Psychotic depression, also known as depressive psychosis, is a major depressive episode that is accompanied by psychotic symptoms. It can occur in the context of bipolar disorder or major depressive disorder. It can be difficult to distinguish from schizoaffective disorder, a diagnosis that requires the presence of psychotic symptoms for at least two weeks without any mood symptoms present. Unipolar psychotic depression requires that psychotic symptoms occur during severe depressive episodes, although residual psychotic symptoms may also be present in between episodes (e.g., during remission, mild depression, etc.). Diagnosis using the DSM-5 involves meeting the criteria for a major depressive episode, along with the criteria for "mood-congruent or mood-incongruent psychotic features" specifier.
Individuals with psychotic depression experience the symptoms of a major depressive episode, along with one or more psychotic symptoms, including delusions and/or hallucinations. Delusions can be classified as mood congruent or incongruent, depending on whether or not the nature of the delusions is in keeping with the individual's mood state. Common themes of mood congruent delusions include guilt, persecution, punishment, personal inadequacy, or disease. Half of patients experience more than one kind of delusion. Delusions occur without hallucinations in about one-half to two-thirds of patients with psychotic depression. Hallucinations can be auditory, visual, olfactory (smell), or tactile (touch), and are congruent with delusional material. Affect is sad, not flat. Severe anhedonia, loss of interest, and psychomotor retardation are typically present.
Psychotic symptoms tend to develop after an individual has already had several episodes of depression without psychosis. However, once psychotic symptoms have emerged, they tend to reappear with each future depressive episode. The prognosis for psychotic depression is not considered to be as poor as for schizoaffective disorders or primary psychotic disorders.