Gamma activity model for treatment-resistant bipolar psychotic mania.

Objectives: The objective was to investigate the effect of clozapine on spontaneous gamma activity in treatment-resistant bipolar psychotic mania. Methods: Patients with treatment-resistant (TR) bipolar psychotic mania on clozapine monotherapy and nontreatment-resistant bipolar psychotic mania patients receiving lithium were prospectively studied for 6 weeks on severity of psychopathology and 30-49 Hz gamma spectral power. Results: Spectral power significantly increased in the lithium group and decreased in the clozapine group; no within group significant difference found. Conclusions: We propose a model highlighting the role of gamma spectral power and modulations of GABAergic neurotransmission in TR bipolar psychotic mania. [ABSTRACT FROM AUTHOR]