Educational Disclaimer: This article is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified mental health professional with any questions you may have regarding a medical condition.
Table of Contents
- What Is Deep Transcranial Magnetic Stimulation?
- How Does dTMS Work? The Mechanism
- What Conditions Does dTMS Treat?
- What to Expect During dTMS Treatment
- Is dTMS Safe? Side Effects
- How Effective Is dTMS?
- Frequently Asked Questions
Deep transcranial magnetic stimulation (dTMS) is an FDA-cleared, non-invasive neuromodulation treatment for major depressive disorder (MDD) and obsessive-compulsive disorder (OCD). Using a specialized H-coil helmet, dTMS delivers magnetic pulses that reach deeper into brain tissue than standard TMS, stimulating neural circuits that are dysregulated in these conditions – without surgery, anesthesia, or systemic medication.
This article explains how dTMS works, what conditions it is FDA-cleared to treat, what treatment involves, and what the research says about its effectiveness.
What Is Deep Transcranial Magnetic Stimulation?
Deep transcranial magnetic stimulation (dTMS) is a form of neuromodulation – a category of treatments that use physical energy to modulate neural activity. Like standard transcranial magnetic stimulation (TMS), dTMS uses brief, focused magnetic pulses to stimulate neurons in targeted brain regions without the need for surgery, systemic medication, or anesthesia.
What distinguishes Deep Transcranial Magnetic Stimulation from standard TMS is its specialized H-coil design (developed by BrainsWay), which generates a magnetic field capable of penetrating up to 3–4 centimeters into brain tissue – compared to the approximately 2-centimeter depth reached by the standard figure-8 TMS coil. This greater depth of penetration allows dTMS to activate neural circuits that standard TMS may not reach as effectively.
The device is worn like a fitted helmet during treatment sessions, with the coil positioned over the scalp region corresponding to the brain area being targeted. The magnetic pulses pass painlessly through the skull and scalp, directly stimulating the underlying neural tissue.
How Does dTMS Work? The Mechanism
Magnetic Pulses and Neural Activation
When a magnetic pulse is delivered through the H-coil, it induces a small electrical current in the targeted brain region. This current is sufficient to depolarize neurons – causing them to fire – in a controlled, localized way.
In the treatment of major depressive disorder (MDD), stimulation is typically directed at the left dorsolateral prefrontal cortex (DLPFC) – a region that research has consistently shown to be hypoactive in individuals with depression. By repeatedly stimulating this region with high-frequency magnetic pulses, dTMS can increase its activity over time, producing changes in neural circuit function that correlate with antidepressant effects.
In the treatment of OCD, the target shifts to the anterior cingulate cortex (ACC) and supplementary motor area (SMA) – key nodes in the cortico-striato-thalamo-cortical (CSTC) circuit that is dysregulated in OCD. A specific protocol involving brief, clinician-guided symptom provocation before stimulation is used to engage this circuit during treatment, maximizing the therapeutic effect.
The Brain Mapping Step
Before a course of dTMS treatment begins, an individualized cortical mapping procedure is performed. This process identifies the precise cortical location that produces a specific motor response (called the motor threshold), allowing the treatment team to accurately calibrate the stimulation intensity and coil positioning for each individual. Accurate targeting is essential for treatment efficacy and safety.
How It Differs from Standard TMS
| Feature | Standard TMS | Deep TMS (dTMS) |
| Coil design | Figure-8 coil | BrainsWay H-coil |
| Depth of penetration | ~2 cm | ~3–4 cm |
| Breadth of neural activation | Focal | Broader, deeper distribution |
| FDA clearance (depression) | Yes (MDD) | Yes (MDD) |
| FDA clearance (OCD) | Yes (with H7 coil clarification) | Yes (H7 coil for OCD, 2018) |
What Conditions Does dTMS Treat?
FDA-Cleared Indications
The BrainsWay Deep Transcranial Magnetic Stimulation system has received FDA clearance for two specific indications:
- Major Depressive Disorder (MDD) – particularly for individuals who have not responded adequately to antidepressant medication
- Obsessive-Compulsive Disorder (OCD) – specifically using the H7 coil, which received FDA De Novo clearance in 2018
dTMS for depression is often considered for individuals who have not achieved adequate relief from multiple medication trials.
Research-Investigational Uses
Research is currently investigating dTMS and related neuromodulation approaches for a number of additional conditions, including PTSD, substance use disorders, anxiety disorders, and smoking cessation. These applications currently remain investigational – meaning research is ongoing, but they do not currently carry FDA clearance for these specific indications. Clinicians and patients should distinguish clearly between FDA-cleared uses and investigational uses.
What to Expect During dTMS Treatment
Understanding what a dTMS treatment course involves can help reduce anxiety and support informed decision-making.
Before treatment begins: A clinical evaluation determines eligibility, including a review of medical history, current medications, and screening for contraindications. The cortical mapping step establishes the individualized treatment parameters.
Each session: A typical Deep TMS treatment session follows this structure:
- The client is seated comfortably
- The H-coil helmet is fitted and positioned
- For OCD protocols: a brief, clinician-guided symptom provocation step engages the target circuit
- The stimulation phase lasts approximately 20 minutes
- The session concludes; clients can return to all normal activities immediately afterward
There is no sedation, no recovery period, and no systemic medication involved. Most clients drive themselves to and from appointments.
Sensations during treatment: Clients typically experience a repetitive tapping or clicking sensation on the scalp where the coil is positioned. Some describe a mild headache afterward, particularly early in the treatment course. These sensations are generally well-tolerated and tend to diminish as treatment progresses.
Treatment course: A standard dTMS treatment course for depression typically involves 20 to 36 sessions delivered over 4 to 6 weeks – usually 5 sessions per week. OCD protocols typically involve 29 sessions over 6 weeks. After the initial course, some individuals pursue maintenance sessions to sustain treatment benefits.
Is dTMS Safe? Side Effects
dTMS has a well-established safety profile, with decades of clinical use and extensive trial data supporting its tolerability.
Common side effects (typically mild and transient):
- Scalp discomfort or tenderness at the coil site
- Mild headache, particularly early in treatment
- Jaw tightening or facial muscle activation during stimulation
- Fatigue following sessions (uncommon)
Rare but serious risk:
- Seizure – the risk of seizure with TMS/dTMS is very low (estimated at less than 1 in 10,000 sessions in screened populations). All clients are carefully screened prior to treatment, and established safety protocols are followed throughout.
Contraindications (factors that may preclude Deep Transcranial Magnetic Stimulation):
- Metal implants in or near the head (cochlear implants, certain types of surgical clips, pacemakers near the treatment area)
- Personal or family history of seizure disorder – requires careful clinical evaluation
- Active psychosis – requires clinical evaluation before proceeding
- Pregnancy – requires clinical evaluation
dTMS is a regulated medical procedure. Appropriate screening by a qualified clinical team is essential before beginning treatment.
How Effective Is dTMS?
Clinical trial data support dTMS as a meaningful treatment option for both MDD and OCD – particularly for individuals who have not responded adequately to first-line treatments.
For Major Depressive Disorder: Multiple randomized controlled trials and real-world effectiveness studies demonstrate that dTMS produces statistically and clinically significant reductions in depressive symptom severity. Response rates (defined as 50% or greater improvement) and remission rates vary across studies and patient populations. Research suggests that effects may be durable following the initial treatment course.
For OCD: The pivotal BrainsWay clinical trial (Carmi et al., 2019) demonstrated that dTMS with the H7 coil produced significantly greater reductions in OCD symptom severity (measured by the Yale-Brown Obsessive Compulsive Scale, Y-BOCS) compared to sham treatment. Response rates were clinically meaningful.
It is important to note that individual responses to dTMS vary. Not all individuals respond, and treatment outcomes depend on many factors including illness severity, co-occurring conditions, and the quality of the comprehensive treatment plan. dTMS is most effective as a component of a comprehensive treatment approach – not as a standalone intervention.
Frequently Asked Questions
How is Deep TMS different from ECT (electroconvulsive therapy)?
ECT and Deep TMS are fundamentally different treatments. ECT uses electrical current passed directly through the brain to induce a controlled seizure; it requires general anesthesia and produces antidepressant effects through mechanisms that differ from TMS. Deep TMS uses magnetic pulses, does not induce a seizure, requires no anesthesia, and has no systemic effects. Deep TMS is generally better tolerated and has a less stigmatized profile, though ECT remains more rapidly effective for the most severe presentations and certain emergency situations.
Is Deep Transcranial Magnetic Stimulation covered by insurance?
Coverage for dTMS for MDD is increasingly available through major insurers, though coverage policies vary. Many insurers require documentation of inadequate response to antidepressant trials before approving dTMS. Coverage for OCD indications is more variable. It is advisable to contact your insurer directly, and the clinical team at Synchrony Brain Health can assist with documentation requirements.
How long do dTMS results last?
Research suggests that Deep Transcranial Magnetic Stimulation results are durable for many individuals. Some experience sustained benefit lasting 12 months or longer following a full treatment course. Some individuals benefit from periodic maintenance sessions. Long-term outcomes depend on the individual, the condition being treated, and whether Deep Transcranial Magnetic Stimulation is embedded in a broader, ongoing care plan.
What disqualifies someone from dTMS?
The primary contraindications are metal implants in or near the head, an active seizure disorder, and certain cardiac devices. A thorough clinical evaluation before treatment assesses for all relevant contraindications. Most people with depression or OCD who are medically appropriate candidates can be considered for dTMS.
Explore dTMS at Synchrony Brain Health
Synchrony Brain Health is equipped with the BrainsWay dTMS system and offers dTMS treatment for qualifying individuals with MDD and OCD. Our clinical team can evaluate whether dTMS is appropriate for your situation and help you understand how it might fit within a comprehensive treatment plan. For individuals who have not found adequate relief from dTMS or other interventions, complementary approaches such as neurofeedback therapy may also be discussed as part of an integrated care plan. A full clinical assessment report helps ensure the most precise, individualized treatment planning.
Find Synchrony Brain Health on Google Maps to connect with our clinical team.
This article is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.
Citations: Carmi, L., et al. (2019). Efficacy and Safety of Deep Transcranial Magnetic Stimulation for Obsessive-Compulsive Disorder. JAMA Psychiatry; BrainsWay FDA clearance documentation; Tendler, A., et al. (2023) dTMS clinical data.
