The importance of mood-incongruent psychotic symptoms in melancholia.

We examined the clinical, genetic and prognostic significance of mood-incongruent psychotic symptoms in a sample of melancholic patients with and without such features, and a control group of schizophrenic patients. We found no differences between the two depressive groups for any of the important variables studied, but marked differences for both groups in comparison with the schizophrenic sample. Mood-incongruent psychotic symptoms do not appear to identify a unique sub-population of melancholia.