This glossary explains 60 terms you are likely to meet when reading about or starting TMS (transcranial magnetic stimulation), from motor threshold to prior authorization. Each entry is short, in plain language, and links to the page that covers the topic in depth. Where a definition involves a number or a study, the source is listed at the end of the page.
Some terms describe uses that are not FDA-cleared, such as single-day protocols or TMS for anxiety disorders alone; those entries say so. If you are new to TMS, start with what TMS therapy is, then come back here when a word trips you up. The full TMS guide lists every topic.
Terms people often mix up
| Pair | The difference |
|---|---|
| Cleared vs approved | TMS devices are cleared (510(k)) or De Novo-granted; drugs like Spravato are approved |
| Response vs remission | Response is a big improvement; remission means symptoms are low enough to count as well |
| rTMS vs deep TMS | Deep TMS is a kind of rTMS that uses an H-coil instead of a figure-8 coil |
| iTBS vs accelerated TMS | iTBS is a pulse pattern; accelerated describes several sessions per day. SAINT uses both |
| Maintenance vs retreatment | Maintenance is scheduled to prevent relapse; retreatment is a new course after relapse |
| Open-label vs sham-controlled | Sham-controlled trials compare against a fake treatment and give more reliable effect sizes |
A to C
Accelerated TMS
A schedule that packs several sessions into each treatment day to shorten a course. SAINT was the first accelerated protocol cleared, in 2022; BrainsWay (2025) and MagVenture (2026) accelerated protocols have since been cleared too. Coverage is a separate question, covered in is accelerated TMS covered by insurance.
Acute course
The first, intensive block of treatment. Expert consensus tells patients that a standard acute course of 20 to 30 sessions over about six weeks will very likely be needed to match the results of the regulatory trials. A typical TMS course, week by week shows how it unfolds.
Adjunct
Added to existing treatment rather than replacing it. TMS clearances for OCD and for adolescent depression are worded "as an adjunct," meaning alongside other treatment such as medication. See TMS for teens and young adults.
Anxious depression
Major depression with prominent anxiety symptoms. Several systems are cleared "for decreasing anxiety symptoms" in adults with major depression; none is cleared for anxiety disorders alone. Details in TMS for anxiety.
Beam F3 method
A quick way to locate the treatment spot from three head measurements instead of a full EEG-cap measurement. A 2023 randomized trial found it about as effective as a ruler-based method in people with head circumference up to 60 cm. More in how TMS targets are found.
Bilateral TMS
Stimulation of both sides of the prefrontal cortex in one session, for example high-frequency on the left and low-frequency on the right. Canada's CANMAT guideline rates sequential bilateral rTMS a second-line protocol.
Booster session
Informal name for extra sessions given when symptoms start to return after a course. Practices differ on how and when to use them, and insurers often treat them as maintenance. See TMS maintenance and booster sessions.
CANMAT
The Canadian Network for Mood and Anxiety Treatments, which publishes widely cited depression guidelines. Its 2023 update rates rTMS a first-line treatment for treatment-resistant depression, with Level 1 evidence for acute efficacy.
Coil
The hand-held or helmet-shaped part that rests on your head and produces the magnetic pulses. The two main families are figure-8 coils and H-coils; deep TMS vs standard TMS compares them.
Contraindication
A reason a treatment should not be used. For TMS, the main contraindications are conductive or magnetic metal implanted in the head or within 30 cm of the coil, and implants such as cochlear implants or brain stimulators. See TMS with fillings, implants or tattoos.
CPT codes 90867, 90868, 90869
Billing codes for TMS: 90867 for the initial session with mapping and motor threshold, 90868 for each later session, and 90869 when motor threshold is re-measured. They show up on claims and in prior authorization requests.
D to F
Deep TMS
TMS delivered with an H-coil, which is designed to stimulate a broader and somewhat deeper area than a figure-8 coil. BrainsWay Deep TMS was cleared for depression in 2013. See deep vs standard TMS.
De Novo
An FDA pathway for new kinds of lower-risk devices that have no existing equivalent. The result is "De Novo granted," not "approved." NeuroStar, the first TMS system for depression, reached the market this way in October 2008. See what FDA clearance means.
DLPFC
Dorsolateral prefrontal cortex, a region near the front and side of the brain involved in mood regulation and planning. Standard depression TMS targets the left DLPFC. How TMS works explains why.
Durability
How long improvement lasts after a course. In a 2019 pooled analysis, 46.3% of people who responded were still responding at 12 months. A fair range from the studies is roughly half to about 6 in 10 initial responders doing well at one year. See how long TMS results last.
ECT
Electroconvulsive therapy, which induces a brief controlled seizure under general anesthesia. An acute course usually takes 6 to 12 sessions. It is more effective than TMS overall, especially for psychotic depression; TMS vs ECT compares the two.
Esketamine (Spravato)
A nasal-spray form of ketamine, FDA-approved for treatment-resistant depression in March 2019. It is given in certified settings with at least 2 hours of monitoring after each dose. Compared in TMS vs ketamine therapy.
FDA-cleared vs FDA-approved
Many medical devices are "cleared" through a 510(k) submission showing they are substantially equivalent to a device already on the market; "approval" is reserved for the highest-risk devices and for drugs. Every TMS device is cleared or De Novo-granted, not approved.
Figure-8 coil
The standard flat coil shaped like the number eight, which focuses the field on a small spot under its center. The original pivotal depression trials used it.
fMRI-guided targeting
Choosing the treatment spot from a brain scan that maps how regions work together, usually the area most out of sync with the subgenual cingulate. The first large trial of this approach did not beat standard targeting. See TMS targeting.
H to L
HAM-D (HDRS)
The Hamilton Depression Rating Scale, a clinician-rated interview used in many TMS trials. Several versions of different lengths exist, so scores are not directly comparable between versions. Tracking progress during TMS explains rating scales.
H-coil
The helmet-shaped coil used in deep TMS. The H1 version targets the prefrontal cortex for depression; the H7 version targets the medial prefrontal and anterior cingulate cortex for OCD. See TMS for OCD.
Hearing protection
Earplugs or earmuffs worn during every session because each pulse makes a loud click. FDA guidance calls for protection rated at 30 dB of noise reduction. What TMS feels like describes the sound.
High-frequency rTMS
Stimulation at 5 pulses per second or faster, used to increase activity in the left DLPFC. Standard protocols use 10 Hz; deep TMS for depression has used 18 Hz.
Inter-train interval
The pause between bursts of pulses. Shortening it shortens the session: on the current NeuroStar label, a standard session can take as little as 18.75 minutes instead of 37.5. See the first TMS session.
iTBS (intermittent theta burst)
A patterned protocol that delivers bursts of three rapid pulses and takes about 3 minutes per session. In the 2018 THREE-D trial it was non-inferior to 10 Hz rTMS. See theta burst stimulation explained.
Ketamine
An anesthetic used off-label for depression, usually as an IV infusion. FDA says ketamine "is not FDA approved for the treatment of any psychiatric disorder." The practice's ketamine therapy page covers it in depth.
Low-frequency rTMS
Stimulation at 1 pulse per second or slower, usually to the right DLPFC, which tends to calm activity. CANMAT rates it first-line with Level 2 evidence.
M to N
MADRS
The Montgomery-Åsberg Depression Rating Scale, a clinician-rated scale often used in depression trials. The SAINT open-label study defined remission as a MADRS score below 11. Scales differ, so always check which one a result used.
Maintenance TMS
Scheduled sessions after a successful course to try to prevent relapse. A 2025 consensus calls it promising but says the right frequency is unclear, and it is not covered by most insurers. Medicare does not cover it. See maintenance sessions.
Major depressive disorder (MDD)
The formal diagnosis behind most TMS treatment: a period of low mood or loss of interest with other symptoms, lasting weeks and affecting daily life. What is TMS therapy explains how TMS is used for it.
Mania switch
A shift into hypomania or mania during treatment. A 2021 meta-analysis of blinded trials found the risk no different from sham. People with bipolar disorder still need careful monitoring; see TMS side effects.
MeRT
An EEG-guided TMS approach whose system was cleared in June 2026 as an add-on treatment for adults with PTSD, the first TMS-based clearance for PTSD. See TMS for anxiety for how PTSD fits among related conditions.
Motor threshold (MT)
The lowest strength that makes your hand or fingers twitch when the coil is over the motor cortex. Treatment strength is set as a percentage of it, for example 120% in standard protocols. See motor threshold and dosing.
Neuronavigation
A camera-and-software system that uses your MRI to guide the coil to a chosen brain spot. An early trial found better results at 4 weeks than with a ruler method, though the authors said larger studies were needed.
O to P
Off-label
Using a device or drug for a condition, age or protocol outside its cleared or approved labeling. It can be legitimate, but evidence is usually thinner and insurance rarely pays. TMS myths and facts covers common confusions.
ONE-D
A single-day protocol combining 20 iTBS sessions with two off-label medicines given beforehand. The Clinical TMS Society says it is not FDA-cleared and the evidence does not support recommending it over established approaches. See one-day accelerated TMS.
Open-label study
A study in which everyone knows they are getting active treatment, with no sham group. Large registry studies are open-label, and their high response figures should not be compared with sham-controlled trial results. Response vs remission explains why.
PHQ-9
A short self-report depression questionnaire with nine questions. Many clinics use it to track progress; a post-treatment score under 5 was used as remission in the adolescent registry analysis. See tracking your progress.
Prior authorization
Approval your insurer must give before treatment starts for it to pay. For TMS it usually requires documentation of diagnosis, prior medication trials and often therapy. TMS prior authorization, step by step.
Pulse
A single brief magnetic burst from the coil. A standard 10 Hz session delivers 3,000 pulses. SAINT delivers 90,000 pulses over its five days.
R to S
Relapse
Return of depression after improvement. Planning for it, rather than hoping it will not happen, is part of good care. See life after TMS: relapse prevention.
Remission
Symptoms low enough to count as essentially well, defined by a cutoff on a scale, such as an HDRS-21 score under 10 in the deep TMS pivotal trial. Remission is a higher bar than response.
Response
A meaningful improvement, usually defined as at least a 50% drop in a depression score. For OCD trials the bar is usually a 30% drop on the Y-BOCS. Response vs remission goes deeper.
Retreatment
A second course after depression returns. In a 2026 multisite cohort, 82.5% of people who had responded to a first course responded again. That study was retrospective. See what if TMS does not work for the other side.
rTMS
Repetitive transcranial magnetic stimulation: trains of pulses delivered repeatedly, as opposed to the single pulses used in research. When people say TMS for depression, they nearly always mean rTMS. Start with what TMS therapy is.
SAINT (SNT)
Stanford Accelerated Intelligent Neuromodulation Therapy, also called Stanford Neuromodulation Therapy (SNT): 10 iTBS sessions a day for 5 days at an MRI-chosen target. FDA cleared it in September 2022 through a 510(k). See SAINT: what it is and is not.
Seizure
The most serious acute risk of TMS, and rare. Within published guidelines and without risk factors, a survey found fewer than 1 seizure per 60,000 sessions. See TMS side effects.
Sham
A fake treatment that mimics the sound and feel of TMS without meaningful stimulation, used as a placebo in trials. Sham response in depression trials is large. That is why controlled trials matter.
sgACC
Subgenual anterior cingulate cortex, a deep brain region linked to mood. Prefrontal spots more out of sync with it seem to respond better, which is the idea behind connectivity-guided targeting.
Superbill
A detailed receipt with diagnosis and procedure codes that you can submit to your insurer for out-of-network reimbursement. See out-of-network TMS reimbursement.
Symptom provocation
Briefly triggering OCD symptoms right before each deep TMS session for OCD, as done in the pivotal trial. Described in TMS for OCD.
T to Z, plus numbers
Taper
Gradually reducing session frequency at the end of a course. The NeuroStar label adds a 3-week taper to 6 weeks of daily sessions. A 2025 consensus notes tapering has little empirical support.
Theta burst stimulation (TBS)
A pattern of very fast pulse triplets repeated five times a second, first described in motor-cortex research in 2005. Its intermittent form, iTBS, is used for depression.
TMS technician
The trained staff member who positions the coil and runs sessions. Physician oversight matters; Medicare in Brooklyn requires treatment under direct physician supervision. See who delivers TMS.
Train
A burst of pulses delivered in a row, followed by a pause. The standard 10 Hz protocol uses 4-second trains.
Treatment-resistant depression (TRD)
Depression that has not improved enough after adequate trials of treatment, usually at least two antidepressants. Definitions vary; what is treatment-resistant depression explains them.
Y-BOCS
The Yale-Brown Obsessive Compulsive Scale, a clinician-rated measure of OCD severity used in OCD TMS trials. See TMS for OCD.
510(k)
The FDA submission most TMS devices use: the maker shows the device is substantially equivalent to one already legally marketed, and FDA "clears" it. See what FDA clearance means.
5 cm rule
The original way to find the treatment spot: measure 5 cm forward from the hand area of the motor cortex. A neuronavigation check found it hit the intended region in only 7 of 22 people.
Where to go next
If a term here raised a question about your own situation, write it down for your TMS consultation. The TMS FAQ answers the most common questions in full sentences, and the TMS therapy page explains how to start a conversation about whether TMS fits you.
If you are thinking about suicide or are in crisis, call or text 988 (the 988 Suicide & Crisis Lifeline) or go to the nearest emergency room.
Sources
- Premarket Notification 510(k). U.S. Food and Drug Administration, 2026. fda.gov
- De Novo Classification Request. U.S. Food and Drug Administration, 2026. fda.gov
- De Novo Classification Request DEN070003 (NeuroStar TMS System). U.S. Food and Drug Administration, 2008. accessdata.fda.gov
- 510(k) K122288, BrainsWay Deep TMS System. U.S. Food and Drug Administration, 2013. accessdata.fda.gov
- 510(k) K251449 and 510(k) Summary, BrainsWay accelerated Deep TMS. U.S. Food and Drug Administration, 2025. accessdata.fda.gov
- 510(k) K260189, MagVenture Accelerated TMS (aTMS) Therapy System. U.S. Food and Drug Administration, 2026. accessdata.fda.gov
- 510(k) K173620 and 510(k) Summary, MagVita TMS Therapy System w/Theta Burst Stimulation. U.S. Food and Drug Administration, 2018. accessdata.fda.gov
- 510(k) K231926 and 510(k) Summary, NeuroStar Advanced Therapy System. U.S. Food and Drug Administration, 2024. accessdata.fda.gov
- De Novo Classification Request DEN170078 and De Novo Summary (Brainsway Deep TMS System for OCD). U.S. Food and Drug Administration, 2018. accessdata.fda.gov
- Efficacy of Adjunctive Deep Transcranial Magnetic Stimulation in Obsessive-Compulsive Disorder: A Randomized Sham-Controlled Study. Journal of ECT (Reddy, Goyal, Shreekantiah), 2026. pubmed.ncbi.nlm.nih.gov
- 510(k) K220177 and 510(k) Summary, Magnus Neuromodulation System with SAINT Technology. U.S. Food and Drug Administration, 2022. accessdata.fda.gov
- Daily left prefrontal transcranial magnetic stimulation therapy for major depressive disorder: a sham-controlled randomized trial. Archives of General Psychiatry (George et al.), 2010. pubmed.ncbi.nlm.nih.gov
- Efficacy and safety of deep transcranial magnetic stimulation for major depression: a prospective multicenter randomized controlled trial. World Psychiatry (Levkovitz et al.), 2015. pmc.ncbi.nlm.nih.gov
- Effectiveness of theta burst versus high-frequency repetitive transcranial magnetic stimulation in patients with depression (THREE-D): a randomised non-inferiority trial. The Lancet (Blumberger et al.), 2018. pubmed.ncbi.nlm.nih.gov
- Theta burst stimulation of the human motor cortex. Neuron (Huang et al.), 2005. pubmed.ncbi.nlm.nih.gov
- Transcranial magnetic stimulation in therapy studies: examination of the reliability of 'standard' coil positioning by neuronavigation. Biological Psychiatry, 2001. pubmed.ncbi.nlm.nih.gov
- An efficient and accurate new method for locating the F3 position for prefrontal TMS applications. Brain Stimulation (Beam et al.), 2009. pubmed.ncbi.nlm.nih.gov
- A randomized trial comparing beam F3 and 5.5 cm targeting in rTMS treatment of depression demonstrates similar effectiveness. Brain Stimulation (Trapp et al.), 2023. pubmed.ncbi.nlm.nih.gov
- A randomized trial of rTMS targeted with MRI based neuro-navigation in treatment-resistant depression. Neuropsychopharmacology (Fitzgerald et al.), 2009. pubmed.ncbi.nlm.nih.gov
- Efficacy of transcranial magnetic stimulation targets for depression is related to intrinsic functional connectivity with the subgenual cingulate. Biological Psychiatry (Fox et al.), 2012. pubmed.ncbi.nlm.nih.gov
- Canadian Network for Mood and Anxiety Treatments (CANMAT) 2023 Update on Clinical Guidelines for Management of Major Depressive Disorder in Adults. Canadian Journal of Psychiatry (Lam et al.), 2024. pmc.ncbi.nlm.nih.gov
- Drugs@FDA: NDA 211243 SPRAVATO. U.S. Food and Drug Administration, 2019. accessdata.fda.gov
- SPRAVATO (esketamine) nasal spray, Prescribing Information. Janssen / DailyMed, 2026. dailymed.nlm.nih.gov
- FDA warns patients and health care providers about potential risks associated with compounded ketamine products, including oral formulations, for the treatment of psychiatric disorders. U.S. Food and Drug Administration, 2023. web.archive.org
- Billing and Coding: Transcranial Magnetic Stimulation (A57528). CMS Medicare Coverage Database, 2026. cms.gov
- Transcranial Magnetic Stimulation, LCD L33398 (version 40). CMS Medicare Coverage Database, 2026. cms.gov
- Durability of antidepressant response to repetitive transcranial magnetic stimulation: Systematic review and meta-analysis. Brain Stimulation (Senova et al.), 2019. pubmed.ncbi.nlm.nih.gov
- Consensus review and considerations on TMS to treat depression: A comprehensive update endorsed by the National Network of Depression Centers, the Clinical TMS Society, and the International Federation of Clinical Neurophysiology. Clinical Neurophysiology (Trapp et al.), 2025. tmslab.org
- A systematic review and meta-analysis on placebo response to repetitive transcranial magnetic stimulation for depression trials. Progress in Neuro-Psychopharmacology and Biological Psychiatry (Razza et al.), 2018. pubmed.ncbi.nlm.nih.gov
- Real-world effectiveness of a single-day regimen for transcranial magnetic stimulation using Optimized, Neuroplastogen-Enhanced techniques in Depression (ONE-D). Research Square preprint (Vaughn et al.), 2024. doi.org
- Clinical TMS Society's Statement on Level of Evidence for Single-Day TMS combined with Medications. Clinical TMS Society, 2025. clinicaltmssociety.org
- Transcranial Magnetic Stimulation Retreatment for Recurrent Depression: A Large Real-World Multisite Cohort Study. Acta Psychiatrica Scandinavica (Lyndon et al.), 2026. pubmed.ncbi.nlm.nih.gov
- Hypomanic/manic switch after transcranial magnetic stimulation in mood disorders: A systematic review and meta-analysis. World Journal of Psychiatry (Miuli et al.), 2021. europepmc.org
- Stanford Accelerated Intelligent Neuromodulation Therapy for Treatment-Resistant Depression. American Journal of Psychiatry (Cole et al.), 2020. pubmed.ncbi.nlm.nih.gov
- Clinical outcomes in a large registry of patients with major depressive disorder treated with Transcranial Magnetic Stimulation. Journal of Affective Disorders (Sackeim et al.), 2020. pubmed.ncbi.nlm.nih.gov
- Class II Special Controls Guidance Document: Repetitive Transcranial Magnetic Stimulation (rTMS) Systems. U.S. Food and Drug Administration, 2011. fda.gov
- Seizures from transcranial magnetic stimulation 2012-2016: Results of a survey of active laboratories and clinics. Clinical Neurophysiology (Lerner et al.), 2019. europepmc.org
- Efficacy and Safety of Deep Transcranial Magnetic Stimulation for Obsessive-Compulsive Disorder: A Prospective Multicenter Randomized Double-Blind Placebo-Controlled Trial. American Journal of Psychiatry (Carmi et al.), 2019. pubmed.ncbi.nlm.nih.gov
- 510(k) K260402, Wave Neuroscience MeRT System. U.S. Food and Drug Administration, 2026. accessdata.fda.gov
- 510(k) K220127, NeuroStar (MDD with comorbid anxiety symptoms). U.S. Food and Drug Administration, 2022. accessdata.fda.gov
- Connectivity-guided intermittent theta burst versus repetitive transcranial magnetic stimulation for treatment-resistant depression: a randomized controlled trial. Nature Medicine (Morriss et al.), 2024. pubmed.ncbi.nlm.nih.gov
- Consensus Recommendations for the Clinical Application of Repetitive Transcranial Magnetic Stimulation (rTMS) in the Treatment of Depression. Journal of Clinical Psychiatry (McClintock et al.), 2018. pmc.ncbi.nlm.nih.gov
- Repetitive transcranial magnetic stimulation versus electroconvulsive therapy for major depression: a systematic review and meta-analysis. Progress in Neuro-Psychopharmacology & Biological Psychiatry, 2014. pubmed.ncbi.nlm.nih.gov
FAQs
What does rTMS stand for?
Repetitive transcranial magnetic stimulation. It means pulses are delivered repeatedly in trains, which is how TMS is used to treat depression.
What is the difference between TMS and deep TMS?
Deep TMS uses a helmet-shaped H-coil designed to reach a broader and somewhat deeper area. Standard TMS uses a flat figure-8 coil that focuses on a smaller spot. Both are cleared for depression.
What does motor threshold mean in TMS?
It is the lowest strength that makes your fingers or hand twitch when the coil is over the motor area. Your treatment strength is set as a percentage of it.
What is the difference between response and remission?
Response usually means your depression score dropped by at least half. Remission means your score fell below a cutoff that counts as essentially well.
Is iTBS the same as accelerated TMS?
No. iTBS is a fast pulse pattern that shortens each session to a few minutes. Accelerated TMS means several sessions per day. Some protocols, such as SAINT, combine both.
