TMS progress monitoring: what to measure, when, and what the numbers mean
A TMS course is typically 30 to 36 acute sessions over four to six weeks, followed by a taper. Progress monitoring exists to answer three questions during that window: is this patient responding, should the protocol change, and after the course ends, is depression coming back. All three are answered with the same repeated instrument, so the difficulty is cadence and interpretation rather than instrument choice.
A cadence that fits the course
| Phase | When | What you are looking for |
|---|---|---|
| Baseline | Before session 1 | The score every later change is measured against |
| Acute course | Every 5 sessions (roughly weekly) | Early movement; flat scores by session 10-15 prompt a protocol review |
| Mid-course review | Around session 20 | Response (a 50% or greater drop from baseline) or not |
| End of acute course | Session 30-36 | Response and remission status at completion |
| Taper | Weekly during taper | Stability as session frequency drops |
| Maintenance | Monthly for 12 months | Early relapse signal and retreatment timing |
Response, remission and non-response
Response is conventionally a 50% or greater reduction from the baseline total. Remission on the PHQ-9 is usually taken as a total below 5. Non-response by the end of an adequate acute course is a clinical decision point, not a failure of measurement — it is the trigger for reviewing coil placement, stimulation parameters, adherence to the session schedule, and concurrent treatment.
Put plainly, a baseline of 20 dropping to 9 is a response but not a remission; dropping to 4 is a remission; sitting at 17 by session 20 is the conversation you want to have before session 30 rather than after.
Relapse detection after the course ends
Relapse risk is highest in the months after the acute course, and it is the period with the least contact. Monthly monitoring for a year catches worsening while a short retreatment course is still the likely answer. Two signals matter: a rise of five points or more on the PHQ-9 between sends, and any return above the moderate threshold after remission.
Both raise an alert to the treating clinician rather than waiting for the patient to call, which is also what makes the maintenance year clinically and commercially worthwhile for a TMS practice.
- A five-point rise between consecutive PHQ-9 administrations is a tier-one deterioration signal.
- Any endorsement of the safety item escalates immediately and shows the patient the 988 Lifeline.
- A documented baseline, end-of-course and maintenance score is also the evidence a payer asks for when authorizing retreatment.
Documentation payers actually ask for
Authorization and reauthorization requests generally turn on the same three items: a documented pre-treatment severity score, documented failed medication trials, and documented change during treatment. Repeated, timestamped scores cover the first and third without a chart reconstruction.
Because each send and completion is logged, an end-of-course summary can be produced as a branded PDF with PHI switched off where required.
The workflow end to end
Baseline before session 1
Emailed PHQ-9 with a single-use link; the score anchors every later comparison.
Weekly through the acute course
Automatic sends roughly every five sessions, with one reminder.
Review at session 20
Response or non-response drives a protocol conversation before the course ends.
Weekly through taper
Confirms stability as frequency drops.
Monthly for 12 months
Catches relapse early, when a short retreatment course is still the likely answer.
Related tools and guides
Frequently asked questions
How often should PHQ-9 be administered during a TMS course?
A baseline before the first session, then roughly every five sessions (about weekly) through the acute course, weekly during taper, and monthly for a year afterwards to catch relapse early.
What counts as a response to TMS?
Conventionally a reduction of 50% or more from the baseline severity score. Remission on the PHQ-9 is usually taken as a total below 5.
When should a non-responding patient prompt a protocol change?
If scores are flat by session 10 to 15, and certainly if there is no response by around session 20, that is the point to review coil placement, stimulation parameters, session adherence and concurrent treatment — before the acute course runs out.
How is relapse detected after treatment ends?
Monthly monitoring, with an alert on a rise of five points or more between administrations or a return above the moderate threshold after remission. That usually reaches the clinician well before the patient calls.
Does this help with payer documentation for retreatment?
Yes. Timestamped baseline, end-of-course and maintenance scores document pre-treatment severity and change during treatment, which is most of what a reauthorization request asks for.
References
- O'Reardon JP, et al. Efficacy and safety of transcranial magnetic stimulation in the acute treatment of major depression. Biol Psychiatry, 2007.
- Carpenter LL, et al. Transcranial magnetic stimulation for major depression: a multisite, naturalistic, observational study. Depress Anxiety, 2012.
- Dunner DL, et al. A multisite, naturalistic, observational study of TMS for patients with pharmacoresistant MDD: durability of benefit over a 1-year follow-up. J Clin Psychiatry, 2014.
Educational information for clinicians. Screening results are not a diagnosis and do not replace clinical assessment. If you or someone you know is in crisis, call or text 988 for the Suicide & Crisis Lifeline.