SINGAPORE – November 05, 2026 -- Two of the four patients with severe, treatment-resistant obsessive-compulsive disorder (OCD) who completed a personalised transcranial magnetic stimulation (pTMS) trial at National University Hospital (NUH) and NUS Medicine showed substantial symptom reductions, including one patient whose questionnaire score fell to zero six weeks after treatment.
OCD pilot: one patient's symptoms fell 78% in a week
The completed study is one of the first worldwide to guide intermittent theta-burst stimulation (iTBS) with "causal" brain circuits, those in which deep brain stimulation (DBS) is known to relieve OCD symptoms. Four participants enrolled between January and July 2026, and two withdrew before finishing. The other two completed 40 short iTBS sessions over five days.
One patient's Obsessive-Compulsive Inventory-Revised score fell 78% by the end of treatment week and reached zero six weeks later. The second patient improved more gradually, with a 35% reduction at four weeks. Symptoms returned about 12 weeks later, and a two-day booster treatment again produced substantial improvement.
The study was supported by a NUH Clinician Scientist Programme grant and funding from the NUS Medicine Centre for Translational Magnetic Resonance Research (TMR). Unlike DBS, pTMS requires no surgery.
Existing OCD options leave 40% to 60% of patients under-treated
The only approved OCD medicines belong to one class, serotonin reuptake inhibitors, and 40% to 60% of patients do not respond adequately. DBS is the most intensive remaining option and requires brain surgery. A non-personalised TMS form cleared in the United States since 2018 helps about 40% of these patients but stimulates the same brain region in every case.
Adj Assoc Prof Tor Phern Chern of NUH said patients with severe OCD have seen "very few genuinely new treatment options in decades."
Workflow pairs fMRI mapping with a robotic arm and nine-minute sessions
Each participant's brain circuitry is mapped with functional MRI at the NUS Medicine Centre for TMR. An algorithm developed by Assoc Prof Thomas Yeo and Dr Ru Kong then analyses the scans to set an individual stimulation target. A neuro-navigation robotic arm delivers the pulses at NUH's Centre for Interventional Psychiatry. Each iTBS session takes about nine minutes, against 37.5 minutes for conventional TMS.
Repeated fMRI scans across the study period let researchers track how brain circuits change during treatment. Routine TMS studies do not typically use this level of monitoring.
30-patient depression and anxiety trial runs to early 2029
The second study, set to begin in October 2026, aims to recruit 30 participants with depression and co-occurring anxiety. It will use two personalised stimulation targets, one linked to depression-related circuits and one to anxiety-related circuits, rather than the single region used conventionally. Participants will undergo up to 48 hours of MRI scanning over 10 months. The National Research Foundation, Singapore, funds the study, which runs until early 2029.
The investigators cite the National Council of Social Service's 2025 Quality of Life study, which found that 26% of adults experience mild depressive or anxiety symptoms, 19% moderate and 7% severe.
The team points to earlier research as context. A standard TMS study showed a 21% response rate, while a separate pTMS study reported that 70% responded within a month and 31% maintained response after 12 weeks.