repetitive transcranial magnetic stimulation | insightful nutrition

repetitive transcranial magnetic stimulation | insightful nutrition.

Repetitive Transcranial Magnetic Stimulation (rTMS) for Depression: What is it, is it safe, and does it work?

1) Part 1
2) Part 2

A new, non-invasive treatment for depressed individuals is garnering much interest… even though it has been around for almost 15 years. Repetitive transcranial magnetic stimulation (rTMS), is a non-invasive procedure which uses magnetic fields to stimulate nerve cells in the parts of the brain associated with mood control and depression. In short, rTMS is a non-invasive way to re-wire the brain. It all sounds very strange, but the procedure is being studied by the top medical schools in North America, and is offered in well-respected institutions such as Mayo Clinic. The therapy is now being used as an alternative for those who do not respond to or tolerate antidepressant medication.

Major depressive disorder (MDD) is one of the most prevalent mental illnesses in North America, and affects about 4 percent of Canadians annually.1 Although a number of drug therapy treatments are available, as many of 30 percent of patients fail to respond to conventional treatments2 and about 60 percent experience a relapse.3

The aim of the therapy is stimulation of the prefrontal cortex of the brain – the area associated with regulating mood. A black wire coil shaped like a figure 8 is held to the top of the head, just above the dorsolateral prefrontal cortex – the area of the brain connected to planning and organization. The prefrontal cortex has many connections to other parts of the brain including the hippocampus area which helps regulate emotions.

Turning My Brain Back On?
When the current goes through the wire, it sets up a powerful external magnetic field at 1 ½ Tesla – a strength similar to which one experiences with an MRI machine. This magnetic field excites the neurons underneath the coil. Your doctor will determine the amount of magnetic energy needed – your ‘motor threshold’ is the dose needed to get your fingers or hands to twitch.

The electromagnetic coil is switched on and off repeatedly, up to 10 times a second to produce a series of pulses which sound very much like a woodpecker tap. It is surmised that the pulsing current (3,000 pulses over a 37-minute session), jumpstarts underactive mood-regulating circuitry and cells. It also enlarges blood vessels, allowing more oxygen to get in.

The hoped-for result is that one can change the electrical pathways and events by which one processes and receives information.4

Doctors at this point are not certain whether it is better to target one or both sides of the brain. Nor have they determined how intense to make the electromagnetic field. If it is too strong, there is risk of causing a seizure, but if it is too weak, the treatment won’t work. For these reasons, the therapy is regarded as experimental, says Dr. Gary Hasey, who started the first therapeutic transcranial magnetic stimulation lab in Canada in 1997.5

“This is ground-breaking work”, says Dr. Jeff Daslalakis, a psychiatrist who runs the brain treatment and research program at the University of Toronto. “Studies show that at least 40 percent of these people improve.”6

FDA and Health Canada Approved
Transcranial Magnetic Stimulation was approved by Health Canada in 1997, and by the U.S. Food and Drug Administration in 2008. In Canada the treatment is available through the Toronto-based Centre for Addiction and Mental Health (CAMH). There, people come for 20-minute sessions, twice a week.

In the Canadian public healthcare system, rTMS is available in Toronto, Vancouver and Red Deer Alberta, but growing demand means that there can be long wait-times. At Toronto’s Centre for Addiction and Mental Health (CAMH), the wait is one year. The MindCare Centre, has offices in Vancouver, Toronto, Ottawa and Montreal, and is Canada’s only private clinic. Each session costs around CAD 250.00. An entire course of Acute Treatment consisting of 20-30 sessions and initial intake consultation is around around CAD 5,000 to 7,500. The course of treatment lasts two to three weeks. In Canada, the fees can be covered under insurance, on a case-by-case basis.

Does it Work?
In a recent double-blinded, randomized, industry-independent, multi-university, tightly controlled study, electromagnetic stimulation treatment accounted for remissions in 14 percent of antidepressant resistant patients, compared to 5 percent in the simulated treatment control group.7 Researchers from Columbia University, the University of Washington, and Emory University reported their findings in the May 2009 issue of the Archives of General Psychiatry. The study was funded by the National Institutes of Health.

A sample of 190 patients who had previously failed to respond to antidepressant medications received at least three weeks of randomized, controlled magnetic stimulations on weekdays for three weeks, with the rTMS magnet aimed at their brain’s left prefrontal cortex. Patients who responded to active treatment received up to three weeks of additional, blinded rTMS until they achieved remission. This group then received a combination of medications intended to maintain the treatment effect. The result was that they remained in remission for several months.

Study participants who failed to improve during the blinded phase, entered a course of open-label rTMS. Among those who had been in the active rTMS group, 30 percent of these ‘resistant treatment’ subjects achieved remission during this second phase.

According to Dr. Mark George, of the Medical University of Southern Carolina, who led the multi-unit research team, these findings suggest that some patients might need as many as 5-6 weeks of daily rMTMS treatment.

Least Invasive Brain-Stimulation Procedure for Depression
Unlike Vagus Nerve Stimulation or Deep Brain Stimulation, transcranial magnetic stimulation does not require surgery or the implantation of electrodes. Unlike electroconvulsive therapy (ECT), it does not require seizures or sedation with anaesthesia. ECT is associated with greatly increased risk, as well as temporary memory impairment.

Safety: Risks and Possible Side Effects
According to the Mayo Clinic, transcranial stimulation may produce minor short-term side-effects. These are considered mild, and typically improve after the first week or two of treatment. Common mild side effects can include:

  • Headache
  • Scalp discomfort at the site of stimulation
  • Tingling, spasms, or twitching of facial muscles
  • Light-headedness
  • Discomfort from noise during treatment

Uncommon side effects are rare, however they can include:

  • Seizures
  • Mania (particularly in people with bipolar disorder)
  • Hearing loss (due to inadequate ear protection during treatment

Before having the procedure, it is important to tell the doctor or healthcare provider if you are pregnant, (or thinking of becoming pregnant), and if you have any metal or implanted devices in your body. Transcranial therapy should not be used in such cases. You would also need to tell your doctor about any past injuries, history of seizures or mania, surgeries, and any other mental or physical health problems.

How does rTMS work with Clinical Nutrition Therapies?
Natural targeted nutritional therapies are very safe, and can be used alongside other therapies, however, prior to undergoing any treatment, always speak to the consulting doctor about any medications, over-the-counter medications, herbal supplements or vitamins you are using. As a courtesy, bring a typed list of what you are taking to your doctor’s appointment, being sure to include the brand name, the dosages, and how often you take them daily.

Does rTMS work for other Mental Health Conditions?
Repetitive transcranial magnetic stimulation has been shown to be an effective tool for the treatment of several neuropsychiatric disorders including schizophrenia.8, 9, 10 It can also be used to treat conditions ranging from strokes to anorexia, tinnitus, migraines, obsessive-compulsive disorder, chronic pain and Parkinson’s disease. The department of psychiatry at Yale School of Medicine is running study trials to investigate the use of rTMS in reducing activity in the areas of the brain responsible for ‘hearing’ voices. For further information, see:

According to the Mayo Clinic, transcranial magnetic stimulation is less likely to work if:

  • Psychosis (detachment from reality) is present
  • Your depression has lasted for four or more years
  • Previous electromagnetic therapy (ECT) has not improved depression symptoms


1 Stephen T, Joubert N. The economic burden of mental health problems in Canada. Chronic Dis Can2001; 22:18-23.
2 Pincus HA, Pettit AR. The societal costs of chronic major depression. J. Clin Psychiatry 2001;62(Suppl 6):5-9.
3 American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 4th ed. Washington: the Association; 1994.
4 Klein E, Kolsky Y, Puyerovsky M, Koren D, Christyakov A, Feinsod M. Right prefrontal slow repetitive transcranial magnetic stimulation in schizophrenia: a double-blind sham-controlled pilot study. Biol Psychiatry 1999;46:154-4.
5 Gary Hasey, MD, Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario.
6 Shim, Alex, “Brain Rewiring”, Macleans Magazine, 9 February 2009.
7 Nauert PhD, R.(2010). Electromagnetic Stimulation (rTMS) for Depression. Psyc Central. Retrieved on July 15, 2012, from
8 Klein E, Kolsky Y, Puyerovsky M, Koren D, Chistyakov A, Feinsod M, Right Prefrontal slow repetitive transcranial magnetic stimulation in schizophrenia: a double-blindsham-controlled pilot study. Biol Psychiatry1999;46:1451-4.
9 Hoffman RE, Hawkins KA, Geurorguieva R, Boutros NN, Rachid F, Carroll K, et al. Transcranial magnetic stimulation of left tempoparietal cortex and medication-resistant auditory hallucinations. Arch Gen Psychiatry 2003; 47:332-7.
10 Fitzgerald PB, Brown, TL, Marston NA, Daskalakis, ZJ, De Castella A, Kulkarni J. Transcranial magnetic stimulation in the treatment of depression: a double-blind, placebo-controlled trial. Arch Gen Psychiatry 2003; 60:1002-8.