Emerging Outlook on Personalized Neuromodulation for Depression: Insights From Tractography-Based Targeting

Abstract

BackgroundDeep brain stimulation has shown promise in treating individual patients with treatment-resistant depression, but larger-scale trials have been less successful. Here, we created what is, to our knowledge, the largest meta-analysis with individual patient data to date to explore whether the use of tractography enhances the efficacy of deep brain stimulation for treatment-resistant depression. MethodsWe systematically reviewed 1823 articles, selecting 32 that contributed data from 366 patients. We stratified the individual patient data based on stimulation target and use of tractography. Using two-way type III analysis of variance, Welch’s two-sample t tests, and mixed-effects linear regression models, we evaluated changes in depression severity 1 year (9–15 months) postoperatively and at last follow-up (4 weeks to 8 years) as assessed by depression scales. ResultsTractography was used for medial forebrain bundle (MFB) (n = 17/32), subcallosal cingulate (SCC) (n = 39/241), and ventral capsule/ventral striatum (n = 3/41) targets; it was not used for bed nucleus of stria terminalis (n = 11), lateral habenula (n = 10), and inferior thalamic peduncle (n = 1). Across all patients, tractography significantly improved mean depression scores at 1 year (p < .001) and LFU (p = .009). Within the target cohorts, tractography improved depression scores at 1 year for both MFB and SCC, though significance was met only at the α = 0.1 level (SCC: β = 15.8%, p = .09; MFB: β = 52.4%, p = .10). Within the tractography cohort, patients with MFB tractography showed greater improvement than patients with SCC tractography (72.42 ± 7.17% vs. 54.78 ± 4.08%) at 1 year (p = .044). ConclusionsOur findings underscore the promise of tractography in deep brain stimulation for treatment-resistant depression as a method for personalization of therapy, supporting its inclusion in future trials.