Alterations in the neural correlates of affective inhibitory control following cognitive behavioral therapy for depression: A Canadian biomarker integration network for depression (CAN-BIND) study

Background: Cognitive behavioral therapy (CBT) is an efficacious treatment for depression. CBT may in part exert its therapeutic effect by strengthening inhibitory control (IC). However, the relationship between CBT and IC has yet to be thoroughly explored; in particular, it is not clear whether IC is modulated following a course of CBT. Methods: Forty-one adults with depression were recruited to undergo sixteen weeks of CBT; data from twenty-five healthy controls were used for baseline comparisons. Participants completed an affective Go/No-go task, a measure of IC, while undergoing electroencephalography recording. Electroencephalography measures of interest were the event-related potential (ERP) N2 and P3 components. Results: At baseline, individuals with depression exhibited greater ERP amplitudes during the N2 regardless of affective condition; source reconstruction attributed this to patients exhibiting greater activity in the superior frontal gyrus, right temporal lobe, and anterior cingulate cortex (ACC). Following treatment, the ERP amplitude during the N2 component decreased for angry stimuli but increased for happy stimuli. Source reconstruction attributed ERP changes in the angry-condition to the left occipital and fusiform gyrus, and changes in the happy-condition to regions including the superior frontal gyrus and ACC. Limitations: There was no placebo-treatment group. Conclusions: Neural correlates of the affective Go/No-go task were altered in depression and were found to be selectively modulated over the course of CBT in a condition- and region-specific manner. These findings support the notion that the modulation of IC may be one of the potential therapeutic mechanisms of CBT in the treatment of depression.