Transcranial magnetic stimulation in the treatment of mood disorder: A review and comparison with electroconvulsive therapy

Objective: To review repetitive transcranial magnetic stimulation (rTMS) as a mode of therapy for depression. Method: The following aspects of rTMS were reviewed and compared with elect roconvulsive therapy (ECT): history, basic principles, technical considerat ions, possible mode of action, safety, adverse effects, and effects on mood in both healthy individuals and those suffering from bipolar disorder (BD) or depression. Results: rTMS may selectively increase or decrease neuronal activity over d iscrete brain regions. Asa result of this focused intervention with TMS, th e potential for unwanted side effects is substantially reduced, compared wi th ECT. In open trials, rTMS and ECT are reported to be equally efficacious for patients having depression without psychosis, but the therapeutic bene fits reported in double-blind sham-rTMS controlled trials are more modest. Conclusion: The antidepressant and antimanic effects of rTMS depend on tech nical considerations such as stimulus frequency, intensity, and magnetic co il placement, which may not yet be optimized. Biological heterogeneity amon g the patients treated with rTMS may also contribute to differing efficacy across clinical trials. rTMS may possess tremendous potential as a treatmen t for mood disorder, but this has not yet been realized. rTMS must still be regarded as an experimental intervention requiring further refinement.