Is Transcranial Magnetic Stimulation (TMS) an Effective Therapy in Reducing Depressive Symptoms in Adults with Bipolar Depression?

OBJECTIVE: The objective of this selective EBM review is to determine whether or not transcranial magnetic stimulation (TMS) is an effective therapy in reducing depressive symptoms in adults with bipolar depression. STUDY DESIGN: Systematic review of three randomized controlled trials (RCTs) that were published in the English language between 2016 and 2019. DATA SOURCES: Data sources included articles found using PubMed as the search engine and were selected based on their relevance to the research question as well as patient measured outcomes. OUTCOMES MEASURED: Outcomes measured include changes in depression symptoms measured using the 17-item Hamilton Depression Rating Scale (HDRS-17) and Modified 24-item Hamilton Depression Rating Scale (HDRS). RESULTS: Tavares et al. found that 48% of patients with bipolar depression receiving active TMS were treatment responders with a numbers needed to treat (NNT) of 5. Yang et al. showed no differences in HDRS scores between groups at baseline and follow-up as shown by p=0.451 and F-score of 0.577. Finally, Fitzgerald et al. demonstrated a mean change from baseline of 3.4 in the active group and mean change from baseline of 3.0 in the sham group. While both are significant changes, there is no significant change between treatment groups at the conclusion of the 4 week study. CONCLUSIONS: Even though the study by Tavares et al.1showed a significant improvement with TMS in depressive symptoms in adults with bipolar depression, the other two studies by Yang et al. and Fitzgerald et al. demonstrated no difference between treatment groups. Based on these conflicting findings, the results from this systematic review are inconclusive. Thus, further research is needed that includes sufficiently larger sample sizes and longer treatment trials