MRI analysis of cerebellar vermal abnormalities in bipolar disorder.

OBJECTIVE The authors sought to expand previous findings of vermal abnormalities in bipolar disorder patients. METHOD Magnetic resonance imaging (MRI) morphometry was used to quantify vermal subregion volumes in 18 subjects with first-episode bipolar disorder, 21 subjects with multiple-episode bipolar disorder, and 32 healthy subjects. RESULTS Vermal subregion V2 volume was significantly smaller in multiple-episode bipolar disorder subjects than in first-episode patients and healthy subjects. Vermal subregion V3 was significantly smaller in multiple-episode bipolar disorder subjects than in healthy subjects. CONCLUSIONS These results suggest that posterior-inferior cerebellar vermal abnormalities are present in patients with multiple-episode bipolar disorder.