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

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.

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

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.

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.

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