402. THE EFFICACY OF DEEP BRAIN STIMULATION OF COMBINED ANTERIOR LIMB OF INTERNAL CAPSULE AND NUCLEUS ACCUMBENS FOR TREATMENT-REFRACTORY OBSESSIVE-COMPULSIVE DISORDER: A RANDOMISED, DOUBLE-BLINDED, AND SHAM-CONTROLLED STUDY

Abstract Background OCD is a treatment-resistant mental disorder, with a significant portion of patients not responding to first-line treatments. Deep brain stimulation (DBS) has emerged as a promising therapeutic approach for treatment-refractory OCD. Aims & Objectives We assessed the efficacy and safety of a novel combined anterior limb of internal capsule and nucleus accumbens DBS (ALIC-NAc DBS) for treatment-refractory OCD. Method This is a randomised, double-blind, sham-controlled study. Participants were diagnosed with OCD, aged between 18 and 65 years, with a Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score of at least 25. Participants were eligible if undergone adequate trials of at least three first- or second-line medications, combined with at least two augmenting agents, and had received a full course of cognitive-behavioral therapy. Participants were randomly assigned to the active DBS or the sham DBS group for a three-month double-blind treatment phrase. Subsequently, they underwent a 3-month open-label treatment phase, during which participants in both active and sham DBS groups received active stimulation. Results Twenty-four patients who met the criteria were recruited and randomly assigned to the active DBS group (n = 12) or sham DBS group (n = 12). For primary outcome, at the 3-month follow-up, 5 participants in the active DBS group (41.7%) and no participant in the sham DBS group responded to treatment, indicating a significant difference (p = 0.047). For secondary outcome, at the 3-month follow-up, the mean Y-BOCS score decreased by 8.58 points (SD 3.86, reduction rate 29.4%) in the active DBS group and by 1.00 points (SD 6.00, reduction rate 3.08%) in the sham DBS group, showing a significant difference between the groups (95% CI 3.32–13.17, p = 0.002). At the 6-month follow-up, after the sham stimulation group had received three months of active stimulation, there was no longer a significant difference in the mean Y-BOCS score reduction between the two groups. A similar trend was observed for the Hamilton Anxiety Scale, Hamilton Depression Scale and Clinical Global Impressions scores. No serious adverse event related to the device occurred. Discussion & Conclusions Our study demonstrated the efficacy and safety of ALIC-NAc DBS for OCD, providing a promising treatment option for treatment-refractory OCD.