How long is one TMS session?

NIMH says a typical session lasts from 3 to 40 minutes. In the THREE-D trial, a theta burst session took 3 minutes and a standard 10 Hz session took 37.5 minutes. Your clinic can tell you which protocol it uses.

Is theta burst TMS as effective as standard TMS?

In the THREE-D trial of 414 adults, it was not worse. Average depression scores fell from about 23.5 to 13.4 in both groups after 4 to 6 weeks. People rated the pain of theta burst slightly higher, at 3.8 out of 10 compared with 3.4.

What are the common side effects of TMS?

NIMH lists discomfort at the treatment site, tingling or contraction of scalp, jaw, or face muscles, mild headaches, brief lightheadedness, and dizziness. It says most side effects appear to be mild and short-term. In the THREE-D trial, about 65% of participants reported headache.

Can teenagers have TMS for depression?

NIMH says that in March 2024 the FDA cleared rTMS as an add-on treatment for depression in adolescents 15 years and older. It is not approved for youth under 15. A child and adolescent psychiatrist can advise on the options.

Does TMS work better if my depression is less severe?

The THREE-D analysis gives some evidence for that. Higher starting symptom scores were linked to the no-response pattern. Older age, lower self-rated symptom scores, and no benzodiazepine use were linked to the rapid-response pattern.

How Long Does TMS Take to Work for Depression?

The short answer: A standard course of TMS runs 5 days a week for 4 to 6 weeks, which is 20 to 30 sessions. In one large trial, about 1 in 5 people improved fast, and most improved steadily across the whole course. Trials judge the result at week 4 to week 6, so the full course is the fair test. An accelerated protocol packs the treatment into 5 days.

How long is a standard course of TMS?

Repetitive transcranial magnetic stimulation (rTMS, often called TMS) uses magnetic pulses on a mood-related area at the front of the brain. The National Institute of Mental Health (NIMH) gives the usual schedule: daily sessions, 5 days per week, for 4 to 6 weeks. One session lasts from 3 to 40 minutes.

The Clinical TMS Society consensus review describes the same course as 20 to 30 sessions. The two trials behind the first devices used that schedule:

A 2007 trial of 301 patients gave sessions five times a week for 4 to 6 weeks. It measured its main result at week 4.
A 2010 trial of 199 patients gave 3 weeks of weekday sessions. People who improved continued for up to 3 more weeks. Each session lasted 37.5 minutes.

NIMH says the FDA cleared the first rTMS device in 2008. The clearance covered people whose depression did not respond to at least one antidepressant in the current episode. Our guide to treatment-resistant depression explains where TMS sits among the other options.

When do people usually notice a change?

It differs from person to person. The best data come from a 2019 analysis of 388 people in the THREE-D trial. All had depression that had not responded to one to three antidepressants. The researchers found four patterns:

Rapid response: 19% of participants.
Steady response, higher starting symptoms: 30%.
Steady response, lower starting symptoms: 40%.
No response: 11%.

So 7 in 10 people improved in a straight line across the 4 to 6 weeks. The groups already differed by week 1, but most people did not feel a sudden change. The gain built up session by session.

This is why clinics ask you to finish the course before you judge it. The same patience applies to medication, as our article on how long antidepressants take to work explains.

How many people respond or reach remission?

The answer depends on the type of study. "Response" means a large fall in symptom scores. "Remission" means that few or no symptoms remain.

Blinded trials give the lowest numbers. In the 2010 trial, 14.1% of people on active TMS reached remission, compared with 5.1% on sham treatment. The patients took no antidepressants during that trial. In its open-label follow-up phase, almost 30% reached remission.

Studies in routine practice give higher numbers:

A 2012 study of 307 patients at 42 US clinics found a clinician-rated response rate of 58.0% and a remission rate of 37.1%. Patient-rated response ran from 41.5% to 56.4%. Patient-rated remission ran from 26.5% to 28.7%.
A 2020 registry report on 5,010 patients at 103 sites found response rates of 58% to 83% and remission rates of 28% to 62%. The range depends on the rating scale and on whether the count includes only people who completed the course.

Read the registry numbers with care. The authors note that the treatment was open label and that sites joined the registry voluntarily. These studies have no sham group for comparison.

Do theta burst and accelerated protocols work faster?

Theta burst makes each session shorter. It does not make the course shorter. The THREE-D trial compared intermittent theta burst stimulation (iTBS) with standard TMS in 414 adults. An iTBS session took 3 minutes. A standard session took 37.5 minutes. Both groups had sessions 5 days a week for 4 to 6 weeks.

The results were almost the same. Average scores on a 17-item depression scale fell from 23.5 to 13.4 with standard TMS and from 23.6 to 13.4 with iTBS. Headache was the most common side effect in both groups.

Accelerated protocols do shorten the course. The best-known one is Stanford neuromodulation therapy (SNT, also called SAINT). It delivers 50 iTBS sessions as 10 sessions a day for 5 days, with 50 minutes between sessions. An MRI scan sets the target for each person.

In the first open-label study, 19 of 21 participants met remission criteria after the 5 days.
In the double-blind SNT trial, 29 participants received active or sham treatment. Four weeks later, depression scores had fallen 52.5% in the active group and 11.1% in the sham group.

The FDA record shows that it cleared the Magnus Neuromodulation System with SAINT Technology on September 1, 2022. NIMH says accelerated protocols often work within a week. The evidence is still small: the blinded trial had 29 people, and its authors said more trials must test how long the benefit lasts.

How long does the benefit last, and will I need more sessions?

For about half of the people who respond, the benefit lasts a year. A 2019 meta-analysis of 19 studies followed people who had responded to a first course. The share who still met response criteria was:

66.5% at 3 months
52.9% at 6 months
46.3% at 12 months

A one-year follow-up of 257 patients in routine practice found a similar result. Of 120 people who had responded or remitted, 62.5% still met response criteria through the year. They continued their antidepressant medication and could return for more TMS.

Many people need repeat sessions. In the one-year follow-up study, 36.2% of patients had TMS reintroduced because symptoms returned. Those patients had an average of 16.2 more treatment days.

The 2019 meta-analysis found that people who received maintenance treatment had higher response rates at some follow-up points. Its authors said maintenance should be considered in practice. No single schedule is standard. NIMH says research is still underway on the best follow-up approach to sustain improvement.

TMS is usually one part of a plan that also includes medication, talk therapy, or both. See depression treatment options compared for the other parts.

What happens if TMS does not work?

The first option is often more sessions. An extension study followed 73 people who had not responded to active TMS in the 2007 trial. After up to 6 more weeks of treatment, 26.0% responded and 11.0% reached remission. The authors concluded that longer courses may help some people who do not respond in 4 weeks.

A smaller analysis of 33 non-responders to deep TMS gave a similar signal. Deep TMS uses a different coil. With twice-weekly sessions, 60.6% responded within four more weeks. Only 39.4% held that response for the rest of the study.

If more sessions do not help, your psychiatrist can review the diagnosis and the other treatments for hard-to-treat depression. Symptoms that overlap with another condition can change the plan. For example, NIMH notes that the FDA also cleared rTMS for severe OCD in 2018, a condition that ocd.md covers.

If you have thoughts of suicide at any point, call or text 988 (the 988 Suicide and Crisis Lifeline). Do not wait for the course to end.

The bottom line

Plan for 4 to 6 weeks of weekday sessions, and expect a gradual change. About 1 in 5 people improve fast, and about 1 in 10 do not respond. In routine practice, about half of patients or more respond, and about a third reach remission. Among responders, about half keep the benefit for a year, and repeat sessions are common. A 5-day accelerated protocol is FDA-cleared, but its evidence base is still small.

Last updated: October 2026. This article is for informational purposes only and does not constitute medical advice. A psychiatrist who knows your history must decide if TMS is suitable for you and which protocol to use. If you are in crisis, call or text 988.