What is Deep TMS (dTMS)? How It Works, Cost, & What to Expect

What Is dTMS?

Deep transcranial magnetic stimulation (dTMS) is a relatively safe, non-invasive procedure in which a coil that carries an electric current is placed against the head, producing a magnetic field that penetrates the scalp, skull, and cerebrospinal fluid (CSF) and stimulates neurons in the brain to activate (i.e., fire). Stimulating groups of neurons in specific brain areas, like the left prefrontal cortex, is believed to activate neural circuits thought to be impaired in mental health disorders,  such as depression and obsessive-compulsive disorder (OCD).

Despite being generally well-tolerated and FDA-approved to treat MDD, OCD, smoking cessation, and what is colloquially referred to as “anxious depression” (i.e., MDD with specifier “anxious distress”), it is usually only recommended by providers and covered by insurance after traditional treatment methods are ruled ineffective. Magnets and electric current preclude some people from receiving this treatment — e.g., those with epilepsy or pacemakers — but dTMS providers can help determine if you meet the criteria.

dTMS vs. rTMS?

Transcranial magnetic stimulation (TMS) is the general term for using electricity and the magnetic field to activate groups of neurons in the brain. Repetitive TMS (rTMS) refers to the delivery of TMS in repeating pulses, the pattern and timing of which have different effects (e.g., stimulating vs. inhibiting). Conventional rTMS devices can generate a magnetic field that typically only penetrates a shallow and focal cortex area.

Deep TMS devices can generate magnetic fields that penetrate a deeper and broader area of brain tissue. Technically, dTMS can use a single pulse or repetitive pulses (specifically called “deep rTMS”), just like conventional rTMS, but uses a unique coil design with a broader reach and fewer targeting errors.⁴¹ Deep TMS can also be achieved through the combined use of conventional rTMS coils and neuroimaging (e.g., DTI, a technique to determine the direction molecules are moving), but that may be less practical for routine clinical use.²

Treatment factors that can affect the efficacy of dTMS and deep-rTMS include:

• The device: Conceptually, all TMS devices use electric current to generate a magnetic field which induces an electric current in the brain’s neurons. There are several companies that manufacture rTMS devices, but at present, Brainsway is the primary supplier of dTMS devices (which use a uniquely shaped H-coil).
• The shape of the coil: Several coil designs offer varying amounts of stimulation, depth, and spread (e.g., H-coil, figure-of-eight, double cone, round, etc.). The H-coil is uniquely designed to penetrate deeper into the brain, but its target is less focused, stimulating a wider area of brain tissue. There are variations of H-coils designed to target brain areas implicated in different disorders.
• Coil Orientation: The direction of the electric current and its resulting magnetic field, relative to the brain’s folded cortical tissue, influences the resulting brain response. The optimal direction for coil placement is such that it enables the current to penetrate a gyrus rather than move along the gyrus. The H1 dTMS coil can uniquely reach deeper into the folded tissue and achieves a better stimulation angle than conventional rTMS coils.
• Pulse characteristics: For both dTMS and conventional rTMS, the stimulation is provided in short pulses that can vary in delivery (i.e., single vs. multiple pulse trains), frequency (how many pulses per second), the shape of the pulse’s wave, intensity, total duration of pulse trains, and inter-train intervals (time duration between pulse trains). Just as timing and pauses are critical when a comedian delivers a punchline, these parameters affect the brain differently.
• Pulse frequency: High-frequency pulses (3Hz or greater) activate neurons, while low-frequency pulses (1Hz or less) inhibit neurons from firing.³ Changing frequency may help treat specific symptoms, like stimulating low activity brain areas and calming  regions with excessively high activity. One frequency pattern approved by the FDA for anti-depressant clinical use is called theta-burst stimulation (TBS) and involves small bursts of high-frequency pulses (e.g., 50Hz) delivered every 200ms.
• Intensity: TMS devices can generate varying current levels, as each person may require a different amount of absolute current for stimulation. By stimulating the motor area of the brain with gradually increasing intensity until one’s hand muscles contract (termed the motor threshold), relative intensity is established. In general, the higher the intensity (and frequency), the greater the risk for seizures.
• Target Location: Depending on what symptoms are being treated, the brain area targeted will vary. For example, the left prefrontal cortex is the target for depression, bipolar depression, negative symptoms of schizophrenia, and migraine, while the medial prefrontal cortex is targeted for PTSD and alcohol dependence. Targets are chosen with the hope of regulating the brain circuitry (e.g., reward/motivation circuit) in  that region.
• Targeting Errors: The most accurate way to identify the target location is by using fMRI (functional MRI, which measures brain activity) and TMS in the same session. However, most clinics do not have access to fMRI for routine clinical use. In these cases, less accurate estimates are established through measurement systems, neuronavigation systems (requiring a previous structural MRI scan), and motor threshold determinations to establish relative markers. Such estimations can be subject to error, so dTMS using the H-coil provides the advantage of stimulating a deeper and broader area of brain tissue, more likely to activate the desired target.

What Is dTMS Therapy Used to Treat?

Clinically, dTMS is only approved to treat a handful of conditions, but research studies abound with potential therapeutic effects for several more mental health and neurologic disorders.  As considerable overlap exists between the neural circuitry involved in different disorders (e.g., depression/anxiety, bipolar disorder/schizophrenia, addiction/schizophrenia), stimulation of one target brain area (e.g., dorsolateral prefrontal cortex) can improve symptoms across multiple disorders. Indeed, cognitive enhancement has often been observed, even when that wasn’t the primary goal of stimulation.⁴

Deep TMS is FDA-approved to treat disorders such as:

• Major Depressive Disorder (MDD): BrainsWay dTMS was cleared in 2013 to treat MDD by targeting the dorsolateral prefrontal cortex in individuals resistant to traditional treatment approaches.
• Anxious Depression: While dTMS has not yet been cleared by the FDA to treat anxiety disorders, it was approved in 2021 to specifically treat what is colloquially referred to as “anxious depression,” which is depression with comorbid anxiety symptoms, sometimes diagnosed as MDD with specifier “anxious distress.” One study showed that symptom relief lasted for 16 weeks with stimulation of the left dorsolateral prefrontal cortex.
• Obsessive Compulsive Disorder (OCD): Brainsway dTMS was approved to treat OCD, and is considered the most effective type of TMS for OCD. In 2017 for individuals resistant to conventional  medication and psychotherapy. Targeting the medial prefrontal and anterior cingulate cortex with BrainsWay’s H7-coil improved symptoms in 38% of participants with OCD for about a month after treatment.⁵
• Smoking Addiction: BrainsWay’s dTMS was approved by the FDA in 2020 to aid in smoking cessation and is believed to help stimulate dopamine circuits involved in craving, which are impaired in addiction. Applying TMS to the left dorsolateral prefrontal cortex and medial frontal cortex can increase dopamine and reduce craving, thus aiding cessation. While it is currently only approved for smoking addiction, it may be useful for other substance misuse disorders with further research.⁶

While dTMS has only been approved by the FDA to treat a handful of conditions in the United States, it has been approved to treat many more in Europe (i.e., CE Marked), including Alzheimer’s disease, autism, bipolar disorder, chronic pain, multiple sclerosis (MS), Parkinson’s disease, post-stroke rehabilitation, post-traumatic stress disorder (PTSD), and schizophrenia (negative symptoms and auditory hallucinations). Although not yet approved in the U.S. or Europe, numerous research studies have shown the efficacy of dTMS for treating anxiety disorders (e.g., generalized anxiety disorder), occupational stress, and tinnitus.

Research supports the potential use of Deep TMS to treat other disorders, such as:

• Parkinson’s Disease:  The use of dTMS to treat Parkinson’s disease has been mixed, but some studies have demonstrated improvement in motor, postural and motivational symptoms when used as an add-on to  medication .^7,8
• Multiple Sclerosis: Deep rTMS has shown promise in treating the fatigue that affects an estimated 90% of individuals with MS, with the prefrontal cortex and motor cortex as areas of interest in recent research.⁹
• Autism Spectrum Disorder (ASD): Research on the use of dTMS in ASD is limited, but one study found that stimulation of the dorsomedial prefrontal cortex with dTMS improved social relating and reduced self-oriented anxiety during emotionally difficult social situations.¹⁰
• Alzheimer’s Disease (AD): While TMS is not a cure for Alzheimer’s disease by any means, dTMS, and more extensively rTMS, have shown promise for improving cognitive function in patients with mild to moderate severity for at least the treatment period by stimulating dorsolateral prefrontal cortex. Deep TMS may be more effective than rTMS for AD and other neurodegenerative diseases where the cortical surface of the brain may be a greater distance from the skull.^11,12,13,14
• Bipolar Disorder: Deep TMS to the left dorsolateral prefrontal cortex has been shown to improve depressive symptoms and global functioning in treatment-resistant individuals with bipolar disorder. However, the effect was relatively short-lived and gradually waned over the month following treatment.¹⁵
• Post-Traumatic Stress Disorder (PTSD): Targeting brain regions involved in emotional regulation and  controlled tasks (e.g. medial prefrontal cortex, right dorsolateral prefrontal cortex) that are also connected to brain regions that process fear (e.g., amygdala) have been effective in providing symptom relief to persons with PTSD, lasting several months, but potentially up to a year.^16,17,18
• Schizophrenia: Schizophrenia has a broad array of symptoms and variability between individuals. To date, most studies have found dTMS to relieve negative symptoms, such as the lack of interest and interaction, lack of motivation, and inability to feel pleasure, by stimulating the left prefrontal cortex and auditory hallucinations by targeting the temporoparietal junction.^19,20
• Chronic Pain: TMS may be useful for giving short-term pain relief (less than 3 months) for conditions like central pain, peripheral nerve disorders, fibromyalgia, and migraine, by both targeting cortical areas like motor cortex and related circuits involved in pain (e.g., areas that give rise to depressive symptoms which can exacerbate pain). Deep TMS has not yet been approved by the FDA to treat chronic pain in the US, but it has been CE Marked for use in Europe.²¹
• Post-Stroke Rehabilitation: Stroke can result in myriad functional impairments; dTMS has shown promising results to enhance recovery of motor, language, and affective function by stimulating respective affected brain regions. ^22,23,24
• Anxiety: Targeting the insula and prefrontal cortex with dTMS relieved anxiety symptoms for people with occupational stress and generalized anxiety disorder. However, other mixed research findings have held back FDA approval.
• Tinnitus: Deep TMS applied to the temporoparietal junction provided relief for individuals with tinnitus, an auditory sensory disorder affecting 10-15% of the population.^25,21,26
• Sleep Disorders: Although dTMS is far from being used therapeutically to treat sleep disorders, research suggests potential as an alternative treatment for restless leg syndrome, obstructive sleep apnea syndrome, and insomnia. Several studies have also demonstrated how TMS can reverse or stave off cognitive deficits caused by sleep deprivation.^27,28,29
• Obesity: Stimulation of brain areas involved with craving and impulsivity (e.g., insula, prefrontal cortex) has decreased impulsivity and BMI (body mass index) in individuals with obesity. The indicated circuit is likely similar to that implicated in addiction.^30,31,32,33

What to Expect from a dTMS Session?

Like conventional TMS, dTMS treatment is an intensive daily treatment that can be time-consuming and requires commitment. The treatment course may vary slightly depending on the symptom(s) being treated but typically comprises daily 20-minute sessions, five days per week, for up to 6 weeks, followed by a taper period of fewer weekly sessions for 3 weeks.

A dTMS treatment will likely involve the following:

• Location: Deep TMS usually takes place in an outpatient office or clinic, though it can be a hospital setting, especially for clinical research trials.
• Evaluation: Before treatment, you will be asked a series of questions to help the clinicians determine if dTMS is a safe and efficacious treatment for you to receive.
• Procedure Preparation: This procedure is non-invasive and does not require any surgery, needles, or other penetration of skin, nor anesthesia. You will be awake for the entire procedure. Measurements of your head may be taken to help identify your personal target location for stimulation.
• Setting: During a treatment session, you will be seated in a comfortable chair. As the procedure involves a magnetic field, you will not be able to bring any ferrous metal (jewelry, keys, glasses) into the room. At this point, earplugs will be placed since the treatment can be loud.
• Device Placement: The dTMS coil in the form of a cushioned helmet or panel will be placed against your scalp at a location specified to treat your symptom(s). Once the coil is placed, you must stay still, but you may be allowed to talk or read if your head doesn’t move.
• Personalized Target: As brain shape and size vary between individuals, there are several methods that the clinician may use to determine the target to stimulate. Some methods require head measurements, while others require prior neuroimaging. Since dTMS stimulates a broader area than conventional TMS, the target need not be as precise.
• Determining Intensity: The clinician will stimulate your motor cortex to identify your “motor threshold” – i.e., the pulse intensity that will cause your hand to contract. Your treatment intensity will be relative to this value (usually 80% to 120% depending on the condition). This threshold can change with sleep deprivation, medication, alcohol or drug use, so you must notify the clinician before a session if there’s been a change to any of these factors between sessions.²⁸
• Sensations: As the treatment begins, you will hear loud, repetitive noises despite wearing earplugs. You may experience tapping or clicking sensations against your scalp. Some individuals have described this as a light, repetitive tapping or knocking on the head.
• Daily Activity: You can resume your daily activities immediately after each session, and generally, there is no recovery period or restrictions on driving or operating machinery unless a seizure occurs as a side effect.
• Subsequent Sessions: The stimulation parameters are determined during the first session and need not be repeated every session unless there have been changes to sleep or substance use (including medications) that may impact the motor threshold. Subsequent daily sessions are usually briefer than the first session.²⁸
• Monitoring Effects of Treatment: There is variation in how different people respond to treatment. With feedback, parameters may be adjusted, but generally, improvement is not felt for the first few weeks of treatment. After the final session, symptom relief may last weeks to months, with some reporting lasting effects for 1 year. In some cases, brush-up sessions may be recommended when treatment effects wane.

Who Administers dTMS?

Deep TMS is administered by specially trained healthcare professionals such as psychiatrists, neurologists, psychologists, and clinical technicians. The ability to prescribe and offer dTMS varies from country to country. Within the US, psychiatrists can prescribe and use dTMS nationwide, but authority for other healthcare professionals (e.g., physicians, nurse practitioners, physician assistants, clinical psychologists) varies from state to state.

How Much Does dTMS Cost?

Typically, each session can cost at least $250, but the total cost will vary depending on the treated condition. For example, dTMS for migraines requires 3 sessions per week for 4 weeks, while major depressive disorder requires 5 sessions per week for up to 8 weeks. Thus, the total cost can end up ranging from $3,000 to $11,000 as a rough estimate based on average documented costs.³⁴

Most major insurance companies (e.g., United Healthcare, Empire, Optum, Carelon, Aetna, Medicare) will cover TMS treatment if you are eligible and have already resisted a traditional treatment option like medication and/or psychotherapy. You may consider contacting your insurance company to find out what mental and behavioral health treatments are covered by your plan and what your deductible, copay or coinsurance costs would be.

What Are the Potential Side Effects of dTMS?

Deep TMS is generally considered a safe and well-tolerated treatment option, but as with any medical procedure, it can have side effects. When they do occur, side effects typically subside shortly after the session, however, rarely, they can last longer (e.g., seizure activity or mania in the case of bipolar disorder treatment). Specialists take precautions to minimize the risk for side effects by carefully determining treatment parameters (e.g., intensity and frequency of pulses) and screening for contraindications.

Some potential side effects of dTMS include:

• Headaches (note that despite this side effect, TMS may help treat migraine pain)
• Seizures
• Dizziness
• Syncope (passing out)
• Tingling sensations
• Scalp discomfort and mild pain
• Muscle twitching
• Fatigue
• Anxiety
• Insomnia
• Jaw pain
• Back and neck pain
• Damage to the implanted device (e.g., pacemaker)
• Hearing loss (although earplugs are worn to prevent this)
• Manic episodes (in individuals with bipolar disorder)

Who Can Not Receive dTMS Treatment?

Before receiving dTMS, individuals must be screened to ensure their eligibility and safety. While specific contraindications may vary depending on the condition being treated (e.g., history of frequent headaches), other contraindications are more critical (e.g., seizure history, pacemaker). The healthcare professional will ask questions before treatment and, in some cases, require clearance from your medical team to determine if dTMS is a viable option for you.

You may need to consider an alternative to dTMS if you:

• Are pregnant or nursing
• Have implanted medical and electronic devices (stents, stimulators, pacemakers, cardioverter defibrillators, cochlear implants, etc.)
• Have any other metal device or object in the body (bullet fragments, metal plate, etc.),
• Have a history of seizures/epilepsy
• Have another medical condition that may put you at risk for a seizure
• Have brain damage from illness or injury
• Experience frequent or severe headaches (though sometimes dTMS can paradoxically be a treatment for migraine pain)
• Do not meet DSM criteria for the FDA or ICD criteria for the CE Marked (Europe) approved condition to be treated
• Have not already tried and shown resistance to traditional treatments (e.g., medication, psychotherapy)

Is dTMS Therapy Effective?

Deep TMS has been most extensively studied clinically for treating depressive symptoms and has demonstrated enhanced efficacy over conventional rTMS methods. It is most effective with antidepressant medication (in the case of MDD) or psychotherapy, suggesting a synergistic effect with other concurrent treatments even if they weren’t effective on their own.^35,36,37

While dTMS seems overall promising for treating a wide range of conditions, much research is still needed to refine the parameters that optimally alleviate specific symptoms for a long enough time that the time invested in this intensive treatment is worth it for the individual and potential insurance companies covering treatment. For the few conditions that the FDA has approved dTMS to treat, it does qualify as a good option for eligible cases for whom traditional treatments fail to provide symptom relief.^38,39

Is Deep Transcranial Magnetic Stimulation More Effective Than Electroconvulsive Therapy (ECT)?

Electroconvulsive Therapy (ECT) is a treatment mainly used to treat severe cases of MDD, in which an electrical current is used to directly induce seizure activity in the brain via scalp electrodes, stimulating neuronal activity in underactive regions. While ECT requires anesthesia before inducing seizure activity and can result in cognitive side effects like memory loss, dTMS uses a magnetic field to stimulate brain activity in a well-tolerated, non-invasive way, without anesthesia and cognitive side effects. In fact, dTMS has been shown to improve cognition even when that was not the intent of treatment.

ECT and dTMS treatments are intensive and require commitment. ECT sessions last about an hour, three times per week, for about a month. dTMS sessions are shorter, as there is no anesthesia and recovery time needed, but are more frequent for at least a month and sometimes longer. Even though ECT is more effective, more patients prefer dTMS, which has fewer side effects. However, ECT may be a viable option for individuals who have a contraindication for dTMS.⁴⁰

Where to Get dTMS Therapy

The leading company providing dTMS devices is BrainsWay, and they offer a directory for finding a dTMS provider near you. You may want to consult a psychiatrist to determine if dTMS is a viable option for you. If you have trouble finding a psychiatrist near you, you can search online psychiatrist directories or ask your healthcare provider. Lastly, you can search a clinical trial database for research studies to participate in if you find that clinical options for your condition are unavailable.

History of dTMS

Transcranial magnetic stimulation (TMS) has been used in clinical research for decades, with clinical trials for treating MDD starting in the 1990s. The FDA approved using the Neuronetics Neurostar TMS system to treat MDD in 2008. Since then, the field of TMS bloomed with novel protocols, parameters (e.g., theta burst stimulation, rTMS), and devices by companies like Magstim, TeleEMG, Nexstim, and Magventure.

The most recent advances in the evolution of  TMS devices and protocols have come in the form of a unique coil design by BrainsWay called the H-coil. Cleared by the FDA in 2013, the H-coil allowed for deeper, broader penetration of the brain, called deep TMS (dTMS). Since its initial approval for the treatment of MDD, BrainsWay’s dTMS has gained clearance to treat other mental health conditions like OCD (in 2017), smoking addiction (in 2020), and comorbid MDD with anxiety (in 2021).⁴¹

Final Thoughts

While dTMS is not suitable for everyone, if you’re struggling with a treatment-resistant disorder, it may be worth looking into this option. Many individuals who have not found symptom relief with conventional therapies like medication or psychotherapy have reported positive outcomes with dTMS. Given that it is a relatively safe and well-tolerated alternative treatment, it may be a viable option to explore.