Repetitive Transcranial Magnetic Stimulation as Maintenance Treatment of Depression: The MAINT-R Randomized Clinical Trial.

Importance: Depression relapse poses significant medical and economic challenges. Repetitive transcranial magnetic stimulation (rTMS) as maintenance treatment may prevent relapse of treatment-resistant depression (TRD). Objective: To compare the effectiveness between low-frequency rTMS and lithium in preventing TRD relapse. Design, Setting, and Participants: This randomized clinical trial was conducted from September 1, 2018, to May 31, 2023, at Keio University Hospital and Shinjuku-Yoyogi Mental Lab Clinic, Tokyo, Japan, among 75 participants with TRD aged 18 years or older with moderate-to-severe depressive symptoms despite at least 2 adequate antidepressant treatments who subsequently responded to an acute course of bilateral rTMS. Interventions: Participants were randomly assigned at a 1:1 ratio to receive right dorsolateral prefrontal 1-Hz rTMS (24 weekly sessions; 120% of the resting motor threshold, 900 pulses in 15 minutes) or 24-week maintenance treatment with lithium pharmacotherapy. Participants were maintained on the same venlafaxine dose (150-225 mg/d) as the acute-phase dose. Main Outcomes and Measures: The primary outcome was the between-group difference in baseline-adjusted Montgomery-Åsberg Depression Rating Scale (MADRS) scores (range, 0-60, where 0 indicates no symptoms and 60 indicates most severe symptoms) at week 24, which was analyzed using a linear mixed-effects model for repeated measures in an intention-to-treat sample. The secondary outcome was the time to relapse (defined as a MADRS score ≥22), which was analyzed using Kaplan-Meier survival curves. Adverse events were also compared between groups. Results: Among the 75 participants, 38 were assigned to the rTMS group (mean [SD] age, 44.1 [11.7] years; 21 male participants [55.3%]; baseline mean [SD] MADRS score, 8.9 [4.7]), and 37 were assigned to the lithium group (mean [SD] age, 44.1 [11.1] years; 19 male participants [51.4%]; baseline mean [SD] MADRS score, 7.9 [4.5]). There was no significant between-group difference in the primary outcome at week 24 (0.3 points [95% CI, -2.7 to 3.3 points]; P = .84). Survival analysis showed no meaningful between-group difference in relapse rates. During the 24-week maintenance phase, there were 7 patients who relapsed in each group. There was a higher number of adverse events among participants in the lithium group (n = 16) than in the rTMS group (n = 3; odds ratio, 7.10 [95% CI, 1.84-27.49]; P = .005). Conclusions and Relevance: In this randomized clinical trial, low-frequency rTMS of the right prefrontal cortex as maintenance treatment showed comparable efficacy, as well as better safety and tolerance, compared with lithium. Maintenance low-frequency rTMS could be a promising relapse prevention strategy for patients with TRD. Trial Registration: Japan Registry of Clinical Trials: jRCTs032180188.