ABSTRACT
The translation of epidemiological findings into effective preventive strategies is rarely simple. In the case of affective disorder the task is doubly complicated. On the one hand, psychiatric unlike physical illness involves the individual's conscious interpretation of environmental factors. On the other hand, the multifactorial aetiology of depression, which has come to be generally acknowledged with the final common pathway model (Akiskal and McKinney 1973), introduces a variety of items which require intricate balancing in their combination. The aetiological model of depression which I shall discuss here - the vulnerability model outlined by George Brown and colleagues - focuses upon the intervening psychological process by which the grosser sociodemographic variables examined in epidemiological research become linked with depressive disorder. Moreover, by distinguishing provoking factors from vulnerability and symptom-formation factors, it allots weightings to the many variables proposed by multifactorial models. Aetiological models distinguishing provoking from vulnerability factors may perhaps be more familiar if described in terms of stress-diathesis or hazards versus resources (see Leighton in this volume). I shall argue that this distinction can deepen our understanding of the psychological process of depressive onset, thus throwing light on the topic of prevention of depression. The research I shall review will also have a more general bearing on the interpretation of epidemiological findings in prospective enquiries. Although an attempt will be made to set the theoretical model in the context of other research findings, limitations on space unfortunately may lend a certain parochialism to the discussion.
