Structural neuroimaging and mood disorders: recent findings, implications for classification, and future directions.

Neuroimaging is playing an increasing role in research of affective disorders, with investigators examining both volumetric changes of specific brain structures and vascular changes within white and gray matter. Recent studies have attempted to make clinical correlations between neuroimaging changes in unipolar and bipolar mood disorders. In this review, we focus particularly on those changes that are clinically meaningful. We conclude that there is enough evidence to begin to evaluate inclusion of neuroimaging findings in our mood disorder classification system. To this end, we propose two new mood disorder subtypes, vascular depression and vascular mania. Directions for future research in neuroimaging are then discussed.