Neurobiological correlates of CBT response in OCD through the analysis of resting state networks.

Obsessive-compulsive disorder (OCD) is a psychiatric condition characterized by obsessions and compulsions that cause significant distress and functional impairment. Cognitive-behavioral therapy (CBT), particularly involving exposure and response prevention (ERP), is a first-line treatment for OCD, though patient response varies widely. This study investigates the neurobiological correlates of CBT response in OCD, focusing on resting-state functional connectivity (rsFC) alterations. Twenty-five patients with OCD and 26 matched controls underwent resting-state fMRI at baseline and post-CBT. Results indicated decreased rsFC at baseline in OCD patients compared to controls within the higher visual (HVN), posterior salience (PSN), and language networks (LN). Following CBT, patients showed increased HVN connectivity, suggesting a normalization of the rsFC within this network. Additionally, we found an association between baseline LN rsFC and symptom improvement after CBT (the higher the connectivity, the more the symptom improvement), suggesting that LN connectivity could be a predictor of treatment response. These findings emphasize the role of sensory processing networks in OCD and highlight the ability of CBT to modulate brain connectivity.