Background: Although included in successive editions of the DSM since its introduction in the IIIrd, the subtyping of manic episode into 'with mood-congruent (MCP) versus mood-incongruent (MIP) psychotic features' is yet to be fully validated.
Methods: One thousand and ninety consecutive manic patients were recruited at 19 medical centers in France from December 2000 to April 2002. Patients were systematically assessed for sociodemographic characteristics, illness course, phenomenology and had to fill out biphasic mood charts during the first study week.
Results: Five hundred forty-four manic patients were psychotic, 364 (33.4%) being MCP, 180 (16.5%) MIP. Although both groups scored high on the Mania Rating Scale, MIP patients had significantly more often been diagnosed as schizophrenic, or anxiety disorders, with long delays to first diagnosis as bipolar disorder. MIP were also significantly different in a variety of domains: 2:1 female/male ratio; shorter free intervals between episodes; more auditory hallucinations, reference, persecutory and somatic delusions; more stressors; more anger; higher depression scores and diurnal variation of mood, as well as anxious symptoms and hyperemotionality upon improvement.
Conclusions: MCP and MIP manias occurred in nearly half of this largest sample of manic patients ever reported. As postulated 150 years ago by Falret and Baillarger in France, free intervals, characterize both forms of circular insanity. Both are prevalent and severe remitting forms of mania, but the latter differs from the former by much shorter free intervals, greater instability of mood and mixed anxious-depressive features. This is compatible with the Vienna School hypothesis that dysphoric instability of the patient may induce emotional reactions in significant others, which, in turn, might lead to extremely paranoid and psychotic symptom formation of the MIP type in manic patients. From a phenomenologic perspective--arising understandably from emotional processes-these considerations would place MIP mania more in the circular affective rather than in the schizophrenic domain.