Deep brain stimulation for obsessive-compulsive-disorder: a systematic review and meta-analysis of individual participant outcome data from sham-controlled trials

Deep brain stimulation (DBS) is a neurosurgical intervention for severe, treatment-refractory obsessive-compulsive disorder (OCD). Here, we conducted the first meta-analysis using individual participant outcome data, comparing DBS to sham-stimulation in randomized controlled trials (RCTs), and systematically evaluated adverse events and methodological trial quality. We conducted a comprehensive systematic search in multiple databases and included randomized-controlled trials comparing DBS with sham in adult patients with OCD. We obtained YBOCS data for individual participants and performed a two-stage random-effects meta-analysis. Nine RCTs with small sample sizes were included, resulting in a total sample of 91 patients. Meta-analysis of showed a decrease of 5.1 YBOCS points in favor of DBS compared to sham (95% confidence interval (CI) 2.3 – 7.9, 0.56 Hedges’ g). OR was 5.7, 95% CI 2.2 - 15), with a NNT of 3.3. Efficacy of studies that optimized DBS parameters was much higher than that of non-optimized studies (beta 5.1, 95% CI 0.59 – 9.5, p-value 0.026). Adverse events occurred during surgery, active and sham trial phases, and follow-up, with hypomania and cognitive problems being the most frequently reported stimulation-related adverse events. Concluding, we found a significant effect of DBS compared to sham in treating OCD, especially after DBS parameter optimization. However, the quality of evidence was low, and heterogeneity was high. More rigorous sham-controlled evidence could further improve credibility of DBS for OCD.