Objective: To validate and clinically characterize mixed bipolar states derived from the concepts of Kraepelin and the Vienna School and defined as sustained instability of affective manifestations of opposite polarity--that usually fluctuate independently of one another--in the setting of marked emotional perplexity.
Method: Our criteria for mixed states represent a modified "user-friendly" operationalization of these classical concepts. We compared 143 mixed state patients, so defined, with 118 DSM III-R manic patients, systematically evaluated with the Semistructured Interview for Depression (SID) in our in-patient and day-hospital facilities.
Results: The two groups were comparable from demographic and familial standpoints (including family history for bipolar disorder). Mixed states were predominant in the past history of index mixed patients who were more likely to have experienced stressors and to have attempted suicide; manic and hypomanic episodes were more common in the past history of the index manic patients who, in addition, had more episodes and hospitalizations. Although rates of chronicity and rapid cycling were not significantly different in the two groups, the modal episodes in the mixed states were 3-6 months, and in mania they were less than 3 months. Two thirds of both groups arose from a dysregulated baseline temperamental dysregulation, which in manics, was largely hyperthymic, and in mixed patients, was both hyperthymic and depressive. Of our 143 mixed states, only 54% met the DSM III-R criteria for mixed states (which conformed to "dysphoric mixed mania"); of the remaining, 17.5% could be described as "mixed agitated psychotic depressive states" with irritable mood and flight of ideas, and 26% as "unproductive-inhibited manic" with fatigue and indecisiveness. The family history and course of these "non-DSM III-R" mixed states were essentially similar to DSM III-R mixed states.
Limitation: Family history could not be obtained blind to clinical status in patients with severe psychotic mood states.
Clinical relevance: These data favor the classical European approach to mixed states over the grossly under-inclusive current official diagnostic systems.
Conclusion: The phenomenology of mixed states is more than the mere superposition of opposite affective symptoms and, in many instances, it represents an expansive-excited phase intruding into a depressive temperament, and a melancholic episode intruding into a hyperthymic temperament.