Is Theta Burst Stimulation Ready as a Clinical Treatment for Bipolar Disorder?

Background: To date, no studies have investigated the efficacy of theta burst stimulation (TBS) in the treatment of bipolar disorder (BD), and the results are inconclusive.

Objective: We aim to systematically review the existing literature related to the efficacy of TBS in BD and synthesize the results through meta-analysis.

Methods: We searched for PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of science, PsycINFO, CNKI, and Wan fang databases without language restriction through July 30, 2023, and included randomized-controlled trials that assessed the treatment effect of TBS in patients with BD. We used a random-effects model to pool effect sizes, which were expressed as Cohen's d (or Odds ratio) and 95% confidence intervals (CIs). The outcome measures include changes in Montgomery-Asberg Depression Rating Scale (MADRS) scores, response and remission rates of depression, and dropout rates.

Result: Eight randomized sham-controlled trials were included in the meta-analysis. The overall effect size of the outcome measures, including changes in MARDS scale scores, response rate, and remission rates, were -0.81 (95% confidence interval [CI]: 4.07 to 2.44), 1.07 (95% CI: 0.47 to 2.44) and 0.74 (95% CI: 0.38 to 1.45), respectively. Notably, the TBS group showed favorable efficacy without major adverse events.

Conclusion: Current studies indicate that TBS does not show significant antidepressant efficacy in patients with BD, although it is very well tolerated.