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

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 (greater than or equal to 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. Declaration of interest Funding from the Medical Research Council.