R., Speicher, C. E., Trask, J., & Glaser, R.
(1991). Spousal caregivers of dementia victims: Longitudinal changes
in immunity and health. Psychosomatic Medicine, 53, 345-362.
Lakey, B. (1989). Personal and environmental antecedents of perceived social support. American Journal of Community Psychology, 17, 503-519.
Lakey, B., McCabe, K. M., Fisicaro, S. A., & Drew, J. B. (1996). Environmental and personal determinants of support perceptions: Three generalizability studies. Journal of Personality and Social Psychology, 70,
1270-1280.
Lawton, M. P., Moss, M., Fulcomer, M., & Kleban, M. H. (1982). A research and service oriented multilevel assessment instrument. Journal
of Gerontology, 37, 91-99.
Lawton, M. P., Moss, M., Kleban, M. H., Glicksman, A., & Rovine, M.
(1991). A two-factor model of caregiving appraisal and psychological
well-being. Journal of Gerontology: Psychological Sciences, 46,
P181-P189.
Lazarus, R. S. (1991). Progress on a cognitive-motivational-relational theory of emotion. American Psychologist, 46, 819-834.
Lazarus, R. S., & Folkman, S. (1984). Stress, appraisal, and coping. New
York: Springer.
Leedham, B., Meyerowitz, B. E., Muirhead, J., & Frist, W. H. (1995). Positive expectations predict health after heart transplantation. Health Psychology, 14,74-79.
Lesser, R. P., Fahn, S., Snider, S. R., Cote, L. J., Isgreen, W. P., & Barrett,
R. E. (1979). Analysis of the clinical problems in Parkinsonism and
the complications of long term levodopa therapy. Neurology, 29,
1253-1260.
Levin, B. E., & Weiner, W. J. (1987). Psychosocial aspects. In W. C.
Koller (Ed.), Handbook of Parkinson's disease (pp. 465-474). New
York: Marcel Dekker.
Levitt, E. E. (1967). The psychology of anxiety. Indianapolis: Bobbs-Merrills.
Light, J. M., Grigsby, J. S., & Bligh, M. C. (1996). Aging and heterogeneity: Genetics, social structure, and personality. The Gerontologist, 36,
165-173.
Liptzin, B., Grob, M. C , & Eisen, S. V. (1988). Family burden of demented and depressed elderly psychiatric inpatients. The Gerontolo-
gist, 28, 397^01.
Little, R. J. A., & Rubin, D. B. (1987). Statistical analysis with missing
data. New York: John Wiley & Sons.
Mace, N. L., & Rabins, P. V. (1981). The 36-hour day. Baltimore: Johns
Hopkins University Press.
Magnus, K., Diener, E., Fujita, F, & Pavot, W. (1993). Extraversion and
neuroticism as predictors of objective life events: A longitudinal study.
Journal of Personality and Social Psychology, 65, 1046-1053.
McKhann, G., Drachman, D., Folstein, M., Katzman, R., Price, D., &
Stadlan, E. M. (1984). Clinical diagnosis of Alzheimer's disease: Report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer's
disease. Neurology, 34, 939-944.
McCrae, R. R., & Costa, P. T. (1990). Personality in adulthood. New York:
Guilford Press.
Mendelsohn, G. A., Dakof, G. A., & Skaff, M. (1995). Personality change
in Parkinson's disease patients: Chronic disease and aging. Journal of
Personality, 63, 233-257.
Monahan, D. J., & Hooker, K. (1995). Health of spouse caregivers of dementia patients: The role of personality and social support. Social
Work, 40,305-314.
Muenter, M. D. (1982). Initial treatment of Parkinson's disease. Clinical
Neuropharmacology, 5 (Suppl. 1), 2-12.
Motenko, A. K. (1989). The frustrations, gratifications, and well-being of
dementia caregivers. The Gerontologist, 29, 166-172.
Muthen, B., Kaplan, D., & Hollis, M. (1987). On structural equation modeling with data that are not missing completely at random. Psycho-
metrika, 52,413-462.
Ormel, J., &Wohlfarth, T. (1991). How neuroticism, long-term difficulties, and life situation change influence psychological distress: A Ion-
PERSONALITY AND CAREGIVING
gitudinal model. Journal of Personality and Social Psychology, 60,
744-755.
Pearlin, L. I., & Skaff, M. M. (1996). Stress and the life course: A paradigmatic alliance. The Gerontologist, 36, 239-247.
Poulshock, S. W., & Deimling, G. T. (1984). Families caring for elders in
residence: Issues in the measurement of burden. Journal of Gerontology, 39, 230-239.
Pruchno, R. A., Kleban, M. H., Michaels, J. E., & Dempsey, N. P. (1990).
Mental and physical health of caregiving spouses: Development of a
causal model. Journal of Gerontology, 45, 192-199.
Pruchno, R. A., & Potashnik, S. L. (1989). Caregiving spouses: Physical
and mental health in perspective. Journal of the American Geriatrics
Society, 37, 697-705.
Pruchno, R. A., & Resch, N. L. (1989). Mental health of caregiving
spouses: Coping as mediator, moderator, or main effect? Psychology
and Aging, 4, 454—463.
Rabins, P. V., Fitting, M. D., Eastham, J., & Zabora, J. (1990). Emotional
adaptation over time in caregivers for chronically ill elderly people.
Age and Ageing, 19, 185-190.
Radloff, L. S. (1977). The CES-D Scale: A self-report depression scale for
research in the general population. Applied Psychological Measurement, 7,385^01.
Redinbaugh, E. M., MacCallum, R. C , & Kiecolt-Glaser, J. K. (1995). Recurrent syndromal depression in caregivers. Psychology and Aging, 10,
358-368.
Reker, G. T., & Wong, P. T. (1985). Personal optimism, physical and mental health: The triumph of successful aging. In J. E. Birren & J. Livingston (Eds.), Cognition, stress, and aging (pp. 134-173). Englewood
Cliffs, NJ: Prentice-Hall.
Reese, D. R., Gross, A. M., Smalley, D. L., & Messer, S. C. (1994). Caregivers of Alzheimer's disease and stroke patients: Immunological and
psychological considerations. The Gerontologist, 34, 534-540.
Rodin, J., & Salovey, P. (1989). Health psychology. Annual Review of Psychology, 40, 533-579.
Rubin, D. B. (1987). Multiple imputation for nonresponse in surveys. New
York: Wiley.
Scarr, S., & McCartney, K. (1983). How people make their own environments: A theory of genotype-environment effects. Child Development,
54,424-435.
Scheier, M. F., & Carver, C. S. (1985). Optimism, coping, and health: Assessment and implications of generalized outcome expectancies.
Health Psychology, 4, 219-247.
Scheier, M. F., Carver, C. S., & Bridges, M. W. (1994). Distinguishing
optimism from neuroticism (and trait anxiety, self-mastery, and selfesteem): A reevaluation of the Life Orientation Test. Journal of
Personality and Social Psychology, 67, 1063-1078.
Scheier, M. F., Matthews, K. A., Owens, J. F., Magovern, G. J., Lefebvre,
R. C , Abbott, R. A., & Carver, C. S. (1989). Dispositional optimism
and recovery from coronary artery bypass surgery: The beneficial effects on physical and psychological well-being. Journal of Personality
and Social Psychology, 57, 1024-1040.
Schneirla, T. C. (1957). The concept of development in comparative psychology. In D. B. Harris (Ed.), The concept of development: An issue
in the study of human behavior (pp. 78-108). Minneapolis: University
of Minnesota Press.
Schulz, R., Visintainer, P., & Williamson, G. M. (1990). Psychiatric and
physical morbidity effects of caregiving. Journal of Gerontology: Psychological Sciences, 45, P181-P191.
Schulz, R., & Williamson, G. M. (1994). Health effects of caregiving:
Prevalence of mental and physical illness in Alzheimer's caregivers. In
E. Light, G. Niederehe, & B. D. Lebowitz (Eds.), Stress effects on family caregivers of Alzheimer's patients (pp. 38-63). New York: Springer.
Shifren, K., & Hooker, K. (1995a). Stability and change in optimism: A
study among spouse caregivers. Experimental Aging Research, 21,
59-76.
Shifren, K., & Hooker, K. (1995b). Daily measurements of anxiety and affect: A study among spouse caregivers. International Journal of Behavioral Development, 18, 595-607.
Siegler, I. C. (1989). Developmental health psychology. In M. Storandt &
G. R. VandenBos (Eds.), The adult years: Continuity and change (pp.
119-142). Washington, DC: American Psychological Association.
Spielberger, C. D. (1980). Manual for the State-Trait Anxiety Inventory.
Palo Alto, CA: Consulting Psychologists Press.
P85
Stern, M. B. (1988). The clinical characteristics of Parkinson's disease and
Parkinsonian syndromes: Diagnosis and assessment. In M. B. Stern &
H. I. Hurtig (Eds.) The comprehensive management of Parkinson's disease (pp. 3-50). New York: PMA Publishing Corp.
Strauman, T. J., Lemieux, A. M., & Coe, C. L. (1993). Self-discrepancy
and natural killer cell activity: Immunological consequences of negative self-evaluation. Journal of Personality and Social Psychology, 64,
1042-1052.
Suh, E., Diener, E., & Fujita, F. (1996). Events and subjective well-being:
Only recent events matter. Journal of Personality and Social Psychology, 70, 1091-1102.
Suls, J., & Mullen, B. (1982). From the cradle to the grave: Comparison
and self-evaluation across the life-span. In J. Suls (Ed.), Psychological
perspectives on the self (Vol. 1; pp. 97-125). Hillsdale, NJ: Lawrence
Erlbaum.
Taylor, S. E., & Lobel, M. (1989). Social comparison activity under threat:
Downward evaluation and upward contacts. Psychological Review, 96,
569-575.
Uchino, B. N., Kiecolt-Glaser, J. K, & Cacioppo, J. T. (1992). Age-related
changes in cardiovascular response as a function of a chronic stressor
and social support. Journal of Personality and Social Psychology, 63,
839-846.
Uchino, B. N., Kiecolt-Glaser, J. K., & Cacioppo, J. T. (1994). Construals
of preillness relationship quality predict cardiovascular response in
family caregivers of Alzheimer's disease victims. Psychology and
Aging, 9, 113-120.
Usala, P., & Hertzog, C. (1990, August). Age-equivalence of state anxiety
factor structure. Paper presented at the 98th Annual Convention of the
American Psychological Association, Boston, MA.
Vaux, A., Phillips, J., Holly, L., Thomson, B., Williams, D., & Stewart, D.
(1986). The social support appraisals (SS-A) scale: Studies of reliability and validity. American Journal of Community Psychology, 14,
195-219.
Vernon, G. M., & Stern, M. B. (1988). The comprehensive approach to
Parkinson's disease. In M. B. Stern & H. I. Hurtig (Eds.), The comprehensive management of Parkinson's disease (pp. 103-115). New York:
PMA Publishing Corp.
Vitaliano, P. P., Russo, J., Young, H. M., Teri, L., & Maiuro, R. D. (1991).
Predictors of burden in spouse caregivers of individuals with Alzheimer's disease. Psychology and Aging, 6, 392-402.
Vitaliano, P. P., Russo, J., Scanlan, J. M., & Greeno, K. (1996). Weight
changes in caregivers of Alzheimer's care recipients: Psychobehavioral
predictors. Psychology and Aging, 11, 155-163.
Vitaliano, P. P., Scanlan, J. M., Frenz, C , & Fujimoto, W. (1996). Insulin
and glucose: Relationships with hassles, anger and hostility in nondiabetic older adults. Psychosomatic Medicine, 58,489-499.
Walker, A. J., Acock, A. C , Bowman, S. R., & Li, F. (1996). Amount of
care given and caregiving satisfaction: A latent growth curve analysis.
Journal of Gerontology: Psychological Sciences, 5IB, P130-P142.
Watson, D., & Pennebaker, J. W. (1989). Health complaints, stress, and
negative distress: Exploring the central role of negative affectivity.
Psychological Review, 96, 234-254.
Wethington, E., & Kessler, R. C. (1986). Perceived support, received support, and adjustment to stressful life events. Journal of Health and Social Behavior, 27, 78-89.
Wills, T. A. (1981). Downward comparison principles in social psychology. Psychological Bulletin, 90, 245-271.
Wood, J. V. (1989). Theory and research concerning social comparisons of
personal attributes. Psychological Bulletin, 106, 231-248.
Wright, L. K., Clipp, E. C , & George, L. K. (1993). Health consequences of
caregiver stress. Medicine, Exercise, Nutrition, and Health, 2, 181-195.
Yu, E., Liu, W. T, Wang, Z., Levy, P. S., Katzman, R., Zhang, M., Qu, G.,
& Chen, F. (1993). Caregivers of the cognitively impaired and the disabled in Shanghai, China. In S. H. Zarit, L. I. Pearlin, & K. W. Schaie
(Eds.), Caregiving systems: Formal and informal helpers (pp. 5-30).
Hillsdale, NJ: Lawrence Erlbaum.
Zarit, S. H., Orr, N. K, & Zarit, J. H. (1985). The hidden victims of Alzheimer's disease: Families under stress. New York: New York University.
Zarit, S., Reever, K., & Bach-Peterson, J. (1980). Relatives of the impaired
elderly: Correlates of feelings of burden. The Gerontologist, 20,649-655.
Received November 14, 1996
Accepted April 3, 1997