Introduction

After a one-year follow-up period Murphy was able to show that only one third of elderly depressed patients had a satisfactory outcome (Murphy, 1983). Baldwin & Jolley (1986) found that 60% of subjects in their patient series either remained well or had further episodes followed by full recovery, when observed for a variable time of up to two years. In both studies, concomitant physical illness was associated with poor outcome. Copeland et al. (in press) in their community study of subjects aged 65 and over reported that more than 30% of those diagnosed as depressed at initial interview were depressed three years later. These studies demonstrate that depression in the elderly can present considerable therapeutic problems and that only a minority of patients seem to make a full recovery without suffering relapse or chronicity. Moreover, the onset of depression in the elderly has been shown to be associated with severe life events, major social difficulties and poor physical health, while those elderly people without a confiding relationship appear to have increased vulnerability to depression (Murphy, 1982). Such studies suggest that the elderly individual's perception of their environment, physical illness and social relationships clearly influence both the genesis and prognosis of depression.

Most clinical or psychological assessments have been limited to a single interview or to periodic, daily observer or self-report ratings. Recent research has employed a repeat measure, longitudinal design which emphasises the relationships between the individual's external environment and his or her cognitions and mood (Lader, Lang & Wilson, 1987).