A 40-second and a 28-minute TMS session showed no significant difference in Y-BOCS change in OCD
- In a double-blind randomized trial at a tertiary hospital in Uttar Pradesh, India, 46 drug-naive adults with OCD (Y-BOCS 16 or above) took fluoxetine 40 mg a day and received 15 daily sessions over the right DLPFC: 1 Hz rTMS (n=23, 28 minutes per session) or continuous theta burst stimulation, cTBS (n=23, 40 seconds per session).
- Total Y-BOCS fell from 26.8 to 14.9 at week 3 with rTMS and from 27.1 to 18.1 with cTBS; at week 6 it was 17.3 and 19.5. Between-group differences were not significant (week 3, p=0.074; week 6, p=0.204).
- The Y-BOCS obsessions subscale was lower with rTMS at week 3 (7.8 vs 9.8, p=0.017) and did not differ at week 6 (9.3 vs 10.9, p=0.065). HAM-A and HAM-D did not differ between groups at any time point.
- Transient headache was reported by 4 patients (17.3%) after rTMS and 9 patients (39%) after cTBS.
Two schedules, one drug
Forty-six patients took fluoxetine 40 mg a day for at least two weeks, then began 15 weekday sessions over the right dorsolateral prefrontal cortex. One arm received 1 Hz rTMS: 1,600 pulses in 28 minutes. The other received cTBS: 600 pulses in 40 seconds. Total Y-BOCS at baseline was 26.8 and 27.1. At week 3 it was 14.9 and 18.1 (p=0.074). At week 6 it was 17.3 and 19.5 (p=0.204), so both arms had drifted up from week 3.
What 28 minutes costs a clinic
Fifteen sessions of stimulation add up to seven hours in one arm and ten minutes in the other. Setup, positioning and motor threshold testing come on top, and the trial did not time them. Still, a TMS service that runs on one device in one hospital room is limited by the minutes per course, not by the price of the coil. If the 40-second protocol's Y-BOCS change holds up in larger trials, the same machine can take many more patients through a course each week. That matters most where TMS is a single unit in a general hospital, as here, rather than a suite in a large private clinic.
Where the arms differed
The obsessions subscale favoured rTMS at week 3 (7.8 vs 9.8, p=0.017), then converged by week 6. Headache was reported by 4 of 23 patients after rTMS and 9 of 23 after cTBS, more than twice as often. The authors note that patients could tell the arms apart by session length. For a practitioner, the question to ask a service is whether a short protocol is on offer, and who sees the patient after the first week.
Fifteen sessions add up to seven hours of stimulation in one arm and ten minutes in the other, with Y-BOCS falling in both.
The authors list a single centre and 46 patients, a short follow-up, only 15 sessions, no neuronavigation, and imperfect blinding because the two sessions differ in length.