Treating Depression in Multiple Sclerosis with Transcranial Magnetic Stimulation: A Pilot Study

BACKGROUND: Depression is two to three times more common in people with multiple sclerosis (pwMS) than the general population. OBJECTIVE: To evaluate the efficacy and tolerability of intermittent theta burst stimulation (iTBS) in treating depressive symptoms in pwMS and major depressive disorder (MDD). METHODS: Twenty-one pwMS and MDD participated in an open-label 4-week trial of iTBS to the left dorsolateral prefrontal cortex (L-DLPFC). The Hamilton Depression Rating Scale (HAMD-17), California Verbal Learning Test Second Edition Total Learning (CVLT-II-TL), Brief Visuospatial Memory Test - Revised Total Learning (BVMT-R-TL) and Symbol Digit Modalities Test (SDMT) were administered before and after treatment. The primary outcome was response rates on HAMD-17, defined as a >50% reduction from baseline. RESULTS: Depression scores decreased from baseline to post-treatment with a mean reduction of 10.24 points (d = 1.55, 95% CI 0.83 to 2.25, P < .001). Ten (58.8%) pwMS responded to treatment, and seven (41.2%) were non-responders (n = 17). The treatment response group showed lower depression scores post-treatment than non-responders (d = -3.01, 95% CI -4.43 to -1.55, P < .001). Post-treatment, responders showed higher visuospatial memory (d = 1.11, 95% CI 0.06 to 2.14, P = .039) and information processing scores (d = 1.74, 95% CI 0.58 to 2.87, P = .003) compared to non-responders. There were two drop-outs, and two participants were lost to follow-up. There were no serious adverse events. CONCLUSIONS: iTBS can improve depressive symptoms in pwMS and MDD and may be associated with cognitive improvement. CLINICAL TRIAL REGISTRATION: NCT04621708.