Exploratory meta-analysis on deep brain stimulation in treatment-resistant depression.

OBJECTIVE Deep brain stimulation is currently an experimental treatment for major depressive disorder. Information is lacking, however, on how sham responding may affect efficacy. This article applies exploratory meta-analysis to address that topic. METHODS Data on benefits of deep brain electrical stimulation come from a recent review. Stimulated brain regions included subgenual cingulate, capsular interna, nucleus accumbens, and medial forebrain bundle. Expert opinion plus random number software was used to generate hypothetical values for sham responding. RESULTS An effect size of 1.71 (95% CI: 1.47-1.96) was obtained for deep brain stimulation versus sham treatment in patients suffering from long-term treatment-resistant depression. CONCLUSION Preliminary findings on deep brain electrical stimulation suggest that the procedure may be 71% more effective than sham treatment. Expressing these findings as patients-needed-to-treat, deep brain electrical stimulation is required by 2.9 patients with long-term treatment-resistant depression in order for one of them to benefit.