Static and dynamic functional connectivity of the amygdala and serotoninergic activity following bright light in subthreshold depression

Motivation: The presence of subthreshold depression significantly increases the likelihood of developing major depressive disorder and is linked to a higher burden of illness and suicide risk. Goal(s): The objective of this clinical trial was to evaluate the relationship between BLT and the functional connectivity (FC) alterations of the amygdala, as well as the serotoninergic distribution in subthreshold depression. Approach: Subthreshold depression subjects were randomly divided into two groups: the BLT group and the placebo group. Results: BLT group showed increased sFC of right basolateral amygdala (BLA)/superficial amygdala (SFA)-right middle temporal gyrus and dFC of right centralmedial amygdala and right inferior orbital frontal gyrus. Impact: These findings indicated that BLT could relieve depressive symptoms and alter FC of the amygdala in subthreshold depression (StD). Combining baseline sFC and dFC of the amygdala may have the potential to assess the effectiveness of BLT in treating StD.