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At Mid City TMS, we closely follow emerging treatments for severe and treatment-resistant Depression. One of the most notable recent developments is magnetic seizure therapy (MST), a brain stimulation treatment that appears to combine some of the antidepressant effects of electroconvulsive therapy (ECT) with a more favorable cognitive side effect profile.
A study published in The Lancet Psychiatry in 2026, “Confirmatory Efficacy and Safety Trial of Magnetic Seizure Therapy Versus Right Unilateral Ultra-Brief Electroconvulsive Therapy in Depression (CREST-MST),” is, according to its own authors, the largest randomized trial of convulsive therapy ever conducted. Led by Daniel M. Blumberger and colleagues across three academic centers, the study found that MST was statistically non-inferior to modern right unilateral ultra-brief (RUL-UB) ECT in achieving remission from Major Depressive Disorder (MDD), and caused substantially less autobiographical memory impairment. These results are genuinely encouraging, but MST is not currently cleared by the FDA for Depression and remains an investigational therapy, conducted under an FDA Investigational Device Exemption, available only in research settings.
By contrast, the treatments we offer at Mid City TMS, including transcranial magnetic stimulation (TMS) and esketamine (Spravato), are FDA-approved and supported by extensive clinical evidence available today. Here is what the CREST-MST trial actually found, and why TMS and Spravato remain the most practical, currently available advanced treatments outside of ECT.
What Is Magnetic Seizure Therapy?
MST is a form of convulsive therapy designed to induce a therapeutic seizure using high-intensity, high-frequency magnetic pulses rather than electrical current. It combines aspects of two established treatments: ECT, which induces a seizure using electrical stimulation under anesthesia, and TMS, which uses magnetic fields to stimulate the brain. Like ECT, MST requires general anesthesia, a muscle relaxant, continuous medical monitoring, specialized equipment, and recovery time after each session. Unlike standard TMS, it is not performed while the patient is awake and is not an outpatient office procedure in the usual sense. The proposed advantage is that magnetic stimulation can be focused more precisely on frontal brain regions while sparing deeper medial temporal structures involved in memory, potentially preserving antidepressant effects while reducing cognitive side effects.
Why Researchers Developed MST
ECT remains one of the most effective treatments for severe and treatment-resistant Depression, particularly for patients with suicidality or profound functional impairment. Despite this, the CREST-MST authors note that only about 1% of eligible patients accept ECT treatment, largely due to concerns about confusion, memory loss, stigma, and the need for anesthesia. MST was developed to offer a seizure-based treatment with the potential for better tolerability and fewer cognitive effects, in hopes of reaching patients who would otherwise decline convulsive therapy altogether.
Overview of the CREST-MST Trial
The trial was a multisite, randomized, double-blind, non-inferiority study conducted at three academic centers: the Centre for Addiction and Mental Health in Toronto, the University of Texas Southwestern Medical Center in Dallas, and the University of California San Diego. It was funded by the National Institutes of Mental Health.
Between 2018 and 2024, 292 adults with non-psychotic MDD were enrolled; 239 were randomly assigned to treatment, and three withdrew before receiving any sessions. Participants received either MST or RUL-UB ECT until they achieved remission, dropped out, or reached a maximum of 21 sessions. The trial’s completer sample, meaning participants who received at least eight sessions or achieved remission, included 108 ECT patients and 111 MST patients, somewhat below the study’s original target of 260 completers; enrollment was closed before that target was reached, a decision reviewed and approved by the trial’s data safety board. The two co-primary outcomes were remission of Depression on the 24-item Hamilton Rating Scale for Depression and worsening of autobiographical memory on the Autobiographical Memory Test.
Key Findings: MST Was Non-Inferior to Modern ECT on Remission
In the completer sample, the remission rate was 27.8% for RUL-UB ECT and 22.5% for MST, an absolute difference of 5.3% favoring ECT. Because this difference fell within the trial’s predefined non-inferiority margin of 15%, MST met the statistical criteria for non-inferiority (p=0.048). A similar pattern held in the broader intention-to-treat sample, where remission rates were 25.2% for ECT and 21.4% for MST. It’s worth noting that both of these remission rates are considerably lower than the roughly 50% often cited for RUL-UB ECT in earlier trials; the study’s authors attribute this partly to their stricter remission criteria, the exclusion of patients with psychotic depression, a younger average age than in prior ECT trials, and a relatively high rate of concurrent benzodiazepine use in this sample, all factors that tend to reduce remission rates in convulsive therapy research generally.
A Meaningfully Better Cognitive Safety Profile
The trial’s other co-primary outcome favored MST clearly. In the modified intention-to-treat sample, 17% of ECT patients showed clinically significant worsening on the autobiographical memory test, compared with 3% of MST patients, a highly significant difference (p=0.0003). MST patients also performed better on a broad secondary battery of cognitive measures, including global cognition, verbal learning, verbal fluency, and executive function, and recovered orientation after each session roughly three times faster than ECT patients (about 6 minutes versus 15 minutes on average).
Tolerability: A More Complicated Picture
Fewer patients discontinued MST due to non-serious side effects (3, compared with 12 in the ECT group), and MST patients reported less memory impairment, jaw pain, headache, and confusion overall. That said, the safety picture was not uniformly in MST’s favor: patients receiving MST reported notably more post-treatment breathing difficulty, likely related to how muscle relaxant dosing interacts with the seizure threshold used for MST, and the study’s authors note that numerically more serious adverse events occurred in the MST group across the full study period, though most were unrelated to the treatment itself. Remission of suicidal ideation was statistically similar between the two groups, at 48% in each. No treatment-related deaths or suicide attempts occurred in either group.
Trial Limitations Worth Knowing
A few details are worth keeping in mind when weighing how much confidence to place in these results. The completer sample fell short of the trial’s original target size, though the authors report their statistical conclusions held regardless. The study population was also overwhelmingly white (80% in the ECT group, 85% in the MST group), which limits how confidently the results generalize to more diverse patient populations. Several of the study’s investigators, including the lead author, disclosed research support, equipment support, or advisory relationships with companies that manufacture MST or TMS devices, including Brainsway and Magventure, which is standard for large device trials but worth knowing about. The published paper has also had two corrections issued by The Lancet Psychiatry since its original release, in April and July of 2026; the figures summarized here reflect the corrected published record.
Why This Study Matters, and Why MST Is Not Yet Available
The CREST-MST trial is meaningful evidence that MST may eventually offer patients who refuse ECT an effective alternative with a better cognitive safety profile. The study’s own authors are careful to frame their conclusion accordingly: they describe MST’s risk-benefit profile as supporting its consideration as a first-line convulsive therapy option, particularly for patients who decline RUL-UB ECT, rather than as a wholesale replacement for ECT. At present, MST is not FDA-cleared for Depression. It was administered in this trial under an FDA Investigational Device Exemption and a Health Canada Investigational Testing Authorization, meaning it remains a research-only treatment. Availability will depend on regulatory approval and the development of clinician training programs, steps the study’s authors note have not yet occurred.
How MST Differs from TMS
| Feature | MST | TMS |
| Requires seizure | Yes | No |
| Requires anesthesia | Yes | No |
| Cognitive side effects | Less than ECT, but possible | Minimal |
| FDA-cleared for Depression | No | Yes |
| Availability | Research centers only | Widely available |
| Treatment setting | Specialized procedural suite | Outpatient office |
TMS is a nonconvulsive, awake procedure that is FDA-cleared and does not require anesthesia or recovery time.
FDA-Cleared Alternatives Available at Mid City TMS
At Mid City TMS, we offer advanced treatments available now and supported by extensive evidence. TMS is FDA-cleared for MDD and is noninvasive, well tolerated, and effective for many patients with treatment-resistant Depression. Esketamine (Spravato) is FDA-approved for treatment-resistant Depression and can provide more rapid improvement for patients who need it. Both treatments are available in routine clinical practice and are covered by many insurance plans.
The Bottom Line on Magnetic Seizure Therapy
The CREST-MST trial found that MST achieved remission rates statistically non-inferior to modern ECT while causing meaningfully less memory impairment, a genuinely promising result for a substantial group of patients who currently decline convulsive therapy altogether. The trial also has real limitations worth weighing, including a completer sample below its original target, a study population that was not broadly representative, and a more mixed tolerability picture than “MST is simply easier to tolerate” would suggest. Most importantly for patients today, MST is not yet FDA-cleared for Depression and is not available outside of research settings.
For patients seeking proven, accessible, FDA-approved treatment now, TMS and Spravato remain among the most effective and practical options available. Learn how Mid City TMS can help and contact us today to schedule a consultation.
Sources
- Blumberger, D., McClintock, S., Thorpe, K., et al. (2026). Confirmatory efficacy and safety trial of magnetic seizure therapy versus right unilateral ultra-brief electroconvulsive therapy in depression (CREST–MST): A randomised, double-blind, non-inferiority trial in Canada and the USA. The Lancet Psychiatry