ViewPoint: Treating Depression With a Magnet


By Peter Chow

The rates of depression have tripled over the last year, with over 25% of adults expressing some symptoms of depression.

Before the pandemic, the lifetime prevalence of major depressive episode in Canadians was 12.2%.

While depression was always a leading cause of mental illness and the leading cause of disability among people ages 15 to 44, it has become a worsening problem during the COVID-19 pandemic.

An increasing number of people are suffering from the symptoms of sadness, loss of interest in pleasurable activities, and impairments in sleep, appetite, energy, and concentration.

At its worst, depression can lead to feelings of hopelessness and suicidal thoughts.

While there are many effective treatments for depression, first-line approaches such as antidepressants and psychotherapy do not work for everyone.

In fact, approximately two-thirds of people with depression don’t get adequate relief from the first antidepressant they try.

Afterwards, each subsequent medication tried is even less likely to help than the one prior.

Patients end up cycling through many trials of antidepressant medications without finding relief.

Treatment-resistant depression (TRD) is defined as someone who has not responded to at least two antidepressant medications.

For these patients, the answer may not be a pill but instead a powerful magnet.

Transcranial magnetic stimulation or TMS is not a new treatment.

TMS was first cleared by the FDA in 2008 for treatment-resistant depression and can provide relief when traditional treatments have failed.

It later gained indications for migraine (2013), Obsessive-Compulsive Disorder (2018), and smoking cessation (2020).

But despite over 13 years as an available treatment, most patients and many doctors are not aware that it exists as a treatment option.

Unfortunately, this means TMS is being under-utilized

For several decades, electroconvulsive therapy (ECT or “shock therapy”) was the gold standard for treatment-resistant depression.

In fact, ECT is still considered to be the most potent and effective treatment for this condition, and it continues to be used regularly.

For many people with treatment-resistant depression, however, ECT can be too difficult to tolerate due to side effects on memory and cognition. For those individuals there is a newer treatment option called transcranial magnetic stimulation (TMS).

TMS is a neuromodulatory technique which applies magnetic pulses to the brain.  Applying several pulses of TMS in a row is called repetitive TMS or “rTMS.”

In 2008, the US Food and Drug Administration (FDA) authorized the use of rTMS for major depressive disorder (MDD).

TMS works by applying magnetic pulses to a specific area of the brain, the left dorsolateral prefrontal cortex (DLPFC).

This area of the brain is hypoactive or slowed in individuals with depression.

The magnetic pulses work to activate the area and stimulate normal brain activity, improving overall brain function and normalizing the production of important neurotransmitters like serotonin.

This allows the brain to heal naturally without the need for medications that artificially boost levels of neurotransmitters.

A TMS stimulator is the size of mini-fridge with various controls on it to adjust stimulation parameters such as pulse intensity, number of pulses, and pulse frequency. The TMS coil is held against the scalp by a mechanical arm.

TMS doesn’t require anesthesia and it is generally exceptionally well tolerated as compared to the side effects seen with medications and ECT.

The most common side effect is scalp discomfort, a sensation  similar to static electricity.

A rare but serious side effect is seizures, in about 1 out of every 10,000 people who receive rTMS..

Approximately 50% to 67% of people with treatment-resistant depression experience a clinically significant response with rTMS.  About one-third of these individuals experience a full remission, meaning that their symptoms go away completely.

These results, while encouraging, are not permanent. Like most other treatments for mood disorders, there is a high recurrence rate.

However, most rTMS patients feel better for many months after treatment stops, with the average length of response being a little more than a year. Most opt to come back for subsequent rounds of treatment.

Patients receive treatment Monday to Friday for 4 to 6 weeks, each session lasting 15 to 30 minutes.   Relief isn’t usually noticeable until the third, fourth, fifth, or even sixth week of treatment.

rTMS has been approved by Health Canada for major depressive disorder (MDD). It is also being studied as a treatment for other disorders such as:
•  some eating disorders (anorexia nervosa and bulimia nervosa)
•  obsessive compulsive disorder (OCD)
•  chronic pain

Repetitive transcranial magnetic stimulation (rTMS) is available at Toronto Western Hospital, part of the University Health Network  (UHN) in Toronto.

Over the last 10 years, rTMS at UHN at Toronto Western Hospital  has expanded to 4 stimulation suites and 18 full-time staff. As of October, 2015, the clinic has received over 1,6​00 community referrals and delivered over 20,000 sessions of stimulation. The clinic currently sees some 40 to 60 patients a day, making it one of the busiest in North America.

The Headway Clinic in Sudbury has been offering Repetitive Transcranial Magnetic Stimulation Therapy for over 13 years in the Greater Sudbury area and now also offers rTMS Therapy in North Bay, for treatment of “depression, anxiety, PTSD, OCD and even smoking cessation.”

Patients in southern Ontario can access rTMS therapy through Toronto Western Hospital, the Centre for Addiction and Mental Health and St. Joseph’s Hospital in Hamilton, but the service in Sudbury is the only one of its kind in Northern Ontario.

rTMS is also available at multiple clinics in Petoskey and Traverse City.

TMS can be life-altering and even life-saving.

Unfortunately, most patients and many doctors are not aware that it even exists as a treatment option.

Even though it has been available for 13 years, even many psychiatrists are not familiar with the application and potential benefits of repetitive transcranial magnetic stimulation.

Unfortunately, this means transcranial magnetic stimulation is grossly under-utilised by patients in Sault Ste Marie.


  1. Disappointingly I’ve found many doctors in Ontario are unaware of treatment options or eschew them completely simply due to a lack of understanding, awareness or personal stubbornness.

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