Association of life events and psychosocial factors with early but not late onset depression in the elderly: implications for possible differences in aetiology.

BACKGROUND: Depression occurring for the first time in later life (after age 60, late onset depression (LOD)) may have a different, more organic, aetiology from early onset depression (EOD). We investigated the possible role of life events, the presence of a confidante and personality factors in the aetiology of depression in the elderly, testing the hypothesis that these factors would be associated with EOD but not LOD.

METHODS: Subjects consisted of 66 elderly patients (aged over 60) with DSM-IV Major depression (30 EOD, 33 LOD; groups matched for age) and 38 age and sex matched controls. Life events in the 12 months prior to onset of depression (or prior to interview for controls) were recorded using a previously validated 12-item scale. Personality was assessed using the Eysenck Personality Questionnaire (EPQ).

RESULTS: Subjects with EOD reported having a close confidente significantly less frequently (52%) than controls (82%, p < 0.05) or LOD (80%, p < 0.05). Bereavement life events occurred significantly more frequently in EOD (52%) than LOD (16%, p < 0.01) and were also more frequent in controls (42%) than LOD (p < 0.05). Higher EPQ 'extraversion' and 'neuroticism' were found in both EOD and LOD compared to controls, with no differences between EOD and LOD.

CONCLUSIONS: LOD was associated with fewer bereavement life events and more frequent presence of a confidente than EOD. This supports a greater role for psychosocial factors in the aetiology of EOD and different, probably neurobiological, factors in LOD. Personality attributes may have a greater relevance for both EOD and LOD than previously recognized.