I like these cold, gray winter days. Days like these let you savor a bad mood.

Snow storm, Hannibal and his army crossing the Alps, Joseph Mallord William Turner, 1812.

Mood-congruent and mood-incongruent delusions

In the 1980 DSM classification attention was directed to mood congruence of psychotic thoughts. If the patient’s delusional content was deemed depressive (e.g., low selfworth, guilt), the delusion was defined as congruent with the mood state and the patient was deemed as most lkely suVering from a mood disorder. If the delusional content was deemed ‘‘bizarre’’ (e.g., delusions of passivity), the delusion was defined as incongruent with the mood and the patient was considered to be schizoaVective or schizophrenic. Patients with an aVective syndrome with mood-incongruent as well as mood-congruent delusions, however, were allowed within the class of major depression.

In a review of the writings that supported a concept of a mood-incongruent psychotic mood disorder, three hypotheses were considered: it was a form of depressive illness, a subtype of a schizoaVective disorder, or a subtype of schizophrenia.

After reviewing the evidence of demographic studies, degree of risk in families of probands, laboratory test data, and treatment response, Kendler concluded that mood-incongruent psychotic depression was best viewed as a subtype of mood disorder and not as a feature of schizophrenia or schizoaVective disorder.

In an examination of the clinical, genetic, and prognostic significance of moodincongruentpsychotic symptoms, Abrams and Taylor (1983) further concluded that mood-incongruent psychotic symptoms did not identify a unique subpopulation of melancholic patients. In another large clinical study, the authors were unable to define diVerences in the congruence of delusions among patients classified as schizophrenia, schizoaVective disorder, psychotic, or mixed mania.

Neither a history of psychosis nor mood-incongruent delusions has prognosticsignificance for the treatment of bipolar depression.91 It is reasonable to conclude that mood congruence of desilusionssses not distinguish patients with a moods order from those with a non-mood disorder psychotic illness. Desilusions represents degrees of severity, not unique psychopathology.