• A consecutive series of inpatients with primary unipolar depression was categorized by the presence or absence of delusions as noted in the charts. The systematically obtained follow-up material contained in these charts showed that delusional patients had a relatively poor short-term outcome regardless of whether they received somatic treatment.Recovery rate increased with longer follow-up periods in both groups. In accord with this, a 40-year follow-up revealed no differences between delusional and nondelusional groups in terms of marital, residential, or occupational status, psychiatric symptoms, a final diagnosis of bipolar disorder, or death by suicide.
Coryell W, Tsuang MT. Primary Unipolar Depression and the Prognostic Importance of Delusions. Arch Gen Psychiatry. 1982;39(10):1181-1184. doi:10.1001/archpsyc.1982.04290100051008