Community-based case-control study of depression in older people. Cases and sub-cases from the MRC-ALPHA Study

Abstract

Background: Risk factors of depression in later life, particularly for sub-cases and for psychotic and neurotic types of depression, are unclear.

Aims: To identify such risk factors.

Method: Over 5200 older people (> or = 65 years), randomly selected from Liverpool, were interviewed using the Geriatric Mental State (GMS) and the Minimum Data Set (MDS). The computer-assisted diagnosis AGECAT identified 483 cases and 575 sub-cases of depression and 2451 with no mental problems. Logistic regression was employed to examine factors relevant to caseness.

Results: In multiple logistical regression, odds ratios (ORs) were significantly high for being female (2.04, 95% CI 1.56-2.69), widowed (2.00, 1.18-3.39), having alcohol problems (4.37, 1.40-2.94), physical disablement (2.03, 1.40-2.94), physical illness (1.98, 1.25-3.15), taking medications to calm down (10.04, 6.41-15.71), and dissatisfaction with life (moderate 4.54, 3.50-5.90; more severe 29.00, 16.00-52.59). Good social networks reduced the ORs. If sub-cases were included as controls, the statistical significance was reduced.

Conclusions: Age was not associated with depression in later life whereas gender, physical disablement and dissatisfaction with life were. The sub-cases shared many risk factors with cases, suggesting that prevention may need to be attempted at an early stage.