A case-control study of Alzheimer's disease in Australia.

We conducted a case-control study of clinically diagnosed Alzheimer's disease (AD) on 170 cases aged 52 to 96 years, and 170 controls matched for age, sex and, where possible, the general practice of origin. Trained lay interviewers naive to the hypotheses and to the clinical status of the elderly person carried out risk-factor interviews with informants. Significant odds ratios were found for 4 variables: a history of either dementia, probable AD, or Down's syndrome in a 1st-degree relative, and underactivity as a behavioral trait in both the recent and more distant past. Previously reported or suggested associations not confirmed by this study include head injury, starvation, thyroid disease, analgesic abuse, antacid use (aluminum exposure), alcohol abuse, smoking, and being left-handed.

Association of smoking and personality with a polymorphism of the dopamine transporter gene: results from a community survey.

In studies that used mixed volunteer samples, Lerman et al. [1999: Health Psychol 18:14-20] and Sabol et al. [1999: Health Psychol 18:7-13] reported on an association of smoking with a polymorphism of the dopamine transporter gene. We attempted to replicate this association in a nonvolunteer community sample of 861 Caucasians. No associations were found with either smoking initiation or smoking cessation. Sabol et al. [1999] also reported on an association of the dopamine transporter polymorphism with the personality trait of novelty seeking. However, we failed to find any associations with a range of personality traits, including a scale of fun seeking that correlates with novelty seeking. These negative findings suggest that either the original associations are not replicable or that any association is very small.

COMT and DRD3 polymorphisms, environmental exposures, and personality traits related to common mental disorders.

In a community sample of 2,327 Caucasians, we tested the hypotheses that polymorphisms in the COMT and DRD3 genes are associated with personality traits conferring vulnerability to anxiety, depression, or alcohol misuse, or with current symptoms of these; and that the association is stronger in persons who also have been exposed to stressor experiences. To conserve resources and to allow replication, the genetic analysis was undertaken in two stages. For the COMT polymorphism, no statistically significant associations were found in the first sample of 862 persons. The remainder of the sample was therefore not analysed for that gene. For the DRD3 polymorphism, those in the first sample with at least one of the Ser(9) alleles had significantly higher scores in neuroticism (p=0.006) and behavioral inhibition (p=0.003). There was a trend, failing to meet the 1% significance criterion, for those with this genotype also to have higher depression and anxiety. The groups did not differ in alcohol use. In persons with the Ser(9) allele who were also exposed to stressors, there was a higher level of depression at the 5% level; and the depression level was higher in homozygotes. But when the remainder of the sample (1,465) was analysed, none of the associations reached statistical significance. We conclude that neither the COMT nor DRD3 polymorphisms are associated with anxiety, depression, or alcohol abuse. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:102-107, 2000

Control-informant agreement on exposure history in case-control studies of Alzheimer's disease.

Data on control-informant agreement from four published case-control studies of Alzheimer's disease are compared, using both the kappa statistic and proportion of agreement for the presence and absence of exposures. Agreement was best for exposures involving lifestyle, medical interventions or disorders of more recent origin, and worst for exposures which involved judgements by the respondent. Agreement levels are similar across studies, and are commensurate with levels of specificity and sensitivity to be expected in this type of enquiry. We discuss the problems and implications associated with the interpretation of data from such studies of the elderly.

Association of a functional polymorphism of the monoamine oxidase A gene promoter with personality and psychiatric symptoms.

A functional polymorphism in the promoter of the monoamine oxidase gene has recently been described by Sabol et al. This polymorphism is a strong candidate for associations with personality traits and psychiatric symptoms. We report relevant data from a general population sample of 850 Caucasian Australians. We found no associations with anxiety and depression symptoms, with personality traits that predispose to anxiety (neuroticism, behavioral inhibition, negative affect) or to a personality trait related to antisocial behavior (psychoticism).

Computerised diagnosis in acute psychiatry: validity of CIDI-Auto against routine clinical diagnosis.

The validity of the self-administered CIDI-Auto for detecting ICD-10 diagnoses was assessed in a study of 126 patients admitted to an acute psychiatry unit. A comparison was made between the level of agreement of the CIDI-Auto with a psychiatrist and that between two psychiatrists. The CIDI-Auto generated an average of 2.3 diagnoses per subject, and the psychiatrists 1.3. Agreement measured by overall agreement and by Kappas between the CIDI-Auto and the psychiatrist's principal diagnosis was poor, whereas agreement between psychiatrists was good. At the level of general diagnostic class (e.g. substance use disorder, schizophrenic disorder, mood disorder), agreement between CIDI-Auto and psychiatrist on principal diagnosis was poor, Kappa = 0.23, while agreement between psychiatrists was good, Kappa = 0.69. The findings indicate that the self-administered CIDI-Auto has poor validity measured against clinical diagnosis for hospitalised patients of acute psychiatric services. Poor validity of computer-based diagnosis limits the diagnostic utility of these methods in clinical situations. It also creates uncertainty of diagnostic findings in survey use.

Risk factors for depression and anxiety in abstainers, moderate drinkers and heavy drinkers.

AIMS: To identify risk factors for depression and anxiety that are more prevalent in abstainers than in moderate drinkers and to estimate their contribution to U-shaped relationships of depression and anxiety with alcohol consumption. DESIGN: Cross-sectional general population sample. SETTING: Canberra, Australia. PARTICIPANTS: 2725 subjects completed questionnaires, including 1128 men and 1258 women aged 18-59 years. MEASUREMENTS: Consumption categories from AUDIT quantity/frequency items: (1) non-drinkers (no alcohol in the past year), (2) occasional drinkers (monthly or less), (3) lower-level drinkers (up to 14 standard drinks per week for men and seven for women), (4) higher-level drinkers (up to 28 and 14 standard drinks per week, respectively), and (5) those drinking at hazardous or harmful levels (over 28 and 14 standard drinks per week, respectively). Goldberg and DSSI/sAD depression and anxiety scales. A range of demographic, socio-economic, socio-environmental and personality factors. FINDINGS: Non-drinkers were more likely than lower-level drinkers to have low status occupations, poor education, current financial hardship, poor social support and recent stressful life events, and scored lower on extraversion, fun-seeking and drive. Many of these characteristics also applied to hazardous/harmful drinkers. In multivariate models, these risk factors accounted for a substantial part of the higher depression and anxiety scores of non-drinkers and occasional drinkers relative to lower-level drinkers. CONCLUSIONS: Abstainers have a range of characteristics known to be associated with anxiety, depression and other facets of ill health, and these factors may contribute significantly to their elevated levels of depression and anxiety.

Patterns of association between alcohol consumption and symptoms of depression and anxiety in young adults.

AIMS: Recent epidemiological findings indicate that non-drinkers as well as hazardous/harmful drinkers experience higher levels of distress than moderate drinkers. Little is known about the age at which this develops. This paper examines levels of affect, depression and anxiety over the full range of alcohol consumption in young adults. DESIGN: Cross-sectional findings from the first wave of a prospective, longitudinal study are presented. PARTICIPANTS: The general population sample comprised of 2404 young adults (aged 20-24 years). living in the Canberra region. Measures included: the Goldberg Depression and Anxiety scales, the Positive and Negative Affect Schedule, and the Alcohol Use Disorders Identification Test. FINDINGS: For men, both non/occasional and hazardous/harmful consumption were associated with lower levels of positive affect and higher levels of anxiety and depression. The higher levels of distress evident for male abstainers were related to being less extroverted and less healthy and not to past hazardous/harmful alcohol consumption, current tobacco or marijuana use. For women, only hazardous/harmful drinkers were found to have higher levels of depression and negative affect. Hazardous/harmful consumption was related to using marijuana, tobacco and recent stressful events in both men and women. CONCLUSIONS: Higher levels of distress are already evident in male non-drinkers in early adulthood. The findings counter theories that distress in non-drinkers is due to past hazardous/harmful alcohol consumption, marijuana or tobacco use, or characteristics in common with hazardous/harmful drinkers. Alcohol use disorders and mental health problems are pertinent issues for young adults. However, more understanding is needed of the experiences of non-drinkers in an alcohol consuming culture.

Health, cognitive, and psychosocial factors as predictors of mortality in an elderly community sample.

STUDY OBJECTIVE: To examine whether cognitive and psychosocial factors predict mortality once physical health is controlled. DESIGN: A prospective study of community dwelling elderly. Mortality was assessed over a period of 3-4 years after the baseline assessment of predictors. The data were analysed using the Cox proportional hazards model. SETTING: Canberra and Queanbeyan, Australia. PARTICIPANTS: A sample of 897 people aged 70 or over and living in the community, drawn from the compulsory electoral roll. RESULTS: For the sample as a whole, the significant predictors of mortality were male sex, poor physical health, poor cognitive functioning, and low neuroticism. Men had an adjusted relative risk of mortality of 2.5 compared with women. For the male sub-sample, poor self rated health and a poor performance on a speeded cognitive task were significant predictors, while for women, greater disability, low systolic blood pressure, and a low score on a dementia screening test were the strongest predictors. CONCLUSIONS: Mortality was predicted by physical ill health and poor cognitive functioning. Psychosocial factors such as socioeconomic status, psychiatric symptoms, and social support did not add to the prediction of mortality, once sex, physical health, and cognitive functioning were controlled. Mortality among men was more than twice that of women, even when adjusted for other predictors.

Predicting anxiety and depression from personality: is there a synergistic effect of neuroticism and extraversion?

In a longitudinal study of college students, B. S. Gershuny and K. J. Sher (1998) found that high neuroticism and low extraversion had a synergistic effect in predicting anxiety and depression 3 years later. This article attempted to replicate their finding using data from 2 community samples: (a) a cross-sectional survey of 2,677 persons aged 18-79 years, and (b) a longitudinal study in which 441 persons aged 70 or older were followed over 3-4 years. Both studies found that neuroticism predicted anxiety and depression, but there were no Neuroticism x Extraversion interaction effects. These results cast doubt on the generalizability of the original findings.

Age differences and interindividual variation in cognition in community-dwelling elderly.

The cognitive test performance of 897 community-dwelling elderly Ss, aged 70 years and over, was examined for age trends and interindividual variation. Data were subjected to factor analysis, and 3 factors emerged (Crystallized Intelligence, Fluid Intelligence, and Memory). Over the age span sampled, Crystallized Intelligence, Fluid Intelligence, and Memory all decreased with the decrease being greatest for Fluid Intelligence and least for Crystallized Intelligence. Interindividual variation increased for Fluid Intelligence and Memory, but not for Crystallized Intelligence. These findings give support to the view that crystallized intelligence is lower in the very old and that there is a greater degree of variability in test performance with advancing age.

An analysis of diversity in the cognitive performance of elderly community dwellers: individual differences in change scores as a function of age.

This longitudinal study investigated whether age is associated with increases in interindividual variability across 4 ability domains using a sample of 426 elderly community dwellers followed over 3.5 years. Interindividual variability in change scores increased with age for memory, spatial functioning, and speed but not for crystallized intelligence for the full sample and in a subsample that excluded dementia or probable dementia cases. Hierarchical regression analyses indicated that being female, having weaker muscle strength, and having greater symptoms of illness and greater depression were associated with overall greater variability in cognitive scores. Having a higher level of education was associated with reduced variability. These findings are consistent with the view that there is a greater range of responses at older ages, that certain domains of intelligence are less susceptible to variation than others and that variables other than age affect cognitive performance in later life.

Predictors of GP service use: a community survey of an elderly Australian sample.

As part of a study of an elderly community-dwelling Australian population, predictors of general practitioner (GP) service use were identified. The sample of 897 persons, aged 70 years or older and living in Canberra and Queanbeyan, were interviewed about their health and well-being. Data on the number of GP visits in the following 12-month period were obtained from the Health Insurance Commission. There were important gender differences in the prediction of both contact and volume of service use. Need variables (physical health in men, and disability and anxiety in women) were the most important predictors. Men who were older or who had lower occupational status used more medical services, as did women with less education or higher levels of extraversion. Men with lower social support were less likely to contact a GP, but social support was not related to volume of service use for either men or women. Since at most 21% of the variance in the volume of GP service use could be explained, despite the wide range of predictors considered and the different statistical approaches adopted, better measures of service use and predictors need to be developed.

Clinical utility and patient acceptance of the computerized Composite International Diagnostic Interview.

OBJECTIVE: The study evaluated the utility to clinicians and the acceptability to patients of the self-administered computerized version of the Composite International Diagnostic Interview (CIDI-Auto) in an acute psychiatric setting. METHODS: Patients admitted to an acute psychiatric unit completed the CIDI-Auto. Reports of CIDI-Auto diagnoses and symptoms were given to treating psychiatrists, who completed a questionnaire evaluating the accuracy and usefulness of the reports. Patients answered a questionnaire about their attitudes toward computers before completing the CIDI-Auto, and after completing it, they answered a questionnaire about their reactions to the interview. RESULTS: Psychiatrists agreed with only 50 percent of CIDI-Auto current diagnoses and indicated that only 22 percent of CIDI-Auto reports provided useful new diagnoses, although 63 percent helped to clarify diagnoses and 58 percent could save clinicians some time. They endorsed the CIDI-Auto as a possible aid to indirect or remote diagnosis where histories would be taken by nonexpert staff. Ninety-four percent of patients liked the computerized interview, and 83 percent understood the questions without difficulty. Sixty percent felt more comfortable with the computerized interview than with a doctor. Education and previous computer experience promoted positive attitudes and satisfaction with the computerized interview. CONCLUSIONS: Psychiatrists considered the current CIDI-Auto completed by patients to be of limited value in diagnosis and history taking. Despite patients' acceptance and positive reactions to the computer interview, satisfactory computerized diagnosis is yet to be attained.

A method for calculating projected increases in the number of dementia sufferers.

A new method of projecting increases in the number of dementia cases is described. This method is based on a statistical analysis of all published prevalence studies which shows that prevalence rate rises exponentially with age. The method can be easily applied to any age-specific population projections. When applied to Australia and New Zealand, the method shows that the increase in dementia will greatly exceed the total population growth rate, and even surpass the expected rise in the elderly group over the next third of a century. The method predicts that the Australian demented population will increase by 136-139% between 1984 and 2021, compared to a general population increase of only 42-54%. Over the period 1982 to 2016, the New Zealand demented population will grow by 96-100% against a rise of 18-26% in the general population. The validity of this method and its implication for future service demands are discussed.

Assessment of cognitive decline in the elderly by informant interview.

Cognitive decline in a sample of 64 elderly people was assessed by a standardised informant interview dealing with changes in memory and intelligence which had taken place in the previous 10 years. Scores from the interview were found to correlate (r = 0.74) with the Mini-Mental State Examination. Moreover, the informant interview was found to be less affected by pre-morbid ability than the MMSE. Direct assessment of decline by informants may be a solution to the problem of contamination by pre-morbid ability which affects traditional cognitive screening instruments.

Projected increases in the number of dementia cases for 29 developed countries: application of a new method for making projections.

A method is described for making projections of increases in dementia cases over a given base year. The method is based on a statistical model relating dementia prevalence to age that is derived from the results of all published prevalence studies. This method was applied to United Nations population projections for 29 developed countries to arrive at expected increases in number of dementia cases in each country for the period 1980 to 2025.

The prevalence of dementia: a quantitative integration of the literature.

Data from studies of dementia prevalence between 1945 to 1985 were analyzed statistically. Prevalence rates were found to vary as a function of methodological differences between studies. However, despite these differences, the relationship between prevalence and age was found to be consistent across studies, with rates doubling every 5.1 years. Across studies, Alzheimer's disease (AD) was found to be more common in women, with a tendency for multi-infarct dementia (MID) to be more common in men. There were also national differences in the relative prevalence of AD and MID, with MID being more common in Japanese and Russian studies, no difference in Finnish and American studies, and an excess of AD in other Western European countries.

Aspirin, anti-inflammatory drugs and risk of dementia.

OBJECTIVE: To test the hypothesis that aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) may prevent dementia or cognitive impairment. DESIGN: A two-wave longitudinal study over 3.6 years. SETTING: A community survey of elderly persons living in Canberra, Australia. PARTICIPANTS: There were 1045 elderly persons aged 70 at the start of the study; cognitive assessment was obtained at both waves on 588. MAIN OUTCOME MEASURES: Cognitive functioning was measured using the Mini-Mental State Examination, an episodic memory test, a test of mental speed and the National Adult Reading Test. Dementia was assessed using the Canberra Interview for the Elderly. RESULTS: On cross-sectional data, those who had been taking NSAIDs or aspirin performed no better on the cognitive tests after account had been taken of other confounding variables. There was no interaction with apolipoprotein E genotype. On longitudinal data, no difference was found between NSAID or aspirin users and controls, either in cognitive decline or incidence of dementia. CONCLUSIONS: The results do not support the hypothesis that aspirin or NSAIDs have a protective effect, but it remains possible that various sources of measurement error may have attenuated an effect of clinical significance from either type of drug. Conclusive evidence can be obtained only by a prospective trial.

Informant ratings of cognitive decline in old age: validation against change on cognitive tests over 7 to 8 years.

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 > or = 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.