Modulation of cerebellar homotopic connectivity by modified electroconvulsive therapy at rest: Study of first-episode, drug-naive adolescent major depressive disorder.

Previous studies of brain function alterations that are associated with modified electroconvulsive therapy (MECT) for major depressive disorder (MDD) have yielded conflicting results because of variations in treatment durations, types of antidepressants, and disease course. Consequently, predicting the efficacy of MECT remains challenging. Thirty patients with first-episode, drug-naive adolescent MDD and 34 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging and neuropsychological tests. The patients received MECT and underwent scanning at two time points (baseline and posttreatment). Voxel-mirrored homotopic connectivity (VMHC), support vector machine (SVM), and support vector regression (SVR) analyses were employed to analyze the imaging data. Compared with HCs, patients at baseline exhibited greater VMHC in the cerebellum_2 and cerebellum_8. Following treatment, patients exhibited the restoration of normal VMHC values. Additionally, SVM and receiver operating characteristic curve analyses revealed that VMHC values in the cerebellum_2 could differentiate MDD patients from HCs with 73.85 % accuracy, 70.00% sensitivity, 79.41 % specificity, and an area under the curve of 0.7486. Furthermore, the SVR results indicated a significant association between predicted and actual symptomatic improvement based on the reduction ratio of Hamilton Depression Rating Scale-17 total scores (R2 = 0.5269, P < 0.0001). This study provides evidence that MECT modulates homotopic connectivity of the cerebellum_2 in first-episode, drug-naive adolescent MDD. Moreover, VMHC values in the cerebellum_2 may serve as a valuable neuroimaging biomarker for distinguishing MDD from HCs and potentially predicting early treatment response in MDD.