The use of transcranial pulsed electromagnetic fields in depression: A systematic review and meta-analysis
DOI: Pending DOI
Synopsis
Transcranial pulsed electromagnetic fields (T-PEMF) is an emerging treatment for depression, but the area of research is influenced by heterogeneity in both study and medical device designs. This study aims to examine the antidepressant effect of T-PEMF. Three broader categories of T-PEMF technology were identified. The preliminary findings from the random-effects meta-analysis, based on nine studies, suggest a small, but significant antidepressant effect of T-PEMF (SMD = -0,37, 95% CI -0,73 to -0,01) versus placebo. The subgroups did not show a statistically significant difference. The findings are limited by the heterogeneity in both the studies and the device designs used in the studies. Further research should focus on optimal stimulation parameters combined with standardized protocols.
Background
Novel therapeutic modalities for the treatment of depression are emerging, including T-PEMF (1). In contrast to transcranial magnetic stimulation (TMS), T-PEMF utilizes low-intensity electromagnetic fields which are far below the threshold for direct neural stimulation. The effects of T-PEMF on bone healing, arthritis and wound healing are described in the literature, however its antidepressant effects remain insufficiently examined (2). This field of research is characterized by a lack of consensus on stimulus parameters and device construction, which, together with an inconsistent use of terminology, makes it difficult to consolidate the knowledge and assess antidepressant efficacy. This review will use the term T-PEMF to describe this low intensity electromagnetic stimulation technique. The purpose of this systematic review and meta-analysis is to consolidate the evidence on the antidepressant effect of T-PEMF and examine possible moderating effects to inform and guide future developments in this area of research.
Methods
The systematic review and meta-analysis are being conducted following PRISMA guidelines (3). The study protocol was pre-published at PROSPERO (CRD420251030262). Embase, PubMed, SCOPUS, PsycINFO and clinicaltrials.gov were searched on February 6th, 2026, using a predefined search strategy. Backwards citation tracking was conducted on full-text-screened articles to identify other eligible studies. Additionally, publication lists of relevant articles were examined, and both study authors and device manufacturers were searched on clinicaltrials.gov. Studies were included if they 1) were randomized controlled trials (RCTs), 2) applied T-PEMF, and 3) included patients diagnosed with major depressive disorder or bipolar depression. At present, two independent reviewers are screening records, assessing risk of bias and extracting data. A random-effects meta-analysis on the standardized means will be conducted using the software RevMan (4).
The preliminary findings reported in this abstract are based on the extraction made by reviewer 1. The final results will be presented at the conference after comparing and resolving any discrepancies between reviewers 1 and 2.
Results
The primary search identified 1298 studies, an additional two studies were found through reference lists, three through authors’ publication lists and two through searches of the device manufacturers on clinicaltrials.gov. After the removal of 229 duplicates, 1076 records were moved to abstract-screening. Both reviewers assessed 27 articles relevant for full-text screening. Reviewer 1 considered 11 publications as eligible for inclusion in the review, additional information for two of these studies is currently being sought, which is why the preliminary analysis includes nine studies.
Across the nine studies, 369 patients received the intervention and 327 received placebo (1, 5, 6, 7, 8, 9, 10, 11, 12). Different devices were used across the studies, describing the technology as either T-PEMF, low field magnetic stimulation (LFMS) or synchronized TMS (sTMS). These terms are used as the names for the subgroups in the figure. The devices operated using low-intensity magnetic fields and had broadly comparable electromagnetic field strengths, but differed substantially in overall design, number of coils and coil placement. The preliminary findings indicate a statistically significant overall effect in favour of the intervention compared to a placebo (SMD =-0.37, 95% CI -0.73 to -0.01), as illustrated in the figure. None of the subgroups reached a statistically significant difference (LFMS SMD -0.52, 95% CI -1.1 to 0.06, T-PEMF SMD -0.19, 95% CI -0.57 to 0.2 and sTMS SMD -0.05, 95% CI -0.57 to 0.2) between the intervention group and the placebo, but all showed a small treatment effect favoring the intervention. Heterogeneity was absent between studies in the T-PEMF subgroup (I2=0 %), but high within the LFMS subgroup (I2=85 %). There was no statistically significant difference between the reported subgroup effects (x2=2.1, df =2, p=0.35, I2=4.7 %).
Discussion
The preliminary pooled analysis suggests a small antidepressant effect of T-PEMF, however, the findings should be interpreted cautiously. The included studies applied treatment using different medical devices, with comparable yet distinct stimulus parameters and designs. Furthermore, treatment duration (from a single session to 30 sessions) and session length (from 20 min to 1 h) varied substantially across studies, with some reporting acute antidepressant effects of the intervention and others a more subacute treatment response. Although none of the subgroup analyses reached statistical significance, the direction of the effects was consistent, suggesting a potential underlying therapeutic mechanism across modalities.
T-PEMF might provide a modest antidepressant effect. This area of research would benefit from a standardized treatment protocol and further research to determine e.g. optimal coil placement and stimulus parameters to support the future development of this treatment modality.
Disclosures
NBS has received an unrestricted grant to cover her salary as a part-time research assistant from February 2023 to January 2024 from MoodHeadBand Aps. NBS is conductinga RCT testing the MoodHeadBand, a new T-PEMF device. NBS has no equity in MoodHeadBand Aps or any other medical device firm.
The remaining authors have nothing to disclose.
References
1. Martiny, K., Lunde, M. & Bech, P. Transcranial low voltage pulsed electromagnetic fields in patients with treatment-resistant depression. Biol. Psychiatry 68, 163–169 (2010).
2. Rahbek, U. L., Tritsaris, K. & Dissing, S. Interactions of Low-Frequency, Pulsed Electromagnetic Fields with Living Tissue: Biochemical Responses and Clinical Results. Oral Biosciences and Medicine (2005).
3. Page, M. J. et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ n71 (2021) doi:10.1136/bmj.n71.
4. The Cochrane Collaboration. Review Manager (RevMan) . Preprint at (2020).
5. Dubin, M. J. et al. A double-blind pilot dosing study of low field magnetic stimulation (LFMS) for treatment-resistant depression (TRD). J. Affect. Disord. 249, 286–293 (2019).
6. Fava, M. et al. Double-blind, proof-of-concept (POC) trial of Low-Field Magnetic Stimulation (LFMS) augmentation of antidepressant therapy in treatment-resistant depression (TRD). Brain Stimul. 11, 75–84 (2018).
7. Rohan, M. et al. Low-Field Magnetic Stimulation in Bipolar Depression Using an MRI-Based Stimulator. American Journal of Psychiatry 161, 93–98 (2004).
8. Rohan, M. Multiple Treatment Study Using Low Field Magnetic Stimulation for Bipolar Depression (LFMS). https://clinicaltrials.gov/study/NCT01929681 (2017).
9. Rohan, M. L. et al. Rapid mood-elevating effects of low field magnetic stimulation in depression. Biol. Psychiatry 76, 186–193 (2014).
10. Pande, A. Low Field Magnetic Stimulation (LFMS) in Subjects With Treatment-Resistant Depression (TRD). https://clinicaltrials.gov/study/NCT02452892?tab=results (2017).
11. van Belkum, S. M. et al. No antidepressant effects of low intensity transcranial pulsed electromagnetic fields for treatment resistant depression. J. Affect. Disord. 294, 679–685 (2021).
12. Leuchter, A. F. et al. Efficacy and Safety of Low-field Synchronized Transcranial Magnetic Stimulation (sTMS) for Treatment of Major Depression. Brain Stimul. 8, 787–794 (2015).