Singapore Team Tests Personalised Brain Stimulation for Severe OCD, Eyes Depression Next
Researchers at the National University Hospital (NUH) and NUS Medicine in Singapore report encouraging early results from one of the first studies worldwide to guide transcranial magnetic stimulation (TMS) using "causal" brain circuits in severe obsessive-compulsive disorder (OCD). A second study, in patients with depression and anxiety, begins in October 2026.
- NUH and NUS Medicine completed one of the first studies worldwide using causal-circuit, fMRI-guided iTBS for severe OCD.
- Of four enrolled participants, two completed 40 sessions over five days; one saw a 78 per cent symptom drop, the other a 35 per cent reduction.
- Each iTBS session takes about nine minutes versus the conventional 37.5 minutes.
- A second study in depression with anxiety aims to recruit 30 participants and runs from October 2026 to early 2029.
A personalised alternative to uniform TMS
TMS has helped many people with major depressive disorder, according to the announcement. In standard practice, protocols are typically applied uniformly: an electromagnetic coil delivers magnetic pulses to the same predefined brain region in every patient.
NUH and the Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine) are testing a more tailored method in two studies. They combine advanced brain imaging with individualised TMS targeting, aiming to find and treat the specific brain circuits linked to each patient's symptoms. The studies are led by Adjunct Associate Professor Tor Phern Chern of NUH and Associate Professor Thomas Yeo of NUS Medicine.
The release cites earlier research as context. A clinical study on standard TMS showed a 21 per cent response rate. A separate study on personalised TMS (pTMS) reported that 70 per cent of participants responded within the month after treatment, and 31 per cent still showed a response after 12 weeks.
The workflow is the same across both studies. Functional MRI (fMRI) first maps each participant's brain circuitry at the NUS Medicine Centre for Translational Magnetic Resonance Research. An algorithm first developed by Yeo and Dr Ru Kong analyses the scans. The results guide a neuro-navigation robotic arm that delivers intermittent theta-burst stimulation (iTBS). Each iTBS session takes about nine minutes, compared with the conventional 37.5 minutes. Treatment takes place at the Centre for Interventional Psychiatry at NUH.
Participants also receive frequent, repeated fMRI scans, which the researchers say is not typical in routine TMS studies. This lets them track how brain circuits change during treatment and how that relates to symptom improvement.
Early OCD results from four participants
OCD is among the hardest mental health conditions to treat, according to the release. The only approved medicines belong to one class, serotonin reuptake inhibitors, and 40 to 60 per cent of patients do not respond adequately. For those who fail medication and psychotherapy, the most intensive option left is deep brain stimulation (DBS), which requires brain surgery. A non-personalised form of TMS, cleared for OCD in the United States since 2018, helps about 40 per cent of these patients but stimulates the same region in every case.
The completed study used causal circuits, in which DBS has been shown to relieve OCD symptoms, to identify a general treatment region. That region was then refined to each participant's own default mode network using fMRI and the NUS Medicine-developed algorithm. Unlike DBS, pTMS is non-invasive and needs no surgery.
Four people with severe, treatment-resistant OCD enrolled between January and July 2026. Two withdrew before completing treatment. The other two completed 40 short iTBS sessions over five days, and both had a substantial reduction in symptoms on the Obsessive-Compulsive Inventory-Revised (OCI-R).
- One patient's symptom scores fell by 78 per cent by the end of the treatment week and reached zero six weeks later.
- The other improved more gradually, with a 35 per cent reduction four weeks after treatment. Symptoms returned about 12 weeks later, and after a two-day booster treatment the patient again improved substantially.
Tor said: "For people with severe OCD who have tried medication and therapy without success, there have been very few genuinely new treatment options in decades." The sample is very small, and the team says the findings support further evaluation, not a conclusion on effectiveness.
A larger study in depression and anxiety
The second study examines how brain networks and symptoms change during pTMS in people with depression who also have anxiety. The release points to the National Council of Social Service's 2025 Quality of Life study, which reported that 26 per cent of adults experience mild depressive or anxiety symptoms, 19 per cent moderate symptoms and 7 per cent severe symptoms.
The study aims to recruit 30 participants and will run from October this year until early 2029. Rather than targeting the single region commonly used for depression, it will use two types of personalised targets, linked to depression-related and anxiety-related circuits. Participants will have up to 48 hours of MRI scans over 10 months. The National Research Foundation, Singapore funds the study. The OCD work was supported by a NUH Clinician Scientist Programme grant and funding from the Centre for TMR at NUS Medicine.
What it means
If confirmed in larger studies, the OCD approach could offer new hope to Singaporeans who have not responded well to conventional treatments, according to the release. The depression and anxiety trial is intended to support more precise, individualised brain target maps for future pTMS treatments.
Yeo said the studies are "an important step towards a more precise and individualised approach to mental health care." For now, the evidence in OCD rests on two completed cases, so larger trials will determine whether the results hold.
