Subject terms
mood disorders
Bright light exposure (BL) induces neurogenesis in the rat hippocampal dentate gyrus (DG). We had previously conducted a randomized controlled trial (RCT) in which a 4-week period of BL in healthy participants resulted in increased volume of the left DG-head. This study aimed to investigate the effects of BL on the DG in patients with mood disorders. A 4-week RCT was conducted in which patients with mood disorders were randomly assigned to either a BL group (10,000 lx) or dim light exposure group (DL group; 50 lx). All patients underwent clinical assessment and magnetic resonance imaging at baseline and after the intervention. The study registration number is UMIN000019220. Our final sample included 24 patients (BL group, 