Everything you need to know about TMS and Genetics: Will Your DNA Predict Your Response? — how it works, what it costs, and how to find a provider who actually knows what they're doing.
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One of the persistent challenges in TMS is that many patients do not respond, and we cannot yet predict with precision who will. Researchers have looked at genetics as one possible predictor, but the evidence so far is limited and mixed, and no genetic test is established for guiding TMS decisions.
What You’ll Learn
- What researchers have looked at in the genetics of TMS response
- What the evidence shows about the BDNF Val66Met variant
- Whether genetic testing is useful for TMS planning today
- What else is being studied to predict response
The idea behind genetic prediction
TMS is thought to work in part by influencing brain plasticity, and plasticity is influenced by many genes. That makes it plausible that genetic variation could affect who responds. Reviews of the genetics of response to treatments such as ECT, TMS, and ketamine describe an early-stage field, with findings that are often small, inconsistent, or not yet replicated (Franklin et al., 2025).
BDNF Val66Met: promising idea, mixed evidence
Brain-derived neurotrophic factor (BDNF) is involved in plasticity, and the Val66Met variant has been associated with differences in how the brain responds to stimulation in some healthy-volunteer experiments. However, a naturalistic study of 75 patients with treatment-resistant depression who completed a standard rTMS course found no difference in symptom improvement, response, or remission between BDNF genotypes (Vigne et al.). Earlier studies reached different conclusions, so the question remains unsettled.
Other candidate genes
Other genes involved in serotonin, dopamine, glutamate, and immune function have been studied in small research samples. None is established as a reliable predictor of TMS response.
Genetic testing in practice
Commercial psychiatric pharmacogenomic panels are designed to inform medication choices, not TMS decisions. There is no genetic test recommended for deciding whether you should have TMS or how your course should be designed. If you have already had pharmacogenomic testing for medications, the results are not meant to predict TMS response.
What is being studied instead
Researchers are also exploring brain imaging (such as functional connectivity), EEG, and clinical features (for example baseline severity, illness duration, and number of prior treatment failures) as possible predictors. None of these is yet validated for routine individual prediction either.
What patients should know
- A genetic variant does not determine whether TMS will work for you. Many people respond to TMS, and many do not, for reasons we cannot yet predict.
- You do not need genetic testing before starting TMS.
- If you are concerned about response, talk with your psychiatrist about your treatment history, other options, and how progress will be measured.
Frequently asked questions
Does the BDNF Val66Met variant mean TMS will not work for me? No. Studies on this variant are mixed, and a naturalistic study of 75 patients found no difference in response by genotype.
Should I get genetic testing before starting TMS? It is not part of standard practice and is not required. Pharmacogenomic tests are designed for medication selection.
Will genetics ever help predict TMS response? It is possible, but it is a research question. Any future predictor would need validation in large studies before clinical use.
