The WHO Collaborative Study on Psychological Problems in General Health Care examined the frequency, form, course and outcome of psychological problems in general health care settings. A total of 25,916 general health care attenders at 15 sites in 14 countries were screened using the 12-item General Health Questionnaire (GHQ-12). Of those screened, 5,438 were assessed in detail using a Primary Health Care version of the Composite International Diagnostic Interview (CIDI-PHC) in conjunction with the Brief Disability Questionnaire, the Social Disability Schedules, a self rated overall health status form and the 28-item General Health Questionnaire. The analysis has shown that sleep problems were common at all sites with: 26.8% of all patients having some form of sleep problem and 15% of the patients examined had trouble falling or staying asleep. Of those with sleep problems, 51.5% had a well-defined International Classification of Diseases 10th Revision (ICD-10) mental disorder (such as depression, anxiety, somatoform disorders or alcohol problems) and 48.5% of those with sleep problems for at least two weeks or more did not fulfil the criteria for any well defined ICD-10 diagnosis. Persons with sleep problems reported a degree of disability in the performance of their daily activities and social roles even when they had no symptoms of psychological disorders. When such symptoms were present the disability was significantly increased.

The present study, conducted in collaboration between the Departments of Psychiatry in Swiss Universities and the World Health Organization, had two main goals: to develop assessment methods which could subsequently be used in the Swiss centres in a standard manner; and to make arrangements for continuing collaboration between the centres in Switzerland and the acquisition of new knowledge about the distinctions between depression and cognitive impairment. For this aim, three different groups of elderly patients of either sex were selected during the period of November 1989 to July 1991 for inclusion in the study. The first two groups included the first ten patients of either sex over 60 years of age consecutively contacting the participating institutions and showing depression with or without clinically significant symptoms of cognitive impairment; the control group included patients showing no depression or clinically significant symptoms of cognitive impairment. A total of 125 patients were included in the initial evaluation, 69 of which were reassessed at a seven-month follow up (on average). Each patient was administered a number of clinician-rated or self-report instruments for the assessment of depression, cognitive impairment, disabilities, physical status and onset of disorders. The study has shown that a variety of instruments can be used for the reliable assessment of depression or cognitive impairment in the elderly; but the instruments for the assessment of depression differentiate only poorly between patients with or without cognitive impairment. Because of the importance of identifying both depressed and cognitively impaired patients among the elderly, different assessment instruments targeted at the different symptom clusters need to be administered simultaneously.

The point prevalence of depressive disorders was estimated in a sample of persons aged 70 years and over, which included both those living in the community and those in institutional settings. Lay interviewers administered the Canberra Interview for the Elderly to the subjects and their informants. The point prevalence of depressive episodes as defined by the Draft ICD-10 diagnostic criteria was 3·3%. The rate for DSM-III-R major depressive disorder was 1·0%. The latter prevalence rate is similar to those reported elsewhere for the elderly. Evidence is accumulating that older persons may indeed have low rates for depressive disorders at the formal case level. Possible reasons for this finding are offered.

A scale for depressive symptoms, based exclusively on those specified in Draft ICD-10 and DSM-III-R, showed that the elderly do experience many depressive symptoms. Contrary to expectation, these did not increase with age. The number of depressive symptoms was correlated with neuroticism, poor physical health, disability and a history of previous depression. Attention now needs to be directed to the clinical significance of depressive symptoms below the case level in elderly persons.

Family history of Alzheimer's disease (AD) was investigated using a telephone re-interview of 99 cases and 116 controls selected from a case–control study of 170 matched pairs. It was found that the family history method used in the initial interview was satisfactory in identifying first-degree relatives and assessing their ages of birth and death, but the number of first-degree relatives suffering from AD was probably under-estimated. Family history of AD was confirmed as a risk factor for AD. Higher estimates of cumulative incidence were obtained among case relatives than among control relatives. No evidence was found to support the hypothesis that a familial form of AD is more common in those with earlier onset AD (before age 75) in those who display early, prominent features of aphasia or apraxia, or that an AD gene may be sex-linked. The curves for cumulative incidence showed no tendency to reach an asymptote, as is implied by the theory that some forms of AD are due to the action of an autosomal dominant gene. Estimates of lifetime risk by age 90 were within the range found by other investigators. Much larger samples of the very old are needed to obtain estimates of total lifetime risk with smaller standard errors.

The Psychogeriatric Assessment Scales (PAS) provide an assessment of the clinical changes seen in dementia and depression. Principal components analysis and latent trait analysis were used to develop a set of scales to summarize these clinical changes. There are three scales derived from an interview with the subject (Cognitive Impairment, Depression, Stroke) and three from an interview with an informant (Cognitive Decline, Behaviour Change, Stroke). Results are reported on the reliability and validity of these scales using data from clinical samples in Sydney and Geneva and a population sample from Canberra. The scales were found to have excellent validity when judged against clinical diagnoses of dementia and depression and could distinguish Alzheimer's from vascular dementia. Cut-off points were developed to indicate correspondence between scale scores and clinical diagnoses. Percentile rank norms were developed from the Canberra population sample. The PAS is easy to administer and score and can be used by lay interviewers after training. It is intended for application both in research and in services for the elderly.

In a community survey of 873 persons aged 70 years or over, focusing on dementia, cognitive decline, depression, and current life circumstances, we included an enquiry into the emotional impact of the interview. A large majority reported at the end of the interview that it had no adverse effect on their emotional state. About 4% reported that it made them distressed, 1% that it depressed them, and 2% that it had intruded on their privacy. By contrast, 52% said it had made them feel good about themselves. Distress seemed to be largely related to performing poorly on cognitive tests. There is no information on the duration of these effects in the period following the interview. It is recommended that respondents in community surveys, including the elderly, be informed that they can decline to answer any question, and that interviewers be trained in how to respond to the few who will be distressed by the experience.

An 18-item inventory designed by Goldberg et al. (1987) to detect symptoms of anxiety and depression was administered to an elderly general population sample. Latent trait analysis was used to assess the dimensionality of the inventory and the location and discriminatory ability of the symptoms. The items showed different patterns of discrimination in this group compared to the sample of general practice attenders on which the inventory was developed. Overall, the items did define two correlated dimensions of anxiety and depression. In addition, a third dimension of sleep disturbance was detected. Both individual scales and the total symptom scores were sensitive and relatively specific detectors of depressive disorders assessed according to ICD-10 and DSM-III-R criteria. The retention of sleep items on their original scales did not affect the sensitivity of the scales to detect depressive disorders. A two-step administration procedure suggested for use in the administration of the scales was investigated but found to be sensitive to differences between the current sample and the sample on which the inventory was developed. This symptom inventory can be recommended for use in epidemiological investigations as a brief, valid and acceptable method of detecting elevated levels of anxiety and depression in elderly persons.

Season of birth was compared in 170 clinically diagnosed cases of Alzheimer's disease (AD) in Australia and 170 matched controls. A further comparison was made with a large population sample of the elderly. No evidence for seasonality of birth was found. This finding held not only for the total series of 170 cases, but also for the 143 born in the Southern Hemisphere, for sporadic cases, and for those with earlier onset. These negative findings in Australia contrast with the positive finding in London by Philpot et al. (1989).

A community survey of 1045 persons aged 70 years and over was conducted to identify cases of dementia in the cities of Canberra and Queanbeyan. Cases were identified using the Canberra Interview for the Elderly, administered by lay interviewers. When diagnostic criteria were rigidly applied, the point prevalence of dementia in the combined sample of community and institutional residents was considerably lower by ICD-10 than by DSM-III-R. Both criteria showed a similar rise in prevalence with age, and no gender difference. Agreement between the two systems had a kappa of only 0·48. ‘Probable’ cases by either criteria were identified solely from respondent-provided information in order to include persons for whom no informant was available. The point prevalence of such ‘probable’ cases was more similar for the two systems, and the kappa coefficient of agreement rose to 0·80. Analysis of the various components required for a diagnosis of dementia showed that the prevalence of all increased with age. Components involving cognitive assessment were correlated with education, but other components were not. The results of the study point to important differences between ICD-10 and DSM-III-R diagnoses of dementia.

Criteria for the diagnosis of ICD-10 Mild Cognitive Disorder (MCD) were applied to a sample of 897 community dwelling elderly participants. Criterion A (the presence of a physical disorder) was met by 44%, Criterion B (report of a cognitive disorder) by 17%, Criterion C (an abnormality in quantified cognitive assessments) by 60%, and Criterion D (exclusion on basis of dementia and other conditions) by 74%. A total of 36 cases (4%) met all four criteria. Correlations between Criteria A and B, and B and C were weak (r = 0·18), and the correlation between Criteria A and C was almost zero (r = 0·02). This suggests that no syndrome exists. Membership of MCD was predicted by a report that memory or intelligence interfered with daily life but not by performance on cognitive tests or by a report of physical illness. Cases of MCD had higher anxiety, depression and neuroticism scores than normal elderly, but did not differ substantially on tests of cognitive functioning. These findings call into question the validity of the ICD-10 diagnosis of MCD.

In a community survey, subjects and their informants were asked the same questions about memory and intellectual decline in the subjects. Subjects and informants both commonly reported cognitive decline, although in most cases the decline was not seen as interfering with daily life. However, when responses from subjects and informants were cross-tabulated, agreement was found to be poor. For subjects, reports of cognitive decline were correlated with anxiety and depression symptoms and with trait neuroticism. Subjects' reports were uncorrelated with age and only weakly correlated with cognitive test performance, indicating little validity. By contrast, informants' reports were correlated with the subjects' cognitive test performance and age, but also with the informants' own anxiety and depression symptoms. Although informants' reports have validity, they may also be contaminated by the informants' affective state.

In a context of a WHO collaborative study, 12 research centres in 10 countries monitored geographically defined populations over 2 years to identify individuals making a first-in-lifetime contact with any type of ‘helping agency’ because of symptoms of psychotic illness. A total of 1379 persons who met specified inclusion criteria for schizophrenia and other related non-affective disorders were examined extensively, using standardized instruments, on entry into the study and on two consecutive follow-ups at annual intervals. Patients in different cultures, meeting the ICD and CATEGO criteria for schizophrenia, were remarkably similar in their symptom profiles and 49% of them presented the central schizophrenic conditions as defined by CATEGO class S+. However, the 2-year pattern of course was considerably more favourable in patients in developing countries compared with patients in developed countries, and the difference could not be fully explained by the higher frequency of acute onsets among the former. Age- and sex-specific incidence rates and estimates of disease expectancy were determined for a ‘broad’ diagnostic group of schizophrenic illness and for CATEGO S+ cases. While the former showed significant differences among the centres, the differences in the rates for S+ cases were non-significant or marginal. The results provide strong support for the notion that schizophrenic illnesses occur with comparable frequency in different populations and support earlier findings that the prognosis is better in less industrialized societies.

Data from a case-control study of Alzheimer's disease (AD) were analysed in relation to age of onset and familial/sporadic status. The analyses were restricted to environmental exposures which might injure the brain. Later-onset AD was found to be positively associated with starvation/malnutrition and with nose-picking and negatively with analgesics, while earlier-onset was associated with physical underactivity and nervous breakdown more than 10 years before. Sporadic AD was associated with starvation/malnutrition and with head injury. These analyses merit replication in other large case-control studies of AD.

Background. Many people who are depressed do not receive any professional help and their beliefs about the helpfulness of treatment do not always correspond with those of health professionals. To facilitate choices about treatment, the present study examined the effects of providing depressed people in the community with evidence on whether various treatment options work.

Method. A randomized controlled trial was carried out with 1094 persons selected at random from the community who screened positive for depressive symptoms and agreed to participate. Participants were mailed either an evidence-based consumer guide to treatments for depression or, as a control, a general brochure on depression. Outcomes were the rated usefulness of the information provided, changes in attitudes to depression treatments, actions taken to reduce depression, and changes in depressive symptoms, anxiety symptoms and disability.

Results. Participants rated the evidence-based consumer guide as more useful than the control brochure. Attitudes to some treatments changed. Improvements in symptoms and disability did not differ significantly between interventions.

Conclusion. Providing people who are depressed with evidence on which treatments work produces some changes in attitudes and behaviour. However, this intervention may need to be enhanced if it is to produce symptom change.

Background. There is considerable dispute about the validity of memory complaints. While some studies find that complaints are an early indicator of dementia or cognitive decline, there are also many studies showing that complaints are more closely associated with negative affect (depression, anxiety and neuroticism). The present paper used three-wave longitudinal data to test three hypotheses: (1) that memory complaints reflect an evaluation of present and past memory performance; (2) that memory complaints predict future memory performance; and (3) that memory complaints predict current and future negative affect.

Methods. A longitudinal study was carried out with a community sample of people aged 70 and over. Participants were assessed for memory complaints, memory performance and negative affect at three waves separated by 3·6 years and 4·0 years. There were 331 persons with data on all relevant variables. The data were analysed using structural equation modelling.

Results. Significant paths in the structural model were found from memory performance to future memory complaints, as well as from memory complaints to future memory performance, supporting hypotheses 1 and 2. Memory complaints were associated with current negative affect, but did not predict future negative affect.

Conclusions. Memory complaints do reflect perceptions of past memory performance and are also an early manifestation of memory impairment. However, current negative affect (anxiety and depression symptoms) shows the greatest association with memory complaints.

Background. Higher education has been posited to protect against cognitive decline, either because the rate of decline is slower in the more highly educated or the start of decline is delayed. Latent growth models provide improved methodology to examine this issue.

Methods. The sample consisted of 887 participants aged 70–93 years in 1991 and followed up in 1994 and 1998. Latent growth models and standard regression techniques were used to examine the rate of cognitive decline in four cognitive measures while controlling for health status and sex. A delayed start model was examined by incorporating interaction effects in a regression model.

Results. Neither the latent growth models nor the regression techniques revealed a slower rate of decline for the more highly educated. The proportion of the highly educated showing no change was no larger than the proportion of the less well educated. There were no significant age by education interaction effects, no chronologically later accelerations in the rate of change as a function of education, and no differences in rate of decline between the first measurement interval and the second.

Conclusions. Education may not protect against cognitive decline although it is associated with long-term individual differences in level of functioning. The discrepancy between our study and others may be attributable to attrition effects, follow-up length, sample age, scaling artefacts and negative publication bias. Most importantly, practice effects may favour the better educated and hence account for the supposed protective effect in many longitudinal studies of cognitive change.

Background. Informant questionnaires on cognitive decline are increasingly used as screening tests for dementia. Informants can provide a longitudinal perspective that is not possible with cognitive screening tests administered at one point in time. However, there are limited data on the validity of such questionnaires when judged against longitudinal change on cognitive tests.

Methods. A community sample of elderly people aged [ges ] 70 was assessed on cognitive tests at baseline and after a follow-up of 7–8 years. The participants were given the Mini-Mental State Examination and tests of episodic memory and mental speed. At follow-up, the short-form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) was completed by informants for 287 of the participants.

Results. Elderly people who were rated by informants as having moderate or severe decline had declined significantly on cognitive tests. The IQCODE correlated as highly with cognitive test change scores as these change scores correlated with each other.

Conclusions. The IQCODE is a valid way of assessing cognitive decline when assessment can be carried out only at one point in time.