Amygdala functional connectivity and response to aerobic exercise in subthreshold depression-an exploratory fMRI study
摘要
Aerobic exercise (AE) has emerged as a promising non-pharmacological intervention for depression. However, the extent to which AE can alleviate depressive symptoms varies across individuals, and the neural or clinical factors that relate to treatment response remain incompletely understood. This study aimed to investigate whether baseline amygdala-based functional connectivity (FC) is associated with symptom improvement following AE and identify neural correlates of treatment responsiveness.
MethodsForty-three participants with subthreshold depression (StD) completed an AE intervention and were classified as remitters (n = 21) or non-remitters (n = 22) based on post-AE Patient Health Questionnaire-9 (PHQ-9) scores. Resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired at baseline and after the intervention. Group comparisons and partial correlation analyses were conducted to assess associations between amygdala-based FC and depressive symptom outcomes.
ResultsBaseline left amygdala FC was positively correlated with post-AE PHQ-9 scores in the right precuneus and bilateral middle frontal gyrus (MFG), and negatively correlated with changes in PHQ-9 (ΔPHQ-9) scores in the left precuneus and left MFG. Additionally, remitters showed reduced FC between the left amygdala and left supplementary motor area (SMA) compared to non-remitters. Baseline right amygdala FC was positively correlated with post-AE PHQ-9 scores in the left inferior parietal lobe (IPL), right middle temporal gyrus (MTG), left superior medial frontal gyrus (mSFG) and left MTG, but there were no significant findings for ΔPHQ-9 or group differences. An exploratory analysis combining bilateral amygdala FC and clinical variables yielded high classification accuracy within the same sample (AUC = 0.93). A significant group effect was also observed in the right MTG for left amygdala FC, though no group × time interaction emerged.
ConclusionsBaseline amygdala FC is associated with symptom improvement during AE in StD. These exploratory findings suggest that amygdala connectivity may play a role in treatment responsiveness.
Clinical trial numberNot applicable.