TMS therapy has been around for nearly 40 years. The technology was first demonstrated in 1985, when Anthony Barker and his colleagues at the University of Sheffield in the UK showed that a magnetic pulse delivered to the scalp could activate the brain’s motor cortex. That experiment launched decades of research, but it took until 2008 for TMS to receive its first FDA approval as a treatment for depression.
Early Experiments With Magnetic Stimulation
The idea of using magnetic fields to stimulate living tissue is older than most people realize. A French physician named Jacques-Arsène d’Arsonval first reported using a time-varying magnetic field to induce electrical currents strong enough to stimulate tissue back in 1896. But d’Arsonval’s experiments were crude, and the technology to focus magnetic energy precisely on the brain didn’t exist yet.
That changed in 1985 when Barker’s team in Sheffield built the first practical TMS device. By placing a magnetic coil against the scalp, they could generate a brief, focused pulse that passed painlessly through the skull and triggered nerve cells in the brain. The initial demonstration targeted the motor cortex, making a person’s hand twitch without any surgery, electrodes, or sedation. It was immediately clear the tool had potential for both brain research and clinical medicine.
From Lab Tool to Depression Treatment
For the first two decades after 1985, TMS was primarily a research instrument. Scientists used single pulses to map brain function, study nerve pathways, and understand conditions like stroke and epilepsy. Repetitive TMS (rTMS), which delivers trains of pulses rather than single ones, emerged as a way to produce longer-lasting changes in brain activity. Researchers began testing whether those changes could relieve symptoms of depression.
The pivotal trial that opened the door to clinical use enrolled 301 patients with major depression who had already failed at least one antidepressant medication. Patients received either real TMS or a sham treatment targeting the left prefrontal cortex, a brain region involved in mood regulation. The results showed statistically significant improvement in depression scores, particularly among patients who had failed no more than two prior medications. On the strength of these findings, the FDA cleared the first TMS device for treating medication-resistant depression in October 2008.
FDA Approvals Over the Years
Since that initial 2008 clearance, the list of approved uses has grown steadily:
- 2008: First clearance for major depressive disorder in adults who haven’t responded to antidepressant medication.
- 2013: A “deep TMS” device using a different coil design received clearance for depression. That same year, a handheld TMS device was cleared for treating migraine with aura.
- 2017: Deep TMS became the first device approved as an add-on treatment for obsessive-compulsive disorder (OCD) in adults. A separate device was also cleared for both acute and preventive treatment of migraine.
- 2018: The first devices using a faster protocol called theta burst stimulation received clearance for depression. This protocol delivers a full session in about 3 minutes instead of the traditional 37 minutes.
Multiple manufacturers now produce FDA-cleared TMS systems, and the number of approved devices continues to grow. Between 2008 and 2019 alone, more than a dozen distinct devices or protocols received clearance.
How Deep TMS Changed the Picture
Standard rTMS uses a figure-eight coil that stimulates a relatively shallow area of the brain’s surface. Deep TMS, developed using a different coil shape called an H-coil, can reach structures further below the surface without cranking up the intensity to uncomfortable levels. There are now more than 20 H-coil variations designed for different brain targets.
The first study treating medication-resistant depression with this deeper approach was published in 2009. Deep TMS eventually earned its own FDA clearances for both depression and OCD, giving clinicians more flexibility in choosing a treatment approach. In real-world follow-up data, about 93% of patients who responded to an accelerated deep TMS protocol maintained their improvement at six months.
When Insurance Started Covering TMS
Even after FDA clearance in 2008, getting insurance to pay for TMS was a challenge for years. Medicare formally began covering TMS for severe major depressive disorder on October 1, 2015, seven years after the first approval. Coverage requires a confirmed diagnosis of severe depression, documented failure of at least one medication trial or intolerance to psychiatric medications, and a treatment order written by a psychiatrist who has examined the patient in person. Most private insurers followed Medicare’s lead, though specific requirements vary by plan.
The Timeline at a Glance
From d’Arsonval’s 1896 experiments to Barker’s 1985 breakthrough, and from years of research trials to the 2008 FDA approval, TMS took over a century to move from concept to clinical reality. The pace has accelerated dramatically since then. In the span of just one decade (2008 to 2018), TMS went from a single approved use with a single device to multiple approved conditions, faster treatment protocols, and broader insurance coverage. The core technology is now nearly 40 years old, but its clinical applications are still relatively young.