T135. Hippocampal Subfield Volumes and Mixed Depression in Patients With Bipolar II Disorder

Abstract

Mixed depression (MxD) is common in bipolar disorder (BD) and associated with worse outcome. The DSM-5 task force coined a mixed feature specifier to include it not only in BDI, but also in BDII. Koukopoulos proposed and validated alternative criteria for MxD to enhance diagnostic sensitivity. There is a lack of studies of its neurobiology. Hippocampal subfields are specifically involved in emotion/mood regulation and in the mechanism of BD. Its role in MxD is unknown. We hypothesized that healthy controls (HCs) and groups of BDII patients subdivided on their lifetime MxD presence/absence would differ in hippocampal volumes.