Depression, delusions, and suicide.

A retrospective analysis of all the suicides at the New York State Psychiatric Institute over a 25-year period was carried out. The authors retrospectively assigned diagnoses according to Research Diagnostic Criteria and DSM-III and found that among the patients who committed suicide there were 14 with unipolar endogenous depression. Of those 14 patients, 10 were considered delusional or probably delusional. In comparison, a control group of similarly diagnosed depressed patients taken from the same institution over the same time period included far fewer delusional depressions. Thus, there was a significant association between delusions and suicide: A delusionally depressed patient was five times more likely to commit suicide than a nondelusional one.