The significance of depression in the prediction of relapse in chronic schizophrenia.

The prospective monitoring of two separate groups of chronically schizophrenic patients on regular depot maintenance therapy suggests that depression developing after an interval of 1 year from recovery from an acute relapse indicates a significant increase in the risk of a further relapse within 2 years, compared with depression within the first year, or no depression. Patients with such depression were more prone to relapses than other patients, despite regular medication within normal dose ranges. The results suggest that the aetiology of depression occurring in patients after 1 year in a stable mental state is different from that of depression within the first year, and in many patients, the former represents underlying schizophrenic activity prior to an early relapse.