TMS therapy for depression works better than sham treatment on average, but the evidence is uneven and electroconvulsive therapy performed better in the same analysis. A 2019 review of 113 trials found that high-frequency left rTMS, the standard form of transcranial magnetic stimulation, had 3.17 times the odds of response compared with sham, [mutz-2019] and a large Canadian trial found a 3-minute version as good as the 37.5-minute standard session. [blumberger-2018] This guide covers what these studies found, the side-effects, what the research could not show and what to ask a clinic. Our overview of depression covers the condition itself.
Does TMS work for depression?
On average it does, compared with sham treatment. A 2019 network meta-analysis included 113 trials (262 treatment arms) that randomised 6,750 people, mean age 47.9 years and 59% women, with major depressive disorder or bipolar depression. In it, 10 of 18 treatment strategies were associated with higher response than sham. [mutz-2019]
Among the magnetic stimulation forms, the summary odds ratios for response against sham were 3.17 for high-frequency left rTMS (95% confidence interval 2.29 to 4.37), 3.65 for low-frequency right rTMS, 4.92 for bilateral rTMS and 3.20 for intermittent theta burst stimulation. Transcranial direct current stimulation (tDCS) was 2.65, and bitemporal electroconvulsive therapy was highest at 8.91 (2.57 to 30.91). [mutz-2019] An odds ratio of 3 means the odds of responding were about three times the odds with sham, which is not the same as three times as many people.
Summary odds ratios for response versus sham therapy from the network meta-analysis by Mutz and colleagues (2019): 113 randomised trials, 6,750 patients with major depressive disorder or bipolar depression. 95% confidence intervals: high-frequency left rTMS 2.29 to 4.37, theta burst 1.45 to 7.08, tDCS 1.55 to 4.55, bitemporal ECT 2.57 to 30.91.
When active treatments were compared with each other, bitemporal ECT and high-dose right unilateral ECT were associated with increased response, and all strategies were at least as acceptable as sham therapy. [mutz-2019]
Is a 3-minute TMS session as good as the standard one?
In the largest trial, yes. The THREE-D trial randomised 414 adults aged 18 to 65 with treatment-resistant depression, 205 to standard 10 Hz rTMS and 209 to intermittent theta burst stimulation (iTBS), at three Canadian academic centres. Scores on the 17-item Hamilton scale improved from 23.5 to 13.4 with 10 Hz rTMS and from 23.6 to 13.4 with iTBS, which met the trial’s test for non-inferiority. [blumberger-2018]
The practical difference is time. A standard session is 37.5 minutes of 10 Hz stimulation, while iTBS delivers 600 pulses in about 3 minutes, and a course still means attending daily on weekdays for 4 to 6 weeks. The authors argue that shorter sessions could let a clinic treat several times as many people each day. [blumberger-2018] Note what the trial did not test: it compared two active forms with each other, not either one with sham.
What are the side-effects of TMS?
Headache and scalp discomfort were the main ones. In THREE-D, headache was the most common treatment-related adverse event, in 131 of 204 people (64%) on 10 Hz rTMS and 136 of 208 (65%) on iTBS. Self-rated pain during treatment was slightly greater with iTBS (3.8 out of 10 versus 3.4), and dropout was low at 6% for 10 Hz and 8% for iTBS. [blumberger-2018]
The 2019 review found all of its stimulation strategies at least as acceptable as sham treatment, judged by all-cause discontinuation. [mutz-2019] That says people stayed in treatment, which is not the same as having no side-effects.
| Question | What the research found | Caveat |
|---|---|---|
| Does it beat sham? | Standard rTMS: odds ratio 3.17 for response | Quality varied; 113 trials |
| Is shorter as good? | iTBS non-inferior to 10 Hz (scores 13.4 in both) | Compared active with active, not sham |
| How long a course? | Daily on weekdays for 4 to 6 weeks | Clinics may differ |
| Is ECT stronger? | Bitemporal ECT: odds ratio 8.91 | Different treatment, different trade-offs |
| Side-effects? | Headache in about 64% to 65% | Dropouts low (6% to 8%) |
What can this research not show?
It cannot show whether TMS will work for you, or how long a benefit lasts. Five limits matter most:
- Evidence quality varied. Most trials (94 of 113, 83%) were low or unclear risk of bias, but the precision of the estimates varied considerably. [mutz-2019]
- Newer treatments are understudied. The most studied comparisons were high-frequency left rTMS and tDCS against sham, and recent treatments remain understudied. [mutz-2019]
- Short courses only. The sham-controlled comparisons concern the acute treatment of an episode, and THREE-D’s primary outcome was at 4 to 6 weeks, so durability is not covered. [blumberger-2018]
- The big trial compared two active versions. Non-inferiority of iTBS to 10 Hz shows they are similar to each other, and the authors’ evidence that rTMS works comes from earlier trials and reviews. [blumberger-2018]
- Pooled groups differ. The review combined major depressive disorder with bipolar depression, and its mean age was 47.9, so results may differ for you. [mutz-2019]
What should you ask a TMS clinic?
Ask whether you are a suitable candidate, how many sessions and which protocol they use, and what happens if it does not help. This section is our suggestion and is not something the studies tested.
Useful questions are how far you will have to travel for daily sessions over several weeks, what side-effects to expect and how they are managed, whether you should keep taking your antidepressant, and whether therapy can run alongside. Our guides to treatment-resistant depression, new antidepressants and CBT for depression cover the other options.
If you want a rough picture of your mood before an appointment, our PHQ-9 depression screener is a short self-check. It is not a diagnosis, and it does not tell you whether TMS is appropriate.
When to seek help
Speak to a doctor if low mood has lasted two weeks or more, if two antidepressants have not helped enough, or if you are thinking about TMS and want to know whether you are eligible. If you have thoughts of harming yourself or feel unable to stay safe, contact your local emergency services or a crisis helpline.
How MyFreud can help
A record shows a clinic what has and has not helped. Daily mood tracking in MyFreud shows how your days run over weeks, and the notepad is somewhere to note sleep, side-effects and how a course of treatment feels. It does not replace a doctor or a treatment clinic.
Download MyFreud and start today: App Store or Google Play.