Deep transcranial magnetic stimulation (dTMS) is an advanced, non-invasive brain stimulation technique that uses electromagnetic fields to activate specific neural networks in the brain. This advanced neuromodulation treatment offers new hope for individuals struggling with treatment-resistant depression and other mental health conditions, particularly when traditional approaches haven’t provided effective relief. At Neuralia TMS in Perth, we deliver this innovative therapy using TGA-approved BrainsWay’s patented H-coil technology and evidence-based protocols.
Key Takeaways
- dTMS uses patented H-coil technology to reach 3 to 6 cm into the brain, targeting deeper structures than traditional TMS.
- Treatment is non-invasive, requires no anaesthesia, with no downtime between sessions.
- A systematic review and meta-analysis confirm dTMS effectively treats major depression, OCD, and anxious depression.
- Standard protocol involves 20-minute treatment sessions, 5 days weekly for 4 to 6 weeks (20 to 30 total sessions).
- Medicare covers eligible patients with treatment-resistant depression who’ve failed two medication trials.
What is Deep Transcranial Magnetic Stimulation (dTMS)?
Deep transcranial magnetic stimulation (dTMS) is a specialised form of repetitive transcranial magnetic stimulation (rTMS) that delivers electromagnetic pulses deeper and more broadly within the brain compared to conventional TMS therapy. The treatment uses patented H-coil technology contained inside a cushioned helmet that fits over the patient’s head.
The helmet enables the magnetic field to reach important brain structures up to 6 cm below the skull surface. This technological advancement represents a significant evolution from the traditional figure-8 coil used in standard rTMS, first developed in the 1980s.
Unlike medication that circulates throughout your entire body, dTMS precisely targets specific brain regions involved in mood regulation and behaviour. The magnetic pulses generated during treatment are similar in strength to those used in MRI machines, so it’s a safe and well-tolerated treatment option for most patients.
Advanced H-Coil Technology
The H-coil design is what truly distinguishes dTMS from other non-invasive brain stimulation therapies. This innovative technology allows for:
- Simultaneous stimulation of larger brain volumes
- Deeper penetration without increasing intensity to uncomfortable levels
- More uniform magnetic field distribution with less rapid decay
- Reduced positioning sensitivity compared to figure-8 coils used in traditional TMS
How Does Deep TMS Treatment Work?
Deep TMS works by generating short magnetic pulses that pass painlessly through the skull to stimulate specific brain regions associated with various psychiatric disorders. These magnetic fields, typically delivered at a frequency of 10 to 20 Hz, induce small electrical currents in the targeted brain tissue. These stimulate neurons and may help to normalise activity in underactive regions through the brain’s inherent neuroplasticity. For treating depression, dTMS typically targets the left dorsolateral prefrontal cortex (DLPFC), an area often showing reduced activity in people with major depressive disorder.
During a dTMS treatment session, patients sit comfortably in a chair while a cushioned helmet containing the H-coil is placed over their head. The coil delivers precisely calibrated magnetic pulses that penetrate 3 to 6 cm into the brain, compared to just the average 0.7 to 2 cm with standard repetitive TMS. This deeper reach is critical for stimulating the neural circuits involved in conditions like major depression and Obsessive-Compulsive Disorder.
Neural Mechanism of Action
The therapeutic effects of dTMS work through several mechanisms:
- Stimulating neuronal activity in underactive brain regions
- Modulating the release of neurotransmitters like dopamine and serotonin
- Increasing regional cerebral blood flow
- Promoting neuroplasticity through long-term potentiation (LTP)
- Normalising functional connectivity between brain networks
What’s the Difference Between Deep TMS and Standard TMS?
The primary difference between deep TMS and standard TMS is the depth and breadth of brain stimulation they provide. dTMS uses the specialised H-coil that can stimulate brain tissue up to 3 to 6 cm below the skull, while rTMS therapy with a figure-8 coil typically reaches only 0.7 to 2 cm. This deeper penetration allows dTMS to target brain structures that standard TMS simply cannot reach effectively.
Another key difference is the magnetic field distribution. The H-coil creates a broader, more widely distributed field, which improves the likelihood of stimulating the intended brain regions even with slight positioning variations. Standard TMS coils produce a more focused field that requires extremely precise positioning to be effective. A prospective multicentre randomised study comparing active dTMS versus sham dTMS demonstrated the advantages of this broader field coverage.
| Feature | Deep TMS | Standard rTMS |
|---|---|---|
| Coil Design | H-coil (helmet) | Figure-8 coil |
| Penetration Depth | ~3 to 6 cm | ~0.7 to 2 cm |
| Field Distribution | Broad, less focal | Narrow, more focal |
| Stimulation Volume | ~17 cm³ | ~2 to 3 cm³ |
| Positioning Error Sensitivity | Lower | Higher |
| Session Duration | 20 to 30 minutes | 20 to 40 minutes |
| Pulse Parameters | 18 Hz, 2-sec trains | Varies by protocol |
Theta Burst Stimulation Option
An advanced dTMS protocol called theta burst stimulation (TBS) is now available with some systems. This delivers bursts of 3 pulses at 50 Hz, repeated at 5 Hz, which more closely mimics natural brain rhythms. TBS sessions can be completed in just 3 to 10 minutes while potentially offering similar or enhanced efficacy of dTMS compared to standard protocols. The use of dTMS with TBS holds promise for treating unipolar depression with shorter treatment times.
Which Conditions Can Deep TMS Effectively Treat?
Deep TMS effectively treats several mental health conditions, with TGA approval supporting its use for major depressive disorder (MDD), Obsessive-Compulsive Disorder (OCD), anxiety, and more. For treatment of major depression, dTMS targets the left dorsolateral prefrontal cortex, an area often showing reduced activity in patients with depression. When treating OCD, the medial prefrontal cortex and anterior cingulate cortex are targeted instead, as these regions are involved in regulating compulsive behaviours.
Approved and Emerging Applications
- Major Depressive Disorder: First-line or after medication failure
- Treatment-Resistant Depression: After failure of 2+ antidepressants
- Obsessive-Compulsive Disorder: Particularly effective with symptom provocation technique
- Anxious Depression: Depression with prominent anxiety features
- Smoking Cessation: Targeting addiction-related brain circuits
Current research is investigating applications for PTSD, bipolar depression, chronic pain, multiple sclerosis fatigue, Parkinson’s Disease, and various addictions. These applications show promise in early randomised controlled trials but require further validation. The effect of deep TMS across these different conditions relates to its ability to modulate specific neural circuits involved in each disorder.
What Happens During a Deep TMS Treatment Session?
During a dTMS treatment session, you’ll sit comfortably in a chair while a trained technician places the treatment helmet containing the H-coil over your head. Your first session will include determining your “motor threshold” – the minimum stimulation needed to cause a small hand movement, which helps personalise your treatment intensity. This calibration ensures you receive the optimal dose (typically 100 to 120% of motor threshold) for treatment effectiveness while maintaining comfort and safety.
Treatment Protocol Breakdown
- Motor threshold determination (first session only)
- Coil positioning: Based on your condition’s target area
- Treatment delivery: Typically 36 two-second pulse trains with 20-second intervals
- Total pulses: Approximately 1,980 pulses per session
- Session duration: About 20 minutes of active treatment time
Each treatment session typically lasts 20 to 30 minutes in total. During treatment, you’ll hear clicking sounds and feel tapping sensations on your scalp as the magnetic pulses are delivered. You will be fully awake and alert throughout the procedure, and can resume all normal activities immediately afterwards. The dTMS protocol maintains consistent parameters across sessions to ensure treatment reliability.
Is Deep TMS Safe? What About Side Effects?
The safety of deep transcranial magnetic stimulation is well-established, with minimal side effects reported in clinical studies. A comprehensive review and meta-analysis confirm that dTMS is considered very safe, which is one of its major advantages as a treatment option. The most common side effects include mild scalp discomfort or headache during or after treatment, which typically resolve quickly and often diminish after the first few sessions.
The risk of seizure is extremely rare, estimated at less than 0.1% of patients. According to a 2015 study published in World Psychiatry, dTMS was associated with just one seizure reported, and this was because of a protocol violation.
Side Effect Profile
| Side Effect | Frequency | Description |
|---|---|---|
| Scalp Discomfort | Common (>10%) | Temporary sensation at stimulation site |
| Headache | Common (>10%) | Usually mild and resolves quickly |
| Jaw Pain or Twitching | Uncommon (1–10%) | Related to proximity of motor nerves |
| Neck Pain | Uncommon (1–10%) | Usually from positioning during sessions |
| Dizziness | Rare (<1%) | Transient and mild |
| Hearing Changes | Rare (<1%) | Prevented by wearing earplugs |
| Seizure | Very rare (~0.1%) | Extremely uncommon risk |
Unlike medications, dTMS doesn’t cause systemic side effects such as weight gain, sexual dysfunction, or fatigue. The efficacy and safety of deep transcranial magnetic stimulation have been demonstrated in multiple studies. In fact, research suggests it may actually improve certain cognitive abilities rather than impair them.
Specific warnings
Certain individuals are not suitable candidates for dTMS treatment, including those with:
- Metal implants in or near the head (excluding dental fillings)
- Implanted deep brain stimulation devices (pacemakers, neurostimulators)
- History of epilepsy or seizures
- Certain neurological conditions
- Pregnancy (though risk is theoretical rather than documented)
What Can I Expect from Deep TMS Treatment Results?
Most patients begin to notice improvement in their symptoms after 2 to 3 weeks of daily dTMS sessions, though the timeline varies between individuals. The outcomes of deep transcranial magnetic stimulation typically emerge during the treatment protocol, with many patients experiencing significant symptom reduction by the end of the standard 4- to 6-week treatment course. Improvement often continues even after the treatment series concludes.
Timeline of Improvement
- Weeks 1 to 2: Early responders may notice subtle changes
- Weeks 2 to 4: Most patients begin experiencing noticeable improvement
- Weeks 4 to 6: Full therapeutic effect typically emerges
- Post-treatment: Benefits usually maintain for 3 to 12 months
When comparing active dTMS to sham dTMS groups in clinical studies, the durability of dTMS effects is impressive. A multicentre randomised controlled trial published in World Psychiatry (2015) found response rates of 38.4% for active dTMS versus 21.4% for sham treatment, and remission rates of 32.6% versus 14.6%, respectively. According to the Clinical Global Impression scale used in many studies, approximately 30–50% of patients with treatment-resistant depression achieve remission, while many others experience meaningful symptom reduction even without complete remission.
Real-world clinical data has shown even more promising results in some settings. A large naturalistic study of over 5,000 patients across 103 clinical sites demonstrated response rates of 58% and remission rates of 28%, significantly higher than those observed in controlled trials. Additionally, Australian clinical data from over 1,100 patients shows response rates of 47% and remission rates of 31%, confirming the effectiveness of dTMS in real-world treatment environments.
Is Deep TMS Covered by Insurance in Australia?
In Australia, Medicare covers TMS therapy, including deep TMS, for eligible patients with treatment-resistant depression who meet specific criteria. The Medicare Benefits Schedule (MBS) typically requires that patients have tried at least two different antidepressant medications without adequate improvement before qualifying for coverage. This coverage was added to the MBS in November 2021, recognising TMS as an effective treatment for depression, and completely easing the cost of the treatment.
Many private health insurance providers in Australia also offer coverage for dTMS treatments, though the extent of coverage varies between insurers and specific policies. It’s advisable to contact your health insurance provider directly to confirm your level of coverage before beginning treatment. The effectiveness of deep transcranial magnetic stimulation for treatment-resistant depression has led to increasing insurance coverage globally.
Medicare Coverage Requirements
To qualify for Medicare coverage, patients must typically:
- Have a diagnosis of major depressive disorder
- Have failed to achieve adequate improvement with at least two antidepressant trials
- Be under the care of a psychiatrist who recommends the treatment
- Meet other specific clinical criteria determined by Medicare
Neuralia TMS: Overcome Depression Drug-Free
Deep transcranial magnetic stimulation represents a significant advancement in the treatment of major depression and other psychiatric disorders, particularly for those who haven’t responded adequately to traditional approaches. Its ability to reach deeper brain structures with a broader field of stimulation offers new possibilities for addressing treatment-resistant conditions.
At Neuralia TMS in Perth, we’re committed to providing this innovative treatment option using the latest technology and evidence-based protocols. With minimal side effects, no downtime, and demonstrated effectiveness, dTMS therapy offers a promising alternative for many patients seeking relief from challenging mental health conditions. Contact us to learn more about dTMS and rTMS, and what the best treatment for you will be.
What is Deep TMS? FAQs
How long does a full course of dTMS treatment take?
A standard dTMS treatment course involves 20 to 30 sessions over 4 to 6 weeks, typically with 5 sessions per week (Monday to Friday). This intensive schedule optimises the neuroplastic changes that lead to symptom improvement. Some patients may benefit from maintenance sessions after completing the initial course to extend the therapeutic effects of dTMS.
Will I need to stop taking my medications during dTMS?
Most patients continue their current medications during dTMS treatment. Deep transcranial magnetic stimulation combined with antidepressants may actually enhance effectiveness in some cases. Your treating psychiatrist will provide specific guidance about your medication regimen during your dTMS therapy.
How do I know if I’m a good candidate for dTMS?
Good candidates for dTMS typically include people with major depressive disorder, OCD, or anxious depression who haven’t responded adequately to medications or psychotherapy. To determine if dTMS is appropriate for your specific situation, you’ll need a comprehensive evaluation done by a psychiatrist experienced with neuromodulation treatments. This assessment will help determine if dTMS or another type of TMS could benefit you.
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