Psychotic Depression: Diagnosis, Differential Diagnosis, and Treatment.

Psychotic depression was initially considered to be at one end of a continuum of severity of major depression. Subsequent experience demonstrated that psychosis is an independent trait that may accompany mood disorders of varying severity. While much has been learned about the impact of severe mood congruent delusions and hallucinations on the course and treatment response of depression, less is known about fleeting or mild psychosis, mood incongruent features, or psychotic symptoms that reflect traumatic experiences. Acute treatment of psychotic unipolar depression generally involves the combination of an antidepressant and an antipsychotic drug or electroconvulsive therapy. There is inadequate information about maintenance treatment of unipolar psychotic depression and acute and chronic treatment of psychotic bipolar disorder. Decision-making therefore still must rely in part on clinical experience.