European Journal of Neurology 2012, 19: 666–671
doi:10.1111/j.1468-1331.2011.03635.x
CME ARTICLE
How subjective are subjective language complaints
I. P. Martinsa, I. Maresa and P. A. Stilwellb
a
Department of Clinical Neurosciences (UNIC), Instituto de Medicina Molecular, Lisbon Faculty of Medicine (IMM), Portugal; and
b
Faculty of Medicine, University of Bristol, UK
See editorial by Cappa, on page 665.
Keywords:
ageing, cognitive complaints, subjective cognitive symptoms, language
complaints
Received 23 September 2011
Accepted 8 November 2011
Background and purpose: Subjective language complaints (SLC) are common during
ageing but have not been investigated in detail. We aim to determine their association
with demographic and clinical variables and objective cognitive performance.
Methods: A sample of 479 individuals aged 50 years or above (average
66 ± 9.1 years), followed in primary care, with no history of brain disorder were
asked two questions concerning SLC, fulfilled a depression scale and undertook a
battery of cognitive tests. Response to questions regarding proper name retrieval
(PNR) and word finding difficulties (WFD) was studied and their contribution to each
measure of the battery calculated by repeated linear regression analysis, adjusting for
age, sex, education, living alone and depressive symptoms.
Results: Word finding difficulties (47.6%) were more frequently reported than
problematic PNR (10.9%). Both were more common in women, in subjects with
depressive symptoms and in those living alone, but were unrelated with age or education. Both symptoms contributed significantly to the variance in tests of semantic
fluency and episodic memory. PNR was also associated with immediate phonological
memory.
Conclusions: Subjective language complaints are especially common amongst individuals living alone and/or with depressive symptoms. They are associated with a
worse cognitive performance in some memory and language-executive tests. Further
studies are needed to understand their predictive value for cognitive decline.
Introduction
Language is essential for the adequate communication
of thoughts, intentions, wishes and the success of social
interaction. Failures in language expression usually
cause embarrassment and may hamper interpersonal
relationships.
Although language is relatively resistant to ageing [1],
there is evidence that word retrieval ability declines with
age [2] despite the fact that elderly subjects are able to
maintain or improve their vocabulary and knowledge of
word meaning [2]. Such language complaints are often
experienced as a tip of the tongue (TOT) phenomenon,
Correspondence: I. P. Martins, Language Research Laboratory,
Department of Neurosciences, Lisbon Faculty of Medicine, Instituto
de Medicina Molecular, Hospital de Sta Maria 1600 Lisboa, Portugal
(Telefax: 351 217 934 480; e-mail: [email protected]).
This is a Continuing Medical Education article, and can be found with
corresponding questions on the Internet at http://www.efns.org/EFNS
Continuing-Medical-Education-online.301.0.html. Certificates for
correctly answering the questions will be issued by the EFNS.
666
a state during which one is temporarily unable to produce a word despite knowing it and being able to partially access its visual form [3]. TOTs become more
frequent as one ages [4] and seem to be particularly
common for proper names [5] because these are pure
referential and arbitrary expressions, without inherent
semantic value [6].
In some people, difficulties with language production
may become a source of concern and a reason to seek
medical advice. Yet, the relation between subjective
language complaints (SLC) and objective cognitive
performance is not clear. Therefore, it is difficult for
physicians to reassure patients who present with those
complaints that their symptoms do not reflect objective
cognitive impairment, given the hypothesis that they
could signal the onset of a degenerative disease, such as
AlzheimerÕs disease.
In contrast with that lack of knowledge, there is a
large amount of research about subjective memory
complaints. This discrepancy may arise from the early
involvement of episodic memory in the most common
degenerative brain diseases and also the incorporation
2012 The Author(s)
European Journal of Neurology 2012 EFNS
How subjective are subjective language complaints
of memory complaints in the diagnostic criteria for mild
cognitive impairment (MCI) [7–9]. Cross-sectional
studies examining whether peopleÕs memory complaints
correlate with current cognitive performance have
produced mixed results. Nonetheless, a systematic review of such studies [10] and a recent meta-analysis [11]
have shown an association between memory complaints
and memory impairment, as well as a high specificity,
for both MCI and dementia.
Longitudinal studies have also examined the association between current complaints and future cognitive
decline. They have indicated that memory complaints,
even in the absence of objective impairment on neuropsychological examination, can be an early marker of
future cognitive deterioration [12,13] and possible progression to dementia [14]. Altogether, these data suggest
that subjective memory complaints in otherwise normal
older adults could be realistic self-observations of the
initial stages of cognitive decline.
Other cognitive complaints have received much less
attention despite the evidence that ageing is also associated with a decline in executive skills and language [1].
Indeed, most studies evaluating cognitive complaints
have analysed total scores on subjective failures questionnaires, rather than focusing on individual complaints [13,15,16]. Notable exceptions that looked at
SLC are the study by Fischer et al. [17], who showed that
depressive symptoms in old age are strongly associated
with increased language complaints, and Dave [18], who
suggested that complaints about language, as opposed
to memory or attention, predict future language decline.
The purpose of this study is as follows: (i) to estimate
the frequency of SLC in a sample of adults observed in
primary care and its relation with socio-demographic
and clinical variables and (ii) to determine whether
there is an association between SLC and objective
performance in neuropsychological tests.
Method
Study design and setting
This study is part of a larger prospective longitudinal
project [19] aimed to evaluate the cognitive profiles in
ageing in a cohort of adults, followed in public primary
care centres, without known brain disease. A detailed
description of the project, population and method,
including the cognitive battery used, has been reported
elsewhere [19].
General practitioners (GPs) screened 544 volunteers,
aged 50 or above, who were not suspected of dementia
and were independent in daily living activities. Participants were further screened by the Mini-Mental State
Examination (MMSE) [20] and were included if they
667
had a score above education-adjusted cut-off points (i.e.
22 for individuals with <12 years of education and 27
for those with 12 or more years of education) [21].
The study protocol was approved by the Ethics
Committee of Lisbon Faculty of Medicine, by the
Institutional Board of participating Regional Health
Centres and by the National Committee for Data
Protection. Informed consent was obtained for all
participants.
Procedures
Clinical data were provided by the participantsÕ GP,
namely the presence of vascular risk factors (i.e.
hypertension, diabetes and hypercholesterolaemia). All
participants were evaluated individually by a licensed
psychologist. Socio-demographic information was collected, including age, sex, number of years of education
and household company. This was followed by a cognitive evaluation and questionnaires for depression and
cognitive complaints. Evaluation took place in a private
office in the health centres.
Subjective language complaints were assessed by two
questions of the Subjective Memory Complaints Scale
[22]. One of them was directed to difficulties in Ôproper
name retrievalÕ (PNR), ÔDo you ever forget names of
family members or friends?Õ, whereas the second referred to Ôword finding difficultiesÕ (WFD), ÔDo you
ever have difficulties in finding particular words?Õ. The
former had four possible answers (0 – No; 1 – Yes, but
no problem; 2 – Yes, problem; 3 – Yes, serious problem), whilst the latter had two (0 – No; 1 – Yes). To
make answers comparable and avoid scaling bias,
PNR responses were dichotomised into absence (score
0 or 1) or presence (score 2 or 3) of problematic
complaints. This division was suggested by Schmand
et al. [22] and was adopted, given that these symptoms
were not spontaneously reported and we were trying to
differentiate clinically relevant complaints from minor
ones.
Depressive symptoms were evaluated by the 15-item
version of the GDS [23]. Subjects were divided as with
(GDS > 5) or without (GDS < 6) significant depressive symptoms according to a recognised cut-off point
[24]. Participants were also classified as living alone or
with household company.
The original cognitive battery included 28 tests or
measures directed to different cognitive domains [19].
For this study, we selected the 15 most frequently used
measures to assess language, episodic memory and
executive functions. Language testing included vocabulary [25], verbal fluency (animal and food categories
and p-phonemic fluency) [26], naming famous faces [27]
and digit span forward) [26]. Episodic memory was
2012 The Author(s)
European Journal of Neurology 2012 EFNS European Journal of Neurology
668
I. P. Martins, I. Mares and P. A. Stilwell
evaluated by the learning trials and long delay free recall of the nine-item version of California Verbal
Learning Test (CVLT-9) [28] and by the memory for
faces and immediate visual reproduction subtests of the
WMS-III [26]. Attention and executive functions were
assessed by the Symbol Search [29], Trail B [30], a
Stroop [31] task of inhibitory control, digit span backward
[26] and the Wechsler Abbreviated Scale of Intelligence
(WASI) Matrix Reasoning [25] tests.
Statistical analysis
Frequencies were calculated for WFD and PNR complaints. Chi-square analysis and Spearman rank correlations were used to examine the association between
demographic and clinical variables and SLC. Repeated
multivariate linear regression analysis was used to
determine whether there was an association between
SLC and objective test performance, in which the
dependent variable was the score obtained on each of
the cognitive tests and the explanatory variables were
age, number of years of education, sex, GDS score,
household company and WFD and PNR complaints.
The last four variables were entered in the regression
dichotomised as explained earlier. Comparisons were
two tailed and considered significant with P < 0.05.
Results
Participants had a mean age of 66 years (±9.1; range
50–95), and the majority were women (60.3%). Mean
educational level was 7.7 years (±4.1). Of all 479 participants, 478 completed the GDS and SLC questions,
of whom 24% had a GDS score above 5% and 14.4%
lived alone. Mean MMSE scores, SD and range by
education groups were as follows: 26.3 + 2.2 (22–30)
for 0–3 years of formal education; 27.9 + 1.7 (22–30)
for 4–6 years of education; and 29.1 + 1.1 (25–30) for
seven or more years of education.
Half of the subjects (49.6%) complained of either
type of SLC. Only 10.9% reported problematic PNR
and 47.6% reported WFD. Neither type of language
complaint correlated with age (rS = )0.028 and 0.017,
respectively) nor with the number of years of education
(rS = 0.028 and )0.05, respectively). Both were more
common in women, in subjects with depressive symptoms and in those living alone (Table 1). None of the
SLC correlated with cardiovascular risk factors. The
two types of SLC had a mild correlation with each
other (rS = 0.304; P < 0.001), considering all four
possible answers to PNR.
On the linear regression analysis, SLC correlated
with objective performance on some cognitive tests,
Table 1 Association between type of complaint and sex, household
company and depressive symptoms
Type of complaint
Proper names
% with
complaints
Sex
Male
7.0
Female
13.1
Household company
Alone
17.6
With company
9.7
GDS
GDS > 5
20.0
GDS £ 5
8.0
Word finding
v2
P
% with
complaints
v2
P
4.2
0.05
35.5
54.6
16.1
0.01
4.0
0.04
60.8
45.3
6.0
0.01
12.9
0.01
72.2
39.9
36.4
0.01
controlling for age, sex, education, depression and
household company (Table 2).
Proper name retrieval had a significant correlation
with the food and animal category fluency tests
(P = 0.02 and P = 0.03, respectively), digit span forward (P < 0.001), CVLT-9 1–5 (P = 0.03) and
immediate visual memory test (P = 0.03). WFD correlated with fewer tests, namely with food category
fluency (P = 0.03) and CVLT-9 1–5 score (P = 0.03).
Living alone had a marginal effect on objective performance on the food fluency test (B = )1.14;
b = )0.09; t = )1.96; P = 0.051). The regression
model was supported in all tests and measures, and the
adjusted R2 accounted for between 17.2% (CVLT
delayed recall) and 44% (WASI Vocabulary) of the
variance in test performance.
Discussion
This study showed that SLC are common amongst
adult and elderly individuals attending primary care
and that they bear some relation with objective cognitive performance.
In what concerns symptom frequency, the values
found in our study were inside the range of subjective
cognitive complaints cited in the literature (25–50%) in
community studies [10]. However, WFD were more
reported than PNR which was not expected because
proper names are known to be more difficult to retrieve
than common names [6]. Yet, these differences could
also be attributed to the fact that the two questions used
a different range of possible answers. In addition, Ôword
findingÕ question did not specify the type of words Ôin
failureÕ allowing for a broad interpretation, which
might include proper names. Other studies performed
with the same questionnaire yielded identical results
2012 The Author(s)
European Journal of Neurology 2012 EFNS European Journal of Neurology
How subjective are subjective language complaints
669
Table 2 Association between subjective language complaints and objective cognitive performance in neuropsychological tests
Proper names
Tests
Language
Category fluency (Food)
Category fluency (Animals)
Phonemic fluency (Letter ÔpÕ)
Famous faces test
WASI vocabulary
Direct digit span
Episodic memory
CVLT (1–5)
CVLT (20-min interval)
Faces (WMS-III)
Immediate visual memory (WMS-II)
Executive and attention functions
Stroop (interference)
Invert digit span
Trail B
WASI matrix
Symbol search
Word finding
B
b
T
P
B
b
T
P
)1.56
)1.39
)0.54
)1.31
0.65
)0.51
)0.10
)0.90
)0.04
)0.04
0.01
)0.14
)2.36
)2.19
)0.89
)0.10
0.40
)3.25
0.02
0.03
n.s.
n.s.
n.s.
0.00
)0.95
)0.50
)0.19
)0.79
)0.70
)0.69
)0.10
)0.53
)0.02
)0.04
)0.03
)0.03
)2.23
)1.24
)0.48
)1.00
)0.68
)0.68
0.03
n.s.
n.s.
n.s.
n.s.
n.s.
)1.56
)0.16
)0.43
)5.36
)0.09
)0.03
)0.05
)0.08
)2.16
)0.63
)1.09
)2.14
0.03
n.s.
n.s.
0.03
)1.01
)0.25
)0.39
)0.98
)0.10
)0.07
)0.04
)0.02
)2.18
)1.55
)0.91
)0.62
0.03
n.s.
n.s.
n.s.
)0.33
)0.21
8.77
0.30
0.05
)0.01
)0.06
0.03
0.01
0.00
)0.26
)1.34
0.86
0.35
0.05
n.s.
n.s.
n.s.
n.s.
n.s.
)0.56
0.05
1.93
0.62
)0.68
)0.03
0.02
0.01
0.05
)0.05
)0.69
0.49
0.30
1.14
)1.21
n.s.
n.s.
n.s.
n.s.
n.s.
Repeated multiple linear regression analysis controlling for age, sex, living alone, education and depression (cut-off 5) demonstrated that PNR and
WFD explained the variance of some language and memory tests. CVLT, California Verbal Learning Test.
[22,32]. Thus, the frequency of complaints can be due to
differences in the criteria used for sampling and
assessing complaints. The two SLCs had a weak correlation with each other, suggesting that they do not
represent exactly the same type of difficulty.
Cognitive complaints are known to be more prevalent
in women, in advancing age, and in subjects with subcortical white matter changes [33,34], yet we did not find
any relation with age nor with vascular risk factors. This
was also found in a sample with a much wider age range
(from 18 to 92 years) using the same questionnaire [32].
According to that study, language complaints are less
related with age than memory complaints.
On the other hand, SLC were positively correlated
with depressive symptoms and with living alone.
Depression has been consistently associated with the
total number of cognitive complaints [15,35]. They may
result from a loss of self-esteem and increased focus on
negative aspects of oneÕs life or abilities [36] because of
the mood disturbance or depression-associated executive and memory decline [37]. Thus, it is important to
screen for depression in patients presenting with language complaints.
It was interesting to find that SLC were significantly
more common in subjects living alone, a variable that
was also marginally associated with a fluency test (food
category). This might eventually suggest that maintaining regular conversations decreases language difficulties, which is in agreement with other findings about
cognitive performance [38]. Indeed, social interactions
can be viewed as natural forms of cognitive stimulation,
whereas living alone would represent a situation of
relative cognitive deprivation.
Concerning objective cognitive performance, SLC
were not only associated with tests that tackle language
functions but also with a worse performance in learning
and attention tasks. It is worth noticing that some tests
like the CVLT 1–5 and digit spans are verbal tasks and
may decrease with language difficulties. Semantic fluency tests were consistently associated with both SLC.
A study performed in subjects submitted to temporal
lobectomy [39] also found that word finding complaints
correlated with semantic fluency but not with a Naming
Test, nor with the Controlled Oral Word Association or
other neuropsychological variables. In fact, semantic
fluency tasks, contrarily to confrontation naming, not
only require an access to semantic memory but also
impose demands upon effortful self-initiated retrieval
[40], which is more similar to spontaneous conversation. Compared to phonemic fluency tasks, those tests
seem to be more dependent upon the integrity of
semantic memory rather than on executive processes
[41]. Furthermore, these tests are predictive of dementia
in people with MCI [42]. Unexpectedly, there was no
association between PNR and the ability to name famous faces, indicating that SLC may not have a strict
relation with performance in the exact category that is
the source of complaint.
Although depressive symptoms could be fuelling
complaints and were indeed correlated with both SLC,
2012 The Author(s)
European Journal of Neurology 2012 EFNS European Journal of Neurology
670
I. P. Martins, I. Mares and P. A. Stilwell
the association between symptoms and cognitive performance persisted after controlling for depression. It
could be argued that these findings are related to a lack
of sensibility of the test used to measure depression, but
GDS was earlier found to have an overall sensitivity
and specificity of 0.97 and 0.95 in a large geriatric
community-living sample [43].
We acknowledge a number of limitations to this
study. First, the two questions had a different scoring
system, and as the question concerning WFD only had
two possible answers, problematic complaints could not
be defined in detail. Secondly, we only analysed two
possible types of language complaints, and there may be
more interesting and specific questions to analyse
regarding language. Thirdly, the effect of depression on
cognitive performance cannot be completely excluded, a
limitation we tried to overcome by controlling for this
variable in the regression analysis. Finally, because of
the poor sensitivity of the MMSE to diagnose MCI or
early stages of dementia, we cannot guarantee that all
participants were cognitively intact and there may be a
small number of participants with MCI or mild
dementia in this sample. Nonetheless, some studies have
shown that the use of MMSE to diagnose dementia in
primary care has a negative predictive value of 95.7%,
making it an acceptable tool to rule out dementia in this
type of setting [44]. The low MMSE cut-off used is
identical to the values established for populations with
low levels of literacy [45]. Given these limitations and
the population studied, results can only be generalised
to adults without clinically evident dementia or known
brain disease.
Despite these limitations, this study is original, suggesting that (i) both SLC, WFD and PNR difficulties
contributed to the variance in performance in some
language and memory tests, independently of concurrent depressive symptoms, and (ii) SLC and cognitive
performance are related with living alone, an association that has not been made before, suggesting that
verbal interaction amongst ageing individuals might
possibly be a modulator of cognitive awareness and
performance.
If these language findings are replicable, researchers
and clinicians would benefit from asking older adults
about perceived language decline. Further research is
needed to investigate whether the endorsement of language complaints is associated with later decline.
Acknowledgements
The authors thank Fundação Calouste Gulbenkian for
funding the present study (Project 0488) and are indebted to all participants, GPs and Health Centres
Directors who collaborated in this study.
Disclosure of conflict of interest
The authors declare no financial or other conflict of
interests.
References
1. Park DC, Reuter-Lorenz P. The adaptive brain: aging and
neurocognitive scaffolding. Annu Rev Psychol 2009; 60:
173–196.
2. Burke DM, Shafto MA. Aging and language production.
Curr Dir Psychol Sci 2004; 13: 21–24.
3. Shafto MA, Burke DM, Stamatakis EA, Tam PP, Tyler
LK. On the tip-of-the-tongue: neural correlates of increased word-finding failures in normal aging. J Cogn
Neurosci 2007; 19: 2060–2070.
4. Heine MK, Ober BA, Shenaut GK. Naturally occurring
and experimentally induced tip-of-the-tongue experiences
in three adult age groups. Psychol Aging 1999; 14: 445–
457.
5. Evrard M. Ageing and lexical access to common and
proper names in picture naming. Brain Lang 2002; 81:
174–179.
6. Semenza C. Retrieval pathways for common and proper
names. Cortex 2006; 42: 884–891.
7. Portet F, Ousset PJ, Visser PJ, et al. Mild cognitive
impairment (MCI) in medical practice: a critical review of
the concept and new diagnostic procedure. Report of the
MCI Working Group of the European Consortium on
AlzheimerÕs Disease. J Neurol Neurosurg Psychiatry 2006;
77: 714–718.
8. Petersen RC, Smith GE, Waring SC, Ivnik RJ, Tangalos
EG, Kokmen E. Mild cognitive impairment: clinical characterization and outcome. Arch Neurol 1999; 56: 303–308.
9. Albert MS, DeKosky ST, Dickson D, et al. The diagnosis
of mild cognitive impairment due to AlzheimerÕs disease:
recommendations from the National Institute on AgingAlzheimerÕs Association workgroups on diagnostic
guidelines for AlzheimerÕs disease. Alzheimers Dement
2011; 7: 270–279.
10. Jonker C, Geerlings MI, Schmand B. Are memory complaints predictive for dementia? A review of clinical and
population-based studies. Int J Geriatr Psychiatry 2000;
15: 983–991.
11. Mitchell AJ. The clinical significance of subjective memory complaints in the diagnosis of mild cognitive impairment and dementia: a meta-analysis. Int J Geriatr
Psychiatry 2008; 23: 1191–1202.
12. Verdelho A, Madureira S, Moleiro C, et al. Self-perceived
memory complaints predict progression to Alzheimer
disease. The LADIS study. J Alzheimers Dis 2011; 26: 1–8.
13. Hohman TJ, Beason-Held LL, Lamar M, Resnick SM.
Subjective cognitive complaints and longitudinal changes
in memory and brain function. Neuropsychology 2011; 25:
125–130.
14. Jungwirth S, Zehetmayer S, Weissgram S, Weber G, Tragl
KH, Fischer P. Do subjective memory complaints predict
senile Alzheimer dementia? Wien Med Wochenschr 2008;
158: 71–77.
15. Rouch I, Anterion CT, Dauphinot V, et al. Cognitive
complaints, neuropsychological performance and affective
disorders in elderly community residents. Disabil Rehabil
2008; 30: 1794–1802.
2012 The Author(s)
European Journal of Neurology 2012 EFNS European Journal of Neurology
How subjective are subjective language complaints
16. Westoby CJ, Mallen CD, Thomas E. Cognitive complaints in a general population of older adults: prevalence,
association with pain and the influence of concurrent
affective disorders. Eur J Pain 2009; 13: 970–976.
17. Fischer C, Schweizer TA, Atkins JH, et al. Neurocognitive profiles in older adults with and without major
depression. Int J Geriatr Psychiatry 2008; 23: 851–856.
18. Dave JB. Accuracy of Subjective Cognitive Complaints in a
Longitudinal Context: The Effect of Depression and
Dementia Status. [Phd Thesis]. US: Proquest, Umi Dissertation Publishing, 2009.
19. Martins IP, Maruta C, Silva C, et al. The effect of education on age related changes in three cognitive domains:
a cross-sectional study in primary care. Appl Neuropsychol
In press.
20. Folstein MF, Folstein SE, McHugh PR. ‘‘Mini-mental
state’’. A practical method for grading the cognitive state of
patients for the clinician. J Psychiatr Res 1975; 12: 189–198.
21. Guerreiro M, Silva AP, Botelho MA, Leitão O, CastroCaldas A, Garcia C. Adaptação à população portuguesa
da tradução do ‘‘Mini Mental State Examination’’
(MMSE). Revista Portuguesa de Neurologia 1994; 1: 9–10.
22. Schmand B, Jonker C, Hooijer C, Lindeboom J. Subjective memory complaints may announce dementia.
Neurology 1996; 46: 121–125.
23. Yesavage JA, Brink TL, Rose TL, et al. Development and
validation of a geriatric depression screening scale: a
preliminary report. J Psychiatr Res 1983; 17: 37–49.
24. Wancata J, Alexandrowicz R, Marquart B, Weiss M,
Friedrich F. The criterion validity of the geriatric
depression scale: a systematic review. Acta Psychiatr
Scand 2006; 114: 398–410.
25. Wechsler D. Wechsler Abbreviated Scale of Intelligence
Manual. San Antonio, TX: The Psychological Corporation, 1999.
26. Wechsler D. Wechsler Memory Scale. Third Edition
Manual. San Antonio, TX: The Psychological Corporation, 1997.
27. Martins IP, Loureiro C, Rodrigues S, Dias B. Nomeação
de faces famosas: Capacidade de evocação de nomes
próprios numa amostra populacional Portuguesa. Psicologia, Educação e Cultura 2005; 9: 421–436.
28. Libon DJ, Mattson RE, Glosser G, et al. A nine—word
dementia version of the California verbal learning test.
Clin Neuropsychol 1996; 10: 237–244.
29. Wechsler D. Wechsler Adult Intelligence Scale – III. San
Antonio, TX: The Psychological Corporation, 1997.
30. Reitan R. Validity of the trail making test as an indicator
of organic brain damage. Percept Mot Skills 1958; 8: 271–
276.
31. Stroop JR. Studies of interference in serial verbal reaction.
J Exp Psychol 1935; 18: 643–662.
671
32. Ginó S, Mendes T, Maroco J, et al. Memory complaints
are frequent but qualitatively different in young and elderly healthy people. Gerontology 2010; 56: 272–277.
33. Park MH, Min JY, Min HY, Lee HJ, Lee DH, Song MS.
Subjective memory complaints and clinical characteristics
in elderly Koreans: a questionnaire survey. Int J Nurs Stud
2007; 44: 1400–1405.
34. de Groot JC, de Leeuw FE, Oudkerk M, Hofman A,
Jolles J, Breteler MM. Cerebral white matter lesions and
subjective cognitive dysfunction: the Rotterdam Scan
Study. Neurology 2001; 56: 1539–1545.
35. Slavin MJ, Brodaty H, Kochan NA, et al. Prevalence and
predictors of ‘‘subjective cognitive complaints’’ in the
Sydney Memory and Ageing Study. Am J Geriatr Psychiatry 2010; 18: 701–710.
36. Enns MW, Cox BJ. Personality dimensions and depression: review and commentary. Can J Psychiatry 1997; 42:
274–284.
37. Austin MP, Mitchell P, Goodwin GM. Cognitive deficits
in depression: possible implications for functional neuropathology. Br J Psychiatry 2001; 178: 200–206.
38. Bennett Da, Schneider JA, Tang Y, Arnold SE, Wilson
RS. The effect of social networks on the relation between
AlzheimerÕs disease pathology and level of cognitive
function in old people: a longitudinal cohort study. Lancet
Neurol 2006; 5: 406–412.
39. Hamberger M, Seidel WT. Subjective word finding complaints: unexpected relationships with visual naming and
semantic fluency. Arch Clin Neuropsychol 2001; 16: 860.
40. Henry JD, Crawford JR, Phillips LH. Verbal fluency
performance in dementia of the AlzheimerÕs type: a metaanalysis. Neuropsychologia 2004; 42: 1212–1222.
41. Henry JD, Crawford JR. A meta-analytic review of verbal
fluency performance following focal cortical lesions.
Neuropsychology 2004; 18: 284–295.
42. Chong MS, Sahadevan S. Preclinical AlzheimerÕs disease:
diagnosis and prediction. Lancet Neurol 2005; 4: 576–
579.
43. Nyunt MSZ, Fones C, Niti M, Ng T-P. Criterion-based
validity and reliability of the Geriatric Depression
Screening Scale (GDS-15) in a large validation sample of
community-living Asian older adults. Aging Ment Health
2009; 13: 376–382.
44. Mitchell AJ. A meta-analysis of the accuracy of the minimental state examination in the detection of dementia and
mild cognitive impairment. J Psychiatr Res 2009; 43: 411–
431.
45. Mungas D, Marshall SC, Weldon M, Haan M, Reed BR.
Age and education correction of mini-mental state
examination for English and Spanish-speaking elderly.
Neurology 1996; 46: 700–706.
2012 The Author(s)
European Journal of Neurology 2012 EFNS European Journal of Neurology