Electroconvulsive therapy induces cortical and subcortical structural changes in adolescents with major depressive...

Although electroconvulsive therapy (ECT) is an effective intervention for adolescents with major depressive disorder (MDD), the underlying neuroanatomical mechanisms remain poorly understood. This structural magnetic resonance imaging (sMRI) study investigated cortical and subcortical morphology in adolescents with MDD and suicidal ideation before and after ECT.

The study included 27 adolescent MDD patients with suicidal ideation and 31 demographically similar healthy controls (HC). Cortical thickness, surface area, and subcortical volumes were quantified from MRI scans using the FreeSurfer. General linear models and linear mixed models were employed to evaluate morphological differences between patients and HCs at baseline, as well as longitudinal changes in patients following ECT. Partial correlation and multiple regression analyses further explored associations between structural alterations and symptom improvement.

At baseline, MDD patients showed widespread morphological deficits within the cingulate-insula-dorsolateral prefrontal cortical circuit and subcortical regions including the hippocampus and thalamus. Following ECT, significant structural increases were observed in the hippocampus, amygdala, insula, and dorsolateral prefrontal cortex. Subcortical volumetric changes were not linearly associated with symptom improvement, while dorsolateral prefrontal alterations were negatively correlated with changes in suicidal ideation.

ECT partially reversed baseline cortical-subcortical structural deficits in patients, particularly in the insula, dorsolateral prefrontal cortex (DLPFC), and hippocampus. Structural alterations in the DLPFC may be associated with the alleviation of suicidal ideation, whereas no significant linear relationships were observed between subcortical volumetric changes and symptom improvement.