Eating disorders, including Anorexia Nervosa (AN) and Bulimia Nervosa (BN), are complex mental health conditions that pose significant threats to physical and psychological well-being. Despite advancements in traditional treatments such as cognitive-behavioral therapy and medication, many patients struggle to achieve lasting remission. In recent years, Transcranial Magnetic Stimulation (TMS) has emerged as a promising non-invasive alternative, with growing research supporting its efficacy and safety. Two recent systematic reviews and analyses, published in peer-reviewed journals, shed critical light on the potential of TMS in transforming the treatment landscape for these devastating disorders (Chmiel et al., 2024; Bahadori et al., 2024).
Understanding the Burden of Eating Disorders
Before delving into the role of TMS, it’s essential to acknowledge the profound impact of AN and BN. AN, characterized by restrictive eating, intense fear of weight gain, and distorted body image, has one of the highest mortality rates among mental illnesses. BN, on the other hand, involves recurrent episodes of binge eating followed by compensatory behaviors like self-induced vomiting or excessive exercise, leading to electrolyte imbalances, dental issues, and emotional distress. For a significant subset of patients, standard treatments fail to address core symptoms, highlighting the urgent need for innovative therapeutic approaches.
TMS: How Does It Work?
TMS is a non-invasive neurostimulation technique that uses magnetic pulses to modulate neural activity in specific regions of the brain. By targeting areas associated with mood, cognition, and eating regulation—such as the Dorsolateral Prefrontal Cortex (DLPFC) and Dorsomedial Prefrontal Cortex (DMPFC)—TMS aims to restore balance to dysfunctional brain networks. Unlike invasive procedures like deep brain stimulation, TMS requires no surgery or anesthesia, making it a more accessible option for many patients. Repetitive TMS (rTMS), a variant that delivers repeated magnetic pulses, is the most commonly used form in eating disorder research due to its ability to induce long-lasting neural plasticity (Chmiel et al., 2024).
rTMS for Bulimia Nervosa: Efficacy, Safety, and Mechanisms
A 2024 systematic review by Chmiel et al. (2024) focused on the use of rTMS for BN, addressing gaps in previous research that lacked specificity to single stimulation methods or eating disorder subtypes. The team conducted a comprehensive search of databases including PubMed/Medline and ResearchGate, spanning from 2000 to 2024, and included 12 qualifying studies—encompassing randomized controlled trials (RCTs), pilot studies, and case studies—with a total of 262 participants. The majority of these studies targeted the left DLPFC, while some explored bilateral stimulation of the DMPFC.
The core findings of the review were striking: rTMS consistently reduced binge-eating and purging behaviors, with some patients achieving complete remission. Beyond eating-related symptoms, rTMS also led to significant improvements in comorbid depression—a common issue among BN patients—and showed promising effects on reducing anxiety and food cravings (Chmiel et al., 2024). While the intervention had a positive impact on inhibitory control (a cognitive function often impaired in BN), results were mixed regarding its effects on decision-making and selective attention.
Crucially, the review confirmed the safety of rTMS for BN. No serious adverse events were reported, and the most common side effects—mild headache and scalp discomfort—were transient and resolved without intervention. Additionally, rTMS did not negatively affect blood pressure or heart rate, further supporting its tolerability (Chmiel et al., 2024). The researchers proposed several potential mechanisms underlying these effects, including the regulation of brain networks like the frontostriatal circuit, enhanced brain-derived neurotrophic factor (BDNF) levels (which promote neural plasticity), improved serotonin function, anti-inflammatory effects, and modulation of the hypothalamic-pituitary-adrenal (HPA) axis.
Despite these promising results, Chmiel et al. (2024) noted key limitations, including small sample sizes, short follow-up periods, inconsistent stimulation parameters (e.g., frequency, duration), and insufficient consideration of demographic factors like handedness and gender. These gaps highlight the need for more standardized, large-scale studies to validate the findings.
TMS for Anorexia Nervosa: A Meta-Analysis of Efficacy
Complementing Chmiel et al.’s work, a 2024 systematic review and meta-analysis by Bahadori et al. (2024) focused on TMS as a treatment for AN. Adhering to the PRISMA guidelines, the researchers searched multiple databases up to September 2024, identifying 17 relevant studies (9 of which were included in the meta-analysis) involving 129 participants. Similar to the BN research, the primary stimulation target was the DLPFC, though some studies explored the DMPFC, insula, and inferior parietal lobe (IPL).
The meta-analysis yielded compelling evidence for TMS’s efficacy in AN. Specifically, TMS significantly increased patients’ Body Mass Index (BMI)—a critical marker of physical health in AN—with a standardized mean difference (SMD) of -0.255 (P=0.045). It also led to a significant reduction in scores on the Eating Disorder Examination Questionnaire (EDE-Q), a gold-standard tool for assessing eating disorder symptoms, with an SMD of 0.634 (P=0.001) (Bahadori et al., 2024). Notably, the researchers found that longer single stimulation sessions (exceeding 20 minutes) were associated with greater improvements in EDE-Q scores, suggesting that treatment duration may be a key parameter to optimize.
Regarding stimulation targets, the DLPFC emerged as the most consistently effective site for improving AN symptoms. The DMPFC and insula also showed potential as viable targets, while stimulation of the IPL had no significant impact on body image perception—an important insight for refining treatment protocols (Bahadori et al., 2024). In terms of safety, TMS was well-tolerated, with only minor, transient side effects. A small number of studies reported serious events like worsening malnutrition or suicidal ideation, but these were not directly linked to TMS itself.
Like the BN review, Bahadori et al. (2024) identified limitations, including the lack of sham stimulation control groups in some studies, high heterogeneity in TMS protocols, small sample sizes, and limited long-term follow-up data. Additionally, the researchers noted that the impact of comorbidities (e.g., PTSD, depression) on treatment outcomes was not fully explored, a gap that future research should address.
Key Takeaways and Future Directions
Together, these two landmark studies (Chmiel et al., 2024; Bahadori et al., 2024) provide strong evidence that TMS—including rTMS—is a safe and effective supplementary treatment for both BN and AN. For patients who have not responded to traditional therapies, TMS offers a non-invasive option that targets the neural underpinnings of eating disorders, rather than just addressing symptoms.
To fully realize TMS’s potential, future research should prioritize large-scale RCTs with long-term follow-up to confirm durability of effects. Standardizing stimulation parameters (e.g., target site, frequency, duration) will be critical to establishing best practices, while incorporating demographic factors and comorbidities into study designs will help tailor treatments to individual patients. Further exploration of the underlying mechanisms will also deepen our understanding of how TMS modulates eating-related behaviors, enabling the development of more precise interventions.
Final Thoughts
Eating disorders are complex, but advancements like TMS offer hope for improved outcomes. The findings from Chmiel et al. (2024) and Bahadori et al. (2024) represent a significant step forward in validating this non-invasive approach, marking a potential paradigm shift in how we treat AN and BN. As research continues to evolve, TMS may soon become a standard part of the treatment toolkit for eating disorders, providing much-needed relief to patients and their families.
References
- Chmiel J, Stępień-Słodkowska M. Efficacy of Repetitive Transcranial Magnetic Stimulation (rTMS) in the Treatment of Bulimia Nervosa (BN): A Review and Insight into Potential Mechanisms of Action. J Clin Med. 2024;13(18):5364. Published 2024 Sep 10. doi:10.3390/jcm13185364 https://pmc.ncbi.nlm.nih.gov/articles/PMC11432543/
- Bahadori AR, Javadnia P, Bordbar S, et al. Efficacy of transcranial magnetic stimulation in anorexia nervosa: a systematic review and meta-analysis. Eat Weight Disord. 2025;30(1):4. Published 2025 Jan 15. doi:10.1007/s40519-025-01716-5 https://pmc.ncbi.nlm.nih.gov/articles/PMC11735571/