Treatment, prediction of relapse and prognosis of chronic primary major depression.
Our study of chronic and non-chronic depressive patients suggests that the following individual factors may predispose a patient to develop chronicity: unipolar depression, neurotic premorbid personality, high familial loading for affective disorder and multiple life events before and after the onset of the illness episode. It is interesting to note that bipolar disorders appear to be under-represented. This may be due to symptomatic chronicity in bipolar illness being more often represented by rapid cycling disorder. Evidence from a group of prospectively ascertained depressives with a median duration of illness of one year showed that apparently 75% of the variance in length of illness episode can be explained. Thus time taken to introduce active treatments, premorbid neuroticism, the occurrence of life events before and after the onset of illness, age at onset of first illness episode and family history of affective disorders were confirmed as important predictor variables. The fact that 85% of patients who develop chronic primary major depressive disorders have previously had an episode of affective illness tends to militate against the stereotype of these patients having a personality disorder. In future, it is important that biological research (for example, neuroendocrine studies) is directed towards chronically depressed patients. In the past, these patients have tended to be excluded from such studies as they represent an atypical population. It is therefore quite clear that future research should be directed towards not only pharmacological but also psychological and social mechanisms which lead to the perpetuation of depressive illness.