Physical Ill-Health, Age and Depression

Abstract

The prevalence of disease can only be assessed by community studies. Such studies of depression are fraught with the difficulties of defining not only the limits of illness but also the diagnostic criteria to be used. As a result it is difficult to compare the results of the various studies which have been done on samples of elderly subjects. Most workers have attempted to distinguish two types of depression. Although they are variously named, the divisions broadly adopted can be equated with severe and minor illness. From the first major study to examine a random sample of elderly community subjects by Kay et al. (1964), to our own investigations (Copeland et al. 1987 a), the reported prevalence of severe or major depression has varied only between 1.0%–4.0%, which is perhaps a surprising degree of agreement given the diverse criteria used (Weissman and Myers 1980; Persson 1980; Blazer and Williams 1980; Blazer 1982; Cooper and Schwartz 1982; Gurland et al. 1983; Kay et al. 1985; Copeland et al. 1987 a, b). The prevalance of minor depression has varied rather more widely between studies. This is not surprising as defining the limits of illness and normal behaviour are additional problems which bedevil the study of neurotic conditions. It also seems possible that the levels of minor depression may truly vary between populations. In our study we used standardized semistructured methods for assessing mental state, the Geriatric Mental State (GMS) AGECAT Package, and a computer diagnostic system (Copeland et al. 1986).