Characterization of altered brain functional activity in patients with hypomania.

Hypomania, a diagnostic phase of bipolar disorder (BD), has garnered considerable research attention regarding its underlying neurobiological mechanisms, which remain inadequately understood. This cross-sectional observational study aimed to investigate the neurobiological correlates of hypomania by examining local brain activity and functional connectivity (FC) through resting-state functional magnetic resonance imaging (rs-fMRI) analyses. The results revealed abnormal local brain activity in the anterior orbital gyrus (OFCant) and superior frontal gyrus (SFG) in patients with hypomania. Additionally, FC analysis demonstrated disrupted connectivity between the right OFCant (R OFCant) and both the right putamen (R PUT) and right insula (R INS). Notably, these altered connectivity patterns showed significant correlations with clinical symptom severity. Collectively, these findings provide preliminary neuroimaging evidence for the neurobiological basis of hypomania, warranting replication and validation in larger and independent cohorts.