The natural history of late-life depression: results from the Amsterdam Study of the Elderly (AMSTEL)

BACKGROUND

This study examines whether risk factors related to incidence of depression are also related to prognosis, and whether a vulnerability-stress model can be established for prognosis.

METHODS

A prospective model for prognosis of depression (chronic or remitted course) in later life was studied in 236 depressed community-living elderly. Subjects were interviewed at baseline, and at follow-up 3 years later. Bivariate and multivariate relationships between risk factors and chronic depression (GMS-AGECAT) were assessed. Effect modification was studied between stressors and two types of vulnerability: vulnerability through a personal history of depression, and gender.

RESULTS

A personal history of depression, baseline functional limitations and incident anxiety syndrome predicted chronic depression, whereas life-events occurring between assessments, and changes in physical, functional or cognitive status did not. In subjects without a previous history, functional disabilities, male gender and receiving instrumental support correlated with a poor prognosis. The prognosis for subjects with a personal history of depression was not affected by other factors. In women, the development of chronicity was more strongly associated with a personal history than in men, whereas in men recent psychosocial and health-related characteristics were more important than in women.

LIMITATIONS

Because the study consisted of two measurements with a 3-year interval, depressive episodes with a short duration may be under-represented.

CONCLUSIONS

In the elderly, the impact of risk factors on the course of depression is modified by longstanding vulnerability characteristics, such as a personal history of depression and gender. More recent life stresses are related to prognosis in subjects without a personal history, and in men.

Mode density inside an omnidirectional mirror is heavily directional but not small

We show that ominidirectional reflection is not a sufficient signature of a photonic bandgap. Although dramatic angular redistribution takes place, the mode density of the electromagnetic field is hardly altered within the ominidirectional reflection range but rather has characteristics typical of a waveguide. The strikingly large polarization anisotropy is due to the huge dielectric contrast but not to a photonic bandgap.

Nonlinear EEG analysis in early Alzheimer's disease

Nonlinear EEG analysis attempts to characterize the dynamics of neural networks in the brain. Abnormalities in nonlinear EEG measures have been found repeatedly in Alzheimer's disease (AD). The present study was undertaken to investigate whether these abnormalities could already be found in the early stage of AD. In a representative sample of 49 community-dwelling elderly, Alzheimer's disease was diagnosed in 7 subjects. Correlation dimension (D2) and nonlinear prediction were measured at 16 electrodes and in two different activational states. Also, 10 surrogate data sets were generated for each EEG epoch in order to investigate the presence of nonlinear dynamics. Differences between nonlinear statistics derived from original and from surrogate data sets were expressed as Z-scores. We found lower D2 and higher predictability in the demented subjects compared to the normal subjects. The results obtained with the Z-scores pointed to changed nonlinear dynamics in frontal and temporal areas in demented subjects. However, the major differences between demented and healthy subjects are not due to nonlinearity. From this it appears that linear dynamics change first in the course of AD, followed by changes in nonlinear dynamics.

Depressogenic medication as an aetiological factor in major depression: an analysis in a clinical population of depressed elderly people

OBJECTIVE

To study the role of depressogenic medication in the aetiology of major depression in the elderly.

BACKGROUND

Depression can be caused, provoked or sustained by drugs prescribed for other reasons. The evidence for this statement is based on case-reports, not on investigations in relevant populations.

METHOD

In the geriatric wards of three Dutch psychiatric hospitals, 195 patients with a DSM-III-R diagnosis of major depression (MDD) were studied. In the first week after admission the following data were recorded: age, gender, personal psychiatric history, family psychiatric history, Montgomery-Asberg Depression Rating Scale, Mini-Mental State Examination, history of stroke, use of medication and number of different medications used. Subjects using depressogenic medication were contrasted with subjects not using depressogenic medication on all variables.

RESULTS

There was a significant negative relationship, adjusted for the other variables, between the use of depressogenic medication and a previous admission for depression. No other significant relationships between the use of depressogenic medication and aetiological variables were found. Patients with a first-time admission for MDD use depressogenic medication 2.44 times more often than patients with previous admissions for depression.

CONCLUSION

The use of depressogenic medication is an independent and clinically relevant aetiological factor in MDD.

Depression in Europe. Geographical distribution among older people

BACKGROUND

This is the first report of results from the EURODEP Programme.

AIMS

To assess the prevalence of depression judged suitable for intervention in randomised samples of those aged > or = 65 in nine European centres.

METHOD

The GMS-AGECAT package.

RESULTS

Differences in prevalence are apparent, 8.8% (Iceland) to 236% (Munich). When sub-cases and cases are added together, five high- and four low-scoring centres emerge. Women predominated over men. Proportions of sub-cases to cases revealed striking differences but did not explain prevalence. There was no constant association between prevalence and age. A meta-analysis (n = 13,808) gave an overall prevalence of 12.3%, 14.1% for women and 8.6% for men.

CONCLUSIONS

Considerable variation occurs in the levels of depression across Europe, the cause for which is not immediately obvious. Case and sub-case levels taken together show greater variability, suggesting that it is not a matter of case/sub-case selection criteria, which were standardised by computer. Substantial levels of depression are shown but 62-82% of persons had no depressive level. Opportunities for treatment exist.

Apolipoprotein E phenotype is not related to late-life depression in a population-based sample

Apolipoprotein E (ApoE) allele frequencies were examined in a population-based sample (n = 475: age range 65-84 years: Amsterdam Study of the Elderly). The relation of ApoE epsilon 4 with dementia and with various types of late-life depression was studied. Depression was measured with the Geriatric Mental State schedule. Dementia was diagnosed by DSM-III-R criteria. It was expected that ApoE epsilon 4 allele frequencies would be elevated not only in Alzheimer's disease and dementia in general, but also in first episode, late-life depression accompanied by subtle cognitive impairment (possibly organic depression). However, the results indicated that epsilon 4 allele frequency is related to (family history of) dementia and cognitive impairment, but not to possibly organic depression. The main predictor of late-life depression is an episode of psychiatric problems before the age of 65 years.

Low education is a genuine risk factor for accelerated memory decline and dementia

A relatively high prevalence and incidence of dementia have been found in population strata with low levels of education in comparison to population strata with high levels of education. However, doubt remains whether this may be an artifact of education bias in the screening tests used. To investigate this matter, we analyzed results of two Dutch population surveys in which unbiased measures of memory decline were used. In the Longitudinal Aging Study Amsterdam (n = 1774) the percentage of words retained in a verbal learning test was found to be disproportionately low in the oldest age cohort (80-85 years) with less than 11 years of education. The Amsterdam Study of the Elderly (n = 4051) found a "dose-response" relationship between education and dementia prevalence. Cross-sectional and longitudinal results showed that, in less educated people, memory decline is faster and sets in at an earlier age. These findings indicate that the relationship between dementia and education is not just an artifact of case detection methods.

Diagnosing Alzheimer's disease in community-dwelling elderly: a comparison of EEG and MRI

In a study on the course of cognitive impairment in people over 65 years of age, 58 randomly selected community dwelling elderly underwent EEG and MRI studies. The EEG was visually and quantitatively (qEEG) assessed. Nine out of 58 subjects appeared to have Alzheimer dementia (AD) according to CAMDEX criteria. In this group medial temporal lobe atrophy on MRI, as an objective criterium for AD, showed a total accuracy of 72%, visually assessed EEG 81% and qEEG 81-84%. There was an incomplete overlap in subjects regarding MRI and EEG abnormalities, implying that both methods may be complementary.

[Item series of the cognitive screening test compared to those of the mini-mental status examination]

The items of the ¿mini-mental state examination' (MMSE) and a Dutch dementia screening instrument, the ¿cognitive screening test' (CST), as well as the ¿geriatric mental status schedule' (GMS) and the ¿Dutch adult reading test' (DART), were administered to 4051 elderly people aged 65 to 84 years. This study was part of the Amsterdam Study of the Elderly (AMSTEL-project), which is a population survey of cognitive decline and dementia. Based on the item-pool, CST and MMSE scores were calculated. Both tests were comparable as far as their validity as dementia screeners is concerned (dementia criterion was GMS Organic syndrome, cut-point 2/3). The abbreviated version of the CST (CST-14) has a somewhat lower validity. The reliabilities of the unabbreviated CST (CST-20) and the MMSE are also comparable. The influence of age, education, depression, and premorbid intelligence (DART-IQ) was most notable in the MMSE. Thus, the CST-20 item set has slightly better psychometric properties than the MMSE. A figure is presented by which CST scores can be transformed into MMSE scores.

Memory complaints and memory impairment in older individuals

OBJECTIVE

To examine whether subjective memory complaints, measured with a series of four questions, are associated with performance on cognitive tests.

DESIGN

Cross-sectional study of individuals, 65 to 85 years of age, who lived in the community of Amsterdam.

PARTICIPANTS

Individuals were selected randomly within 5-year age strata from the patient lists of 30 general practitioners. Of the 4051 participants, 2537 nondepressed and nondemented respondents were included in the analysis.

MEASURES

Four categories of subjective memory complaints were developed on the basis of answers to questions about the presence or absence of memory complaints and memory-related problems in daily functioning. Tests of cognitive function were derived from the subscales of the CAMCOG.

MAIN RESULTS

Individuals with complaints and memory-related problems performed more poorly on tests of memory and memory-related functions. This relationship was strengthened after adjusting for age, sex, and premorbid verbal intelligence, all of which were related to complaint status and to performance on cognitive tests.

CONCLUSION

Simple questions about memory function are related to memory performance in nondepressed, nondemented community-dwelling older people. Subjective memory complaints may be a promising indicator of memory impairment that signals the need for follow-up.

Subjective memory complaints may announce dementia

Whether subjective memory complaints in the absence of objective memory decline can predict future dementia has been investigated only in highly selected clinical and volunteer cohorts. Our study examines this question in a subsample of AMSTEL (Amsterdam Study of the Elderly), a longitudinal population study on cognitive decline and dementia. Subjects (aged 65 to 84 years; n = 357) without dementia or other psychiatric disorders at baseline were followed for 3 years. After this interval, 16 of 203 re-examined patients developed a dementia. Logistic regression analyses indicated that memory complaints at baseline contributed a small but significant amount of diagnostic information. However, the most powerful predictor of future dementia was deficient memory performance. We conclude that subjective memory complaints may predict dementia within 3 years, particularly when there are objective signs of memory deterioration.

Major and minor depression in later life: a study of prevalence and risk factors

In this paper, the results of a community-based study into the prevalence and risk factors associated with depression in the older (55-85 years) population of The Netherlands are presented. The prevalence of major depression was 2.02%, that of minor depression 12.9%, while 14.9% had clinically relevant levels of depressive symptoms. Associations with a comprehensive set of risk factors were not affected dramatically by age or sex. However, comparing major to minor depression, risks were substantially differently distributed. It appears that major depression is more often an exacerbation of a chronic mood disturbance, with roots in long-standing vulnerability factors; while minor depression is more often a reaction to the stresses commonly experienced in later life.

Relation between education and dementia: the role of test bias revisited

Several authors have suggested that dementia screening tests may be biased against low levels of education, whereas others find that a low level of education is a genuine risk factor for dementia. The present paper attempts to reconcile these conflicting views by examining item bias and test bias indices of the mini mental state examination (MMSE). Psychometric calculations and receiver operating characteristics (ROC) analyses of sensitivity and specificity as performed by earlier studies were replicated and extended from the database of the Amsterdam Study of the Elderly. This is a population survey on cognitive decline and dementia (age range 65-84). Subjects with a low level of education (primary school) were compared with better educated subjects (at least some secondary education). Cases were matched by age and sex. The results indicate that the MMSE is not educationally biased as far as item characteristics, reliability, and construct validity are concerned. Yet its predictive validity as a screening test for dementia is educationally biased. This bias will effectively be eliminated with a two point higher cut off score for the subjects whose education extends beyond primary school. Even after such score correction, a low level of education probably remains a genuine risk factor for dementia.

Late-life depressive disorder in the community, early onset and the decrease of vulnerability with increasing age

This study examined reports of a history of psychiatric illness related to age and depression in 4051 community residents aged 65-84. Depression was twice as common among subjects with a history of psychiatric illness before age 65. 78% of depressed subjects reported no history. The rate of reported history was inversely proportionate to the subjects actual age. This did not appear to be due to recollection bias but it did match the proportions previously reported to result from excess mortality of individuals with a psychiatric history. A psychiatric history may be an important risk factor for late-life depression but in the aging process after age 65 it may become increasingly uncommon.

Late-life depressive disorder in the community. II. The relationship between psychiatric history, MMSE and family history

BACKGROUND

In previous studies, dementia was linked to a family history of dementia and Down's syndrome. This study tested the hypothesis that late-life depression accompanied by cognitive impairment in elderly individuals with no history of psychiatric illness is also associated with these family histories.

METHOD

We investigated an age-stratified sample of 4051 elderly people in the community aged 65-84 (AMSTEL). The relationship between family history (CAMDEX questionnaire) and depression (GMS-AGECAT diagnosis) was studied.

RESULTS

A family history of mental health problems was associated with all subtypes of depression. Family history of dementia was associated with depression in subjects with a psychiatric history, but a family history of Down's syndrome was only associated with the combination of depression and cognitive impairment in subjects with no history of psychiatric illness.

CONCLUSIONS

The heritability pattern confirms the concept of a dementia-related subtype of late-life depression.

Late-life depressive disorder in the community. I. The relationship between MMSE score and depression in subjects with and without psychiatric history

BACKGROUND

In previous studies cognitive impairment in depressed elderly in-patients tends to be associated with a late onset of depression. This study tests the hypothesis that cognitive impairment is associated with depression only in elderly individuals with no history of psychiatric illness.

METHOD

We investigated an age-stratified sample of 4051 elderly people living in the community, aged between 65 and 84 (AMSTEL). The relationship between depression (GMS-AGECAT diagnosis) and scores on the Mini Mental State Examination was studied in subjects with and without a reported psychiatric history (CAMDEX questionnaire).

RESULTS

Low MMSE scores (MMSE < or = 25) were only associated with depression in subjects with no psychiatric history (young/old: OR = 2.75, 95% CI = 1.83, 4.19; old/old: OR = 2.21, 95% CI = 1.61, 3.03).

CONCLUSIONS

We concluded that the combination of cognitive impairment and first-episode depression in elderly individuals may indicate cerebral deterioration. Depression as such may not be associated with cognitive impairment.

The prevalence of depression in elderly medical inpatients

To estimate the point-prevalence of major depression in elderly medical inpatients according to a computerized diagnostic system, a two-phase design was carried out. A consecutive series of 198 elderly medical inpatients completed two self-rating scales for depression (Beck Depression Inventory, Geriatric Depression Scale) and the Mini-Mental State Examination. According to these screening instruments, 69 'probable cases' were identified and were referred for psychiatric evaluation using the Geriatric Mental State Schedule. Only 10 patients were identified as diagnostic cases of depression according to the GMS-AGECAT package. The estimated prevalence rate for depression according to AGECAT in this population was 5.9% (95% confidence limits 2.3-9.3%). This is lower than has been found in previous studies in elderly medical inpatients. Possible reasons for this finding are discussed.

[Low serum vitamin B 12 level and vitamin B 12 deficiency in the elderly. When should supplement be provided?]

Low serum vitamin B12 levels and vitamin B12 deficiencies are frequently found in the elderly. The full syndrome of a vitamin B12 deficiency is rather simple to diagnose. The large applicability of the vitamin B12 assay also gives rise to many probably incomplete features. Low/low-normal vitamin B12 levels in screening procedures raise uncertainty whether this finding represents deficiency and should be followed by supplementation. In this paper the occurrence of low serum levels of vitamin B12 are discussed. To assess the clinical relevance of low/low-normal outcomes supplementary diagnostic procedures will be needed. Within this scope we illustrate the d.o.s.-test and the MMA-assay. Especially the latter will probably provide more answers to the treatment question. Systematic research is needed to clarify this issue. Meanwhile supplementation of all low and low-normal outcomes of the B12-assay seems the best answer.

Are age and education independent correlates of the Mini-Mental State Exam performance of community-dwelling elderly?

We examined the effects of selected health conditions and sensory functions, socioeconomic status, age, and education on cognitive functioning in 3,974 community-dwelling individuals aged 65-84 years. Logistic regression analysis was used to examine the independent and joint effects of these variables on borderline (Mini-Mental State Exam [MMSE] of 22-25) and poor (MMSE of < or = 21) functioning relative to adequate functioning (MMSE of 26-30). The effect of age and of education on MMSE performance was relatively stable, even after adjusting for age- and education-related health conditions and sensory impairments that also influenced level of cognitive functioning. These conditions included poor vision, Parkinson's disease, diabetes, depression, stroke (in 65-74-year-olds), and low socioeconomic status (in 75-84-year-olds). Education did not modify the effect of these variables on MMSE performance. Additional studies elucidating further the mechanisms that relate these sociodemographic factors to cognitive performance are warranted, as are studies of the relationship between these factors and the incidence of cognitive impairment.

[Validity of the cognitive screening tests and the mini-mental status examination in a group of elderly hospital patients]

OBJECTIVE

To study the validity of the cognitive screening test (CST) and of the mini-mental state examination (MMS).

DESIGN

Prospective administration of both CST and MMS (in balanced order) by laymen as well as by experienced users, and retrospective comparison of the scores with the clinical diagnosis and with the degree of functioning in activities of everyday life.

SETTING

Clinical and outpatient departments of Geriatrics and Neurology of the Slotervaart Hospital, Amsterdam.

PATIENTS AND METHOD

Ninety-five patients of the clinical and nine patients of the outpatient departments, with an acute somatic diagnostic problem and multiple pathology attending the above-named departments in the period from September 1989 to February 1990: 20 patients (group SOM) were found not to have a dementia syndrome; 25 patients (group DEM) had a dementia syndrome as the main diagnosis; 14 patients (group CVA) had a cerebrovascular accident as the main diagnosis without clinical signs of dementia; 45 patients were excluded from the comparison (30 because of main diagnosis from several groups and 15 because of pathology that might influence the test scores to an unpredictable degree). The data were analysed statistically by means of analyses of confidence and of variance.

RESULTS

The CST was found to be more reliable and less time-consuming than the MMS. The sensitivities of the two tests with regard to the distinction between dementia and somatic pathology were similar (80%). However, specificity of the CST was better than that of the MMS (80% and 60%, respectively).

CONCLUSION

For the screening of older patients for dementia, the CST constitutes a good alternative to the MMS.

The Hamilton Depression Rating Scale (HDRS); changes in scores as a function of training and version used

The co-existence of different versions of the Hamilton Depression Rating Scale (HDRS) may introduce a source of error in depression research. In a training procedure, based on 16 videotapes, over 900 scores were used to investigate differences between two prominent versions. The HDRS published by Bech et al. in 1986 produced significantly lower total scores than the original HDRS presented by Hamilton in 1960. Previous experience of the raters, both in psychiatry and in the use of the scale, increased the scores in a nonsignificant way. During the training raters' scores increased significantly. These effects were small, one point each in the total scores, but they were consistent throughout our material. In depression research, training procedures and the exact version of the scales used should be specified.

Reliability, validity and follow-up of the EEG in senile dementia: sequelae of sequential measurement

In a longitudinal study, slowing of the EEG in SDAT patients and elderly controls is investigated using both visual and power spectral analyses. For this a reliability study in 20 SDAT patients is performed and results for intra-rater, inter-rater and test-retest reliability (in 24 h) are used in the selection of parameters. Next, the diagnostic efficacy of the chosen parameters for SDAT is confirmed in a validity study in 43 SDAT patients, 41 elderly non-organic psychiatric patients and 51 elderly normals. In the longitudinal study 78 of these subjects could be retested after 20 months. The parameter for visual analysis appeared to be superior in actually showing a progress of slowing of the EEG in 20/21 SDAT patients over time. The parameter for power spectral analysis was superior in measuring the more subtle processes in the normal elderly. Results of these studies are used to discuss some problems in the measurement of EEG in SDAT over time.

[The Geriatric Mental Status Schedule, the GMS: psychiatric tool in psychogeriatrics]

An instrument in geriatric psychiatry, the GMS, is introduced. The use of measurement in psychiatry is briefly touched upon. The use of standardized interview like the GMS mainly serves differential diagnosis in psychiatry. The essence of this method is that questions and the appraisal of answers are submitted to rules and regulations. The application of this method in geriatric psychiatry is still in its infancy. The history of the GMS and the choice of maternal instruments following international consensus is described. In former investigations results of reliability and validity studies were satisfactory. In our own Dutch investigation reliability and validity in the (differential) diagnosis of senile dementia were consistent with those of previous studies. Some claims and restrictions in the application of the instrument are discussed.

Anterior temporal focal abnormalities in EEG in normal aged subjects; correlations with psychopathological and CT brain scan findings

Normal aged subjects (65-83 years) were examined by EEG and CT brain scan; also a Geriatric Mental Scale (GMS) and Neuropsychologic Assessment Battery were administered. Based on the EEG findings 2 subgroups could be distinguished: one with focal abnormalities in the left fronto-temporal region and one without these focal abnormalities. The focal delta subgroup proved to perform poorly on the Fluency Test, a simple quick bedside, but very sensitive, test for word association productivity. Also this subgroup showed more ventricular dilatation than the non-focal group. Therefore slight left-sided antero-temporal abnormalities in normal aged subjects are not irrelevant but an early (subclinical) sign of temporal lobe pathology as expressed in deterioration of language function.

Visual evoked potentials (VEPs) in senile dementia (Alzheimer type) and in non-organic behavioural disorders in the elderly; comparison with EEG parameters

Forty-two patients with senile dementia of the Alzheimer type were compared with normal subjects (51) and with elderly patients with nonorganic psychiatric disorders (40). All were examined by EEG (routine visual inspection and power spectrum density analysis) and VEP (pattern reversal) testing. In dementia the late components (N130, P165, N220) of the VEP are delayed, but the EEG was abnormal more often than the VEP.

Somatosensory evoked potentials in healthy volunteers and in patients with dementia

In 56 healthy volunteers short, middle and long latency somatosensory evoked potentials were recorded bilaterally. The median nerve was electrically stimulated at the wrist. The impact of arm length and age on the peak latencies of the identified SEP components was investigated. Arm length relates to shoulder and neck SEP and to the N20, the primary cortical response. Age relates to all components of the SEP. A pilot study was performed in a small number of patients with senile dementia. A significant delay of the middle and long latency potentials compared to healthy volunteers was shown.

[Multidisciplinary diagnosis of dementia and non-dementia behavior disorders in the aged. Preliminary study for research on its course and prognosis]

The need to differentiate between dementia and the so-called functional psychiatric diseases of old age is of therapeutic as well as social importance. The main symptoms of dementia--lack of memory, disorientation and cognitive disturbances--are much less clearly defined than would be desirable, despite the neuropathological changes regarded as underlying senile dementia. The disease does not always have a progressive course. Confusion is also possible with other forms of dementia, while the symptoms of dementia can also be found in so-called functional psychiatric diseases. On the basis of the literature and/of our own research, it appears that a sharper definition of senile dementia is possible. Besides clinical criteria one can make use of--partly recently introduced--diagnostic techniques, specifically a structured psychiatric interview for old people, a neuropsychological testbattery, EEG, visual evoked response techniques and CT-brain scanning. The value of these diagnostic techniques for the diagnosis and the assessment of the prognosis of senile dementia can only be determined in a follow-up study. The set-up of such a follow-up study is described.