Genetic vulnerability for depression and life events

In the last decades there has been an increased interest in studies of life events and depression. Although evidence has accumulated suggesting that life events might be relevant for the occurrence and development of depression, their pathogenic role is still poorly understood. In the present study, we have investigated whether a possible interaction exists between external events and biological vulnerability for depression. On the basis of an intensive family study, 128 depressed patients, consecutively admitted to the department of psychiatry of Umeå University Hospital have been divided into 2 groups, those suffering from 'depression pure disease' (i.e. those with a family loading for affective disorders, n = 48) and, those suffering from 'depression sporadic disease' (i.e. those without any heredity for affective disorders, n = 80) according to Winokur's classification. The occurrence of life events has been assessed in each patient by means of a semistructured interview. The mean number of events experienced by the patients in the two groups proved to be similar during the different time periods taken into account, and the mean number of events per patient was similar to that found by other authors who studied life events and depression. None of the categorizations used to group the life events discriminated between the groups. It is concluded from this study that genetic vulnerability for depression does not enhance an individual's vulnerability for stressful events.