Repetitive transcranial magnetic stimulation versus electroconvulsive therapy for major depression: a meta-analysis of stimulus parameter effects.

BACKGROUND

Studies comparing the antidepressant effects of electroconvulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS) have reported mixed results, as the choice of rTMS stimulus parameters is essential to its antidepressive effect. This meta-analysis aimed at assessing how rTMS stimulus parameters influence the efficacy of rTMS relative to ECT in treating major depression.

METHODS

A comprehensive literature search (including PubMed, CCTR, Web of Science, Embase, EAGLE, NTIS, CBM-disc, CNKI, Current Controlled Trials, Clinical Trials, International Clinical Trials Registry, and Internet Stroke Center) was conducted dating until December 2012. After exclusion of low-quality studies, the key search terms ('depressive', 'depression', 'transcranial magnetic stimulation', 'TMS', 'repetitive TMS', 'electroconvulsive therapy', and 'ECT') produced nine high-quality randomized controlled trials (RCTs) of rTMS versus ECT.

RESULTS

These nine studies, composed of 395 patients, were meta-analyzed through assessment of odds of remission, response, and drop-out. Two rTMS subgroups displayed non-significant superiority to ECT: 20 Hz (odds ratio (OR) = 1·20; P > 0·05) and ≥ 1200 daily stimuli (OR = 1·06; P > 0·05). One rTMS subgroup displayed non-significant inferiority to ECT: four-week treatment period (OR = 0·65; P > 0·05). The other rTMS subgroups were significantly inferior to ECT. Repetitive transcranial magnetic stimulation was associated with a 30% relative reduction in the odds of drop-out, however non-significantly (95% confidence interval (CI), 0·36-1·39).

DISCUSSION: The results indicate that the efficacy of rTMS is tied to its stimulus parameters. Varying stimulus parameters can result in varying antidepressive effects. Consequently, future research on rTMS or rTMS versus ECT should take the influence of rTMS stimulus parameters into consideration.