Deep brain stimulation of the superolateral medial forebrain bundle in obsessive-compulsive disorder: Outcomes of symptom domains and their predictive value for treatment efficacy

Deep Brain Stimulation (DBS) of the superolateral medial forebrain bundle (slMFB) has shown promise in treatment-resistant obsessive-compulsive disorder (OCD). However, little is known about whether specific symptom domains respond better to the intervention or whether they may predict overall treatment outcomes. This study evaluated the effects of slMFB DBS on self-reported obsessive-compulsive symptom domains and investigated whether baseline symptom domains predict clinical response. Fourteen patients with treatment-resistant OCD received slMFB DBS. Symptom severity was assessed with the Obsessive-Compulsive Inventory-Revised (OCI-R) and the Yale-Brown Obsessive-Compulsive Scale at multiple postoperative time points. Linear mixed-effects models examined longitudinal changes, and stepwise multiple regression analyses tested whether baseline symptom proportions predicted treatment response. OCI-R total scores decreased significantly over time (F = 16.80, p < .001, p FDR = .004), with large effect sizes ( d = −1.19 at last follow-up). Subscale analyses revealed the greatest improvements in obsessing, checking, and ordering. Regression analyses identified the baseline proportion of obsessing symptoms as a significant predictor of outcome (β = 0.55, p = .043, R 2 = 0.30). slMFB DBS yields substantial improvement in self-reported obsessive-compulsive symptoms, particularly in patients with prominent obsessional features. Obsession-dominant profiles may predict superior response, supporting a phenotype-guided approach to neuromodulation in OCD.