Depressive illness: the role of aggression further considered.

Measures of depression and undischarged drive were obtained for 292 psychiatric in-patients. In 200 of these cases inhibition of aggression was also assessed. All patients were classified as being endogenously depressed, reactively depressed, or as suffering from non-depressive primary disorders. The latter group was subdivided into secondarily depressed and non-depressed groups. The 3 depressed groups were then compared with the non-depressed subjects in respect of drive level and inhibition of aggressionmall 3 depressed groups showed significantly higher driver level than did the non-depressed subjects. The endogenous depressives also inhibited significantly more of their aggression than did the non-depressed subjects. The results are consistent with a drive inhibition theory of depression. However, while endogenous depression seems to be associated more specifically with the inhibition of aggression, reactive depression may be associated rather with the inhibition of drive generally.