A magnetic resonance imaging study of mood stabilizer- and neuroleptic-naïve first-episode mania

Objectives: Patients with bipolar disorder have changes in brain structures but it is unclear if these are present at disease onset and thus predispose subjects to develop the disorder, or whether they develop during the course of the disorder, either due to the effects of multiple episodes or as a consequence of treatment with psychotropic agents. Studies in first-episode (FE) manic patients have the potential to provide answers to these questions. Methods: Voxel-based morphometry (VBM) was used to assess magnetic resonance imaging scans of 15 FE manic patients and 15 matched healthy controls. Results: Using a priori defined statistical criteria, no significant differences in brain structures were noted between the two groups. However, there was approximately a 6% reduction in left anterior cingulate, left precuneus and right posterior cingulate volume in FE patients and these reductions were significant (p ≤ 0.002) at uncorrected levels. Conclusions: First-episode manic patients have reductions in left anterior, right posterior cingulate as well as left precuneus volumes, but these reductions are smaller and likely worsen with further mood episodes in bipolar patients.