TMS for Treatment-Resistant Depression: What to Expect

You did what you were asked to do. You took the first antidepressant for weeks, then a second, maybe a third, and you’re still waiting to feel like yourself. When someone finally mentions TMS, it can sound like the last stop on a long road. For many people, it’s closer to the next reasonable step.

Your brain runs on electrical signals passed between nerve cells, and transcranial magnetic stimulation, or TMS, works directly on that signaling. As described in an FDA clearance summary, a TMS system delivers repetitive magnetic pulses to the left dorsolateral prefrontal cortex, an area toward the front of the brain, without surgery. That level of precision means treatment reaches one targeted region instead of circulating through your whole body.

For most people, the standard path after an antidepressant doesn’t work is another medication: a higher dose, a switch, or an add-on. That approach has strong evidence behind it. In the STAR*D study of more than 3,600 outpatients, remission rates were 36.8% with the first treatment step and 30.6% with the second. The results are real, and the science is well established.

But the odds shrink with each new medication step, and at Siggy we’d rather you hear about every evidence-based option than default to another prescription.

TMS is one of those options. It’s a noninvasive treatment cleared by the FDA for adults whose depression hasn’t improved enough on antidepressant medication, and it treats the same illness through a physical stimulus to one brain region rather than a drug. Its results tend to be strongest when it comes earlier, before many more failed trials pile up. That pattern comes from trial data rather than marketing, and it should shape the timing of treatment.

What This Page Covers

• What Makes Depression Treatment-Resistant?
• Where Does TMS Fit After Antidepressants Haven’t Worked?
• What Are Realistic Results for TMS in Treatment-Resistant Depression?
• What Predicts Whether TMS Will Work for You?
• What Happens Week by Week During a TMS Course?
• Should You Stay on Your Antidepressant During TMS?
• What Happens After a TMS Course Ends?
• How Siggy Fits In
• The Bottom Line on TMS for Treatment-Resistant Depression
• Start Your Anonymous Intake

What Makes Depression Treatment-Resistant?

There’s no single universal definition. The one used most often, and adopted by regulators according to a 2023 World Psychiatry review, is an inadequate response to at least two antidepressants despite an adequate dose, an adequate length of treatment, and taking the medication as prescribed. The review estimates that at least 30% of people with depression meet that definition.

It also flags a problem worth knowing about. A significant share of people labeled treatment-resistant are pseudo-resistant, meaning a past trial was too short, too low a dose, or too hard to stick with. Sorting that out is the first step, because it changes what comes next. Our guide to treatment-resistant depression walks through how to tell whether your past trials really counted.

Where Does TMS Fit After Antidepressants Haven’t Worked?

The STAR*D data show why people start looking beyond medication. Remission rates fell to 13.7% and 13.0% at the third and fourth treatment steps, and people who needed more steps relapsed more often during follow-up.

TMS has a lower entry point than many people assume. The FDA clearance summary indicates TMS for adults with major depressive disorder who haven’t achieved satisfactory improvement from prior antidepressant medication in the current episode, which is a lower bar than two failed trials. Coverage rules can be stricter, and our guide to TMS insurance coverage explains what plans typically ask for.

The World Psychiatry review describes TMS as established and effective for treatment-resistant depression. It sits alongside other options, including esketamine, add-on medications, and electroconvulsive therapy (ECT), which the review notes may be more effective than conventional TMS. Our comparison of treatment-resistant depression options covers those trade-offs.

What Are Realistic Results for TMS in Treatment-Resistant Depression?

TMS helps a meaningful share of people whose depression hasn’t responded to medication, though it doesn’t help everyone. “Response” usually means symptoms dropped by about half, and “remission” means symptoms are low enough to count as minimal.

The clearest real-world picture comes from a 42-practice study of 307 outpatients who had tried an average of 2.5 adequate antidepressant treatments in their current episode. Clinicians rated 58.0% as responders and 37.1% as in remission. Patients’ own questionnaires were a little more conservative, with response rates of 41.5% to 56.4% and remission rates of 26.5% to 28.7%.

Shorter sessions can work as well as longer ones. The THREE-D trial randomized 414 adults with treatment-resistant depression to standard 37.5-minute sessions or 3-minute theta burst sessions, and the shorter protocol was no less effective. Accelerated schedules are newer. In a double-blind accelerated TMS trial of 29 people treated over 5 days, the FDA summary reports remission in 78.6% with active treatment compared with 13.3% with sham. That summary also notes the supporting studies came from a single site and that effectiveness wasn’t established beyond 4 weeks.

The table below summarizes the three studies above.

Study	Who Was Treated	What Happened
Real-world practice study	307 outpatients, average 2.5 failed treatments	58% response, 37.1% remission (clinician-rated)
THREE-D trial	414 adults with treatment-resistant depression	3-minute sessions matched 37.5-minute sessions
Accelerated 5-day trial	29 adults, active vs sham	78.6% remission vs 13.3% with sham

What Predicts Whether TMS Will Work for You?

Your treatment history matters most. In a 301-patient multisite trial, the number of prior treatment failures in the current episode was the strongest predictor of TMS response. A shorter current episode was also linked with better results, and in the trial’s open-label phase, people without a co-occurring anxiety disorder did better.

The difference can be large. In a THREE-D secondary analysis, remission was 17.3% among people with three or more failed medication trials, compared with 29.4% among people with fewer. Not every study has found the same link, but the World Psychiatry review concluded that more prior antidepressant failures are associated with weaker TMS results.

Rather than ruling you out, these factors are reasons to ask about TMS sooner, and to give your care team an accurate account of every medication you’ve tried.

What Happens Week by Week During a TMS Course?

A standard course runs 5 days a week for 4 to 6 weeks, usually 20 to 30 sessions. At the start, your team measures your motor threshold, the lowest pulse strength that makes your hand twitch, which the FDA summary describes as the basis for setting your individual dose. Our guide to what TMS therapy is covers what a session feels like and who should avoid it.

Improvement doesn’t look the same for everyone. A trajectory analysis of 388 THREE-D participants found four patterns:

• About 19% improved rapidly.
• About 30% started with more severe symptoms and improved steadily.
• About 40% started with milder symptoms and improved steadily.
• About 11% didn’t respond.

Differences between those groups were detectable by the first week. Higher starting symptom scores were linked with nonresponse, while older age, lower self-rated symptoms, and not taking a benzodiazepine were linked with rapid response.

Side effects are usually manageable. Headache was the most common one in THREE-D, affecting about 65% of people in each group. Treatment pain averaged 3.8 out of 10 for the 3-minute sessions and 3.4 for the longer ones. Seizures are rare. A TMS seizure survey covering more than half a million sessions found 18 seizures, about 0.31 per 10,000 sessions.

Should You Stay on Your Antidepressant During TMS?

For most people, the plan is to stay on it. THREE-D enrolled people who had been on stable antidepressant doses for at least 4 weeks, so its results describe TMS added to ongoing medication.

Benzodiazepines may be the exception. In a published research letter reviewing two datasets of 388 and 181 participants, researchers noted that benzodiazepines stood out in both as the medication most consistently linked with poorer TMS response. They suggested clinicians consider reducing benzodiazepines during TMS and called for prospective research to confirm the link. Never stop or cut back any medication on your own. Talk with your prescriber first, so any change is planned and monitored.

What Happens After a TMS Course Ends?

Benefits often last, especially with continued care. In a one-year follow-up study of 257 people who completed a TMS course, 120 met response or remission criteria at the end of treatment. Of those, 75 (62.5%) still met response criteria throughout the following year while continuing antidepressant medication. About 36.2% of the full group had TMS reintroduced at some point, for an average of about 16 treatment days.

That’s why checking in matters after the last session. Noticing early changes in sleep, energy, or interest gives you and your clinician time to act before a full relapse.

How Siggy Fits In

Siggy doesn’t provide TMS. Siggy’s licensed prescribers diagnose and treat the full range of mental health conditions, including depression. What Siggy can do is help you put your treatment history into one clear record: which medications you’ve taken, at what dose, for how long, and what happened. That’s the information a TMS team, or any clinician, needs to judge whether your past trials were adequate.

The anonymous intake asks for no name, email, or account, and you’ll get a downloadable summary to keep or share with any clinician, so you don’t have to retell your story from scratch. If medication for anxiety or depression is part of your plan, a licensed prescriber reviews your full intake before anything is prescribed.

Siggy isn’t an emergency service. If you’re having thoughts of suicide, call or text 988. In an emergency, call 911. This article is for education only and isn’t a substitute for personal medical advice. It reflects sources available as of October 2026.

The Bottom Line on TMS for Treatment-Resistant Depression

TMS is an evidence-based next step for depression that hasn’t lifted with medication, with real-world remission rates of roughly 27% to 37% depending on who’s rating, and lasting benefit for many who respond. It works best earlier in the treatment sequence, it’s usually added to the medication you already take, and it can be repeated if symptoms return. If you’re still deciding, our look at whether TMS works compares it with switching medications.

Start Your Anonymous Intake

If you’re in crisis right now, call 911 or call or text 988 first. If you’ve tried antidepressant after antidepressant and no one has helped you see the whole picture, start your anonymous intake. It’s free, there’s no name or email required, and a licensed prescriber reviews your intake before anything is prescribed. Your summary is yours to share with any TMS team or clinician.