Everything you need to know about The History of TMS: From Faraday to FDA and Beyond — how it works, what it costs, and how to find a provider who actually knows what they're doing.

In 1831, Michael Faraday demonstrated that a changing magnetic field could induce an electrical current in a conductor. He was studying electromagnetic induction — not treating depression. But the principle he established is the same one that makes TMS possible.

It took more than 150 years from Faraday’s demonstration to the first magnetic stimulation of the human motor cortex. The path from there to FDA clearance and global clinical practice is a story of neuroscience, engineering, and the gradual acceptance that the brain, like any organ, could be modulated without drugs or surgery.

What You’ll Learn

• How Anthony Barker’s 1985 breakthrough created modern TMS technology
• The serendipitous discovery that TMS affects mood
• How FDA clearance in 2008 transformed the TMS landscape
• The expansion of TMS indications from depression to OCD, migraine, and beyond
• How the Stanford Neuromodulation Therapy protocol transformed what TMS can achieve

The Early Years: Finding the Right Tool

The first attempt to stimulate the brain magnetically came from Anthony Barker at the University of Sheffield in 1985. Barker’s device delivered magnetic pulses through a coil placed on the scalp, activating the motor cortex and causing muscle contractions in the hand. It was the first modern transcranial magnetic stimulation.

The early machines were crude by today’s standards — single pulse devices that could activate the motor cortex but not sustain the patterned, repeated stimulation needed for therapeutic applications. Within years, however, researchers had built repetitive TMS (rTMS) devices capable of delivering trains of pulses.

Early research quickly established that:

• Repeated stimulation at high frequencies (5-20 Hz) increased cortical excitability
• Repeated stimulation at low frequencies (1 Hz or less) decreased cortical excitability
• The prefrontal cortex was reachable and connected to mood circuits
• The technology was safe enough for human use

The Depression Discovery

The serendipitous observation that TMS could affect mood came in the 1990s. Researchers noticed that patients who received TMS for other purposes — motor mapping, neurological research — sometimes reported mood changes afterward.

This led to controlled trials. In 1995, George and colleagues at the Medical University of South Carolina published a seminal study showing that high-frequency TMS to the left dorsolateral prefrontal cortex produced significant antidepressant effects compared to sham stimulation. The effect was modest but real.

Over the next decade, larger trials followed. The consistency of findings — modest but significant antidepressant effects across multiple trials — built the case for FDA consideration.

FDA Clearance: The Turning Point

In 2008, the FDA cleared the first TMS device (NeuroStar) for treatment of major depressive disorder in patients who had not responded to at least one antidepressant medication. The clearance was notable for being based on a treatment with a novel mechanism — the first non-pharmacological, non-invasive neuromodulation device to receive clearance for a psychiatric indication.

The bar was low by today’s standards: only one adequate trial showing superiority over sham, with the primary outcome failing to reach statistical significance on the prespecified analysis. Critics noted this. Defenders argued it was appropriate given the unmet need in treatment-resistant depression.

But the clearance mattered enormously for the field. Insurance coverage followed FDA clearance. More manufacturers entered the market. More clinicians trained in TMS. The treatment became available at scale.

Subsequent clearances from other manufacturers (Magstim, MagVenture, BrainsWay) and additional indications (OCD, migraine, smoking cessation) expanded the reach of TMS technology.

The Indications Expand

2013: BrainsWay Deep TMS cleared for major depressive disorder

2018: BrainsWay Deep TMS cleared for OCD — the first TMS clearance for a condition other than depression

2019: Magstim cleared for anxious depression (depression with prominent anxiety features)

2020-2024: Multiple expansions for bipolar depression, specific pain conditions, and additional psychiatric indications

The expansion of indications reflects growing evidence and increasing comfort with the technology. Each clearance required separate clinical trials, building the evidence base incrementally.

The Accelerated Protocol Era

The biggest shift in TMS practice over the past decade has been the development and validation of accelerated protocols. The Stanford Neuromodulation Therapy protocol — 10 sessions of 1,800 pulses over 5 days, using neuronavigated targeting and accelerated delivery — produced remission rates of 79% in treatment-resistant patients in 2020-2021 studies.

The accelerated approach was not new — researchers had explored multiple daily sessions for decades — but the Stanford protocol provided the definitive efficacy data. The combination of better targeting, better dosing, and better scheduling transformed what TMS could achieve.

The Technology Evolves

TMS coil design has evolved substantially since Barker’s original single-coil device:

Figure-8 coils — the standard for 25 years, balancing focality and depth for cortical targets

Double-cone coils — angled wings that penetrate slightly deeper for larger or deeper cortical areas

H-coils (Deep TMS) — specialized geometry reaching subcortical structures for OCD and other indications

Multi-locus coils — emerging technology allowing dynamic targeting without physically moving the coil

Neuronavigation — MRI-guided GPS systems that track coil position relative to individual brain anatomy. Now standard at academic centers, still optional at many community clinics

The Current State

TMS is now practiced in hundreds of clinics in the United States and thousands worldwide. The evidence base includes hundreds of randomized controlled trials, multiple meta-analyses, and clinical practice guidelines from professional organizations including the American Psychiatric Association and the Clinical TMS Society.

The technology is more precise, the protocols are more effective, and the accessibility is greater than at any point in its history. The 40-50% non-response rate remains the central challenge, driving research into better targeting, better prediction, and better combination approaches.

Where TMS Is Heading

The next decade of TMS development will likely be defined by three themes:

Precision targeting. Personalized targeting based on individual brain connectivity — the AI-guided approaches discussed in our recent article — will become standard, improving response rates.

Personalized prediction. Machine learning models incorporating genetic, imaging, and clinical data will predict TMS response before treatment begins, allowing better patient selection and protocol matching.

New indications. Research is active in PTSD, bipolar disorder, schizophrenia (negative symptoms), Alzheimer’s disease (cognitive effects), autism, and addiction. Some of these indications will reach clinical trials; some will reach clearance.

The Faraday Lineage

The TMS in your clinic traces a direct technological lineage to Faraday’s demonstration of electromagnetic induction. The physics has not changed — changing magnetic fields still induce electrical currents. What has changed is 200 years of engineering, neuroscience, and clinical validation.

The treatment you might receive today is built on decades of work by hundreds of researchers who asked, one question at a time, whether this strange new technology could help the patients who had not been helped by anything else.

The answer, so far, has been yes — incrementally, imperfectly, but real.