Duration of TMS Sessions for OCD
A standard TMS session for OCD lasts approximately 20 minutes of active stimulation, delivered daily for 5-6 weeks (typically 29 sessions total), with each session preceded by individualized symptom provocation. 1
Standard Treatment Protocol
The FDA-approved deep TMS protocol for OCD consists of:
- 20-minute sessions of high-frequency (20 Hz) stimulation targeting the medial prefrontal cortex and anterior cingulate cortex 1
- Daily treatments, 5 days per week, for 6 weeks (29 total sessions) 2, 1
- Each session includes individualized symptom provocation immediately before stimulation 1
Timeline to Clinical Response
Most patients who respond to TMS show improvement within the first 20 sessions:
- First response typically occurs after an average of 18.5 sessions (approximately 31.6 days) 2
- Sustained one-month response is achieved after an average of 20 sessions (approximately 32.1 days) 2
- Response rates at the standard 29-session endpoint are approximately 58%, with 73% of patients achieving first response at some point during treatment 2
Extended Treatment Considerations
For patients who have not responded by 29 sessions, extending treatment beyond the standard protocol may provide additional benefit:
- Real-world data demonstrates continued reduction in OCD symptoms with sessions beyond 29 2
- Average YBOCS scores show continuous improvement with increasing numbers of sessions 2
- Response rates improve further at 1-month follow-up (45% vs 38% immediately post-treatment), suggesting delayed effects in some patients 1
Important Caveats
The 20-minute session duration refers specifically to deep TMS with the H7-coil, which is FDA-approved for OCD. 1 Other TMS protocols studied for OCD have used different durations (some studies used 40 minutes total when combining stimulation of multiple sites sequentially), but these are not FDA-approved and showed less consistent efficacy. 3
Treatment requires significant time commitment - patients must attend daily sessions for 4-6 weeks, which can be challenging for access and adherence. 4 Only highly motivated patients should be recruited for such intensive protocols given the daily treatment burden. 5
The treatment protocol differs substantially from TMS for depression, where sessions may be shorter or use different stimulation parameters. The OCD-specific protocol with symptom provocation is critical to the treatment approach. 1