| Study at a glance | |
|---|---|
| Published | Journal of Psychiatric Research, June 2026 |
| Study type | Double-blind, sham-controlled randomized clinical trial |
| Participants | 46 adults seeking to quit smoking (35 completed) |
| Treatment | 15 sessions of personalized, fMRI-guided rTMS: one of two targets, or sham |
| Main finding | Prefrontal (DLPFC) stimulation reduced cigarettes per day far more than the other two options |
What the study is about
Quitting smoking is notoriously hard, even for people who badly want to. Scientists have two main explanations for why. One is that the brain’s control system, which helps us resist urges, is too weak. The other is that its reward system, which drives cravings, is too strong. TMS can be used to push on either one. This study compared both strategies head to head.
Why they did it
Knowing which mechanism matters more would help researchers design better treatments. The team tested two approaches:
- Strengthen control: excitatory 10 Hz TMS over the left dorsolateral prefrontal cortex (DLPFC), a hub for planning and self-control.
- Quiet reward: inhibitory 1 Hz TMS over the left medial orbitofrontal cortex (OFC), a region involved in reward and craving.
What they did
Adults who were actively trying to quit smoking were randomly assigned to 15 sessions of one of three treatments: DLPFC stimulation, OFC stimulation, or sham. Each person’s target was located using their own brain scan (fMRI), making the treatment personalized. Neither participants nor researchers knew who got which treatment. The team measured cigarettes smoked per day and used fMRI before and after treatment to see how brain activity changed.
What it showed
| Group | Change in cigarettes per day |
|---|---|
| DLPFC (strengthen control) | −11.1 |
| Sham | −6.4 |
| OFC (quiet reward) | −4.9 |
- The control approach won clearly. The DLPFC group reduced their smoking significantly more than both other groups.
- Quieting reward directly didn’t help. The OFC approach did no better than sham.
- Boosting control also calmed reward. DLPFC stimulation increased activity in the prefrontal cortex and decreased activity in the orbitofrontal cortex.
- More activation, more benefit. The more the DLPFC lit up, the more participants cut back.
Why it matters
The results suggest that the best way to rein in cravings may be indirect: strengthen the brain’s control center and let it regulate the reward system from the top down. That’s a useful insight for designing future addiction treatments. There’s also a familiar connection for anyone who knows TMS. The left DLPFC is the same region targeted in standard TMS for depression, which shows how one well-understood target can support several kinds of self-regulation.
What to keep in mind
- It’s a small trial. 35 of 46 participants completed it, so larger studies are needed.
- Cutting back isn’t the same as quitting. The main outcome was cigarettes per day, not full abstinence.
- This was a research protocol. TMS is FDA-cleared to help adults quit smoking, but the cleared treatment uses a different device and protocol than this study’s personalized, fMRI-guided approach.
The bottom line
For smokers trying to quit, TMS that strengthened the brain’s self-control center reduced smoking far more than an approach aimed at dampening cravings directly. It’s a clear signal that top-down control is a key way TMS helps people cut back. At Junction Brain Health, we follow TMS research closely so our patients and referring providers know where the field is heading. Have questions about TMS? Contact our team.
Source: Li X, Caulfield KA, Carpenter MJ, Ramakrishnan V, Herrmann ES, Dancy M, George MS. DLPFC rTMS is more effective than sham or orbitofrontal stimulation for smoking cessation and alters frontal brain activity: a double-blind, sham-controlled randomized clinical trial. Journal of Psychiatric Research. 2026;197:187–195. Link to Study: https://doi.org/10.1016/j.jpsychires.2026.02.053
Link to Study: https://pmc.ncbi.nlm.nih.gov/articles/PMC13020188/