Successful group psychotherapy of depression in adolescents alters fronto-limbic resting-state connectivity

•Affective and default mode regions show higher connectivity in adolescents with MDD.•Short-term group psychotherapy decreased connectivity between affective and default mode regions.•Amygdala connectivity changed along with depression severity.•Connectivity before treatment predicted therapy outcome.

BackgroundCurrent resting state imaging findings support suggestions that the neural signature of depression and therefore also its therapy should be conceptualized as a network disorder rather than a dysfunction of specific brain regions. In this study, we compared neural connectivity of adolescent patients with depression (PAT) and matched healthy controls (HC) and analysed pre-to-post changes of seed-based network connectivities in PAT after participation in a cognitive behavioral group psychotherapy (CBT).Methods38 adolescents (30 female; 19 patients; 13-18 years) underwent an eyes-closed resting-state scan. PAT were scanned before (pre) and after (post) five sessions of CBT. Resting-state functional connectivity was analysed in a seed-based approach for right-sided amygdala and subgenual anterior cingulate cortex (sgACC). Symptom severity was assessed using the Beck Depression Inventory Revision (BDI-II).ResultsPrior to group CBT, between groups amygdala and sgACC connectivity with regions of the default mode network was stronger in the patients group relative to controls. Within the PAT group, a similar pattern significantly decreased after successful CBT.Conversely, seed-based connectivity with affective regions and regions processing cognition and salient stimuli was stronger in HC relative to PAT before CBT. Within the PAT group, a similar pattern changed with CBT. Changes in connectivity correlated with the significant pre-to-post symptom improvement, and pre-treatment amygdala connectivity predicted treatment response in depressed adolescents.LimitationsSample size and missing long-term follow-up limit the interpretability.ConclusionsSuccessful group psychotherapy of depression in adolescents involved connectivity changes in resting state networks to that of healthy controls.