Abstract

OBJECTIVE:

A substantial number of manic episodes include conspicuous depressive symptoms. Manic episodes have been clinically classified a posteriori using preset criteria. The aim of this study was to investigate the possibility that there might be a natural division of manic episodes into clinical types.

METHOD:

One hundred and five inpatients met Research Diagnostic Criteria and DSM-III-R criteria for manic episodes and were rated before institution of pharmacological treatment. The authors conducted a factor analysis of 37 behavior rating items from the Schedule for Affective Disorders and Schizophrenia. The resulting factors were used as independent variables in a cluster analysis of the patients.

RESULTS:

This analysis revealed four factors corresponding to manic activation, depressed state, sleep disturbance, and irritability/paranoia. Cluster analysis separated the patients into two groups. One included patients with major depressive disorder and mania. Blind, a priori clinical classification into classic and mixed mania (mania plus depression) showed that all of the patients in the depressed cluster, and about 40% of those in the nondepressed cluster, were in a mixed state according to clinical criteria. Comparison of the clinically mixed and nonmixed patients in the nondepressed cluster revealed that the mixed patients in that cluster had higher scores for items related to anger, worry, dysphoria, and irritability.

CONCLUSIONS:

These data suggest that manic episodes can be naturalistically classified as classic (predominately euphoric), dysphoric, or depressed.