Does transcranial magnetic stimulation have enough long-term follow-up evidence?

What does 'long-term' actually mean in TMS studies?

Long-term follow-up in TMS research typically ranges from 6 months to 5 years, but the definition varies widely by condition. For depression, a 2024 meta-analysis of accelerated TMS (aTMS) defined long-term as any follow-up after the acute treatment course; they found that depression scores at follow-up were significantly lower than immediately after treatment (standardized mean difference 0.22, meaning a small additional improvement), suggesting a 'long-term maintenance effect' [3]. In a 12-month study of multiple sclerosis patients, high-frequency TMS over the cerebellum produced balance improvements that continued to increase over the full year, with the Berg Balance Scale and walking tests showing significant gains at every measurement point [1]. For primary progressive aphasia, a 6-month randomized trial showed that active TMS slowed the decline in brain metabolism (standardized uptake value ratio 0.78 vs 0.77 in sham) and improved language scores by 7.7 points on the Mini Linguistic State Examination [2]. These timeframes are meaningful for chronic conditions, but they are still shorter than the 5-year or longer follow-ups common in other medical fields (e.g., cancer or cardiovascular trials).

Where is the long-term evidence strongest?

The strongest long-term evidence for TMS is in depression and obsessive-compulsive disorder (OCD). A 2024 meta-analysis of 14 studies (4 randomized controlled trials and 10 before-and-after studies) found that accelerated TMS for major depressive disorder not only produced rapid symptom improvement but also showed a maintenance effect at follow-up, with no significant difference in efficacy compared to standard TMS [3]. For OCD, a 2022 study of deep TMS reported that among 108 patients who responded to treatment, the average durability of response (time until a change in treatment was needed) was substantial, though the abstract does not give the exact number of months; importantly, the study notes that pharmacotherapy and cognitive behavioral therapy often show no durability, making TMS's durability notable [7]. In multiple sclerosis, a 12-month randomized trial with 43 patients showed that cerebellar TMS improved balance and walking speed, and these gains were accompanied by increased white matter integrity in brain tracts (fractional anisotropy increased significantly in both the cerebello-thalamo-cortical and cortico-ponto-cerebellar pathways) [1]. For adolescents with treatment-resistant depression, a 6-month open-label study of 66 participants found that 42% required retreatment with TMS, but those who completed the study had reduced depressive symptoms (mean Hamilton Depression Rating Scale-24 score of 5.24 at 6 months vs 8.21 at entry) [8].

Where is the long-term evidence still thin or missing?

For several conditions, long-term follow-up data are limited or absent. A 2025 systematic review of TMS for post-stroke hemiplegic shoulder pain included 11 studies with 584 patients and found that rTMS was significantly more effective than control for pain relief (standardized mean difference -1.14) and upper limb function (2.20), but the authors explicitly state that 'lack of long-term follow-up data restrict the generalizability of the results' [10]. For long COVID, a 2025 case series of only 5 patients reported trends toward improvement in fatigue, depression, and anxiety after accelerated TMS, but the follow-up was only immediate post-treatment, with no long-term data [9]. In geriatric depression, a 2021 review of 7 randomized controlled trials (total 260 patients) found response rates ranging from 6.7% to 54.3%, but the authors noted substantial variability in TMS dosage and a lack of long-term follow-up specific to older adults [5]. A 2025 survey of Norwegian psychiatrists found that 49% were unfamiliar with TMS, and 87% attributed its limited use to the method being 'relatively unknown,' indicating that clinical infrastructure for long-term follow-up is underdeveloped [6]. This gap is not unique to TMS: a 2023 commentary in The Lancet Global Health highlighted that in hypertension trials, a 5-year follow-up revealed that an initial benefit (5 mm Hg blood pressure reduction at 1 year) had reversed into harm (5 mm Hg increase) by 5 years, underscoring why long-term data are critical for any intervention [4].

About These Sources

This answer is built on 10 peer-reviewed studies — published from 2021 to 2025, 7 from 2024 or later, 3 in Q1 journals, collectively cited 131 times — selected as the most relevant from 15 studies that passed quality screening, drawn from 88 papers retrieved from a database of over 500 million.

Sources used in this answer

Related research questions