Repetitive Transcranial Magnetic Stimulation (rTMS)

What is rTMS?

Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation technique used to treat individuals with certain psychiatric conditions. It is TGA approved for the treatment of depression. In some settings, it is being explored as a treatment for other conditions including generalized anxiety disorder, addiction, and chronic pain, and it has been FDA approved for treatment of obsessive compulsive disorder (OCD).

How does it work? Some parts of the brain work differently in psychiatric

conditions such as depression and OCD. TMS delivers targeted therapy to these

brain regions. TMS is a medical device that generates brief magnetic pulses that

painlessly and non-invasively stimulates the underlying brain region. When pulses of

TMS are delivered repetitively, this is called repetitive TMS {rTMS).

How does it work?

rTMS targets the left or right dorsolateral pre-frontal cortex (DLPFC) with high or low frequency, respectively, magnetic pulses. With high frequency, left-sided rTMS, we aim to stimulate the DLPFC, as it tends to have reduced activity on the left side in depression. This approach tends to help most with things like amotivation and malaise, but it improves depression more globally as well. With low frequency, right-sided rTMS, we aim to down regulate the DLPFC, as it tends to have heightened activity on the right side in depression. This approach tends to help most when there is considerable anxiety, but it improves depression more globally as well.

How effective is rTMS?

According to Miron et al. (2021), about 50% of people with treatment-resistant depression respond to rTMS (depressive symptom severity is halved), and about 30% of people go into remission (recover fully from depressive symptoms).

How long does it take?

A single TMS session will last about 30 minutes based on various treatment parameters. An outpatient course of treatment for depression usually consists of 20-35 treatments over the course of 5-7 weeks although this can vary depending on an individual's response.

What are the side effects? 

TMS is a well-tolerated procedure with few side effects. The most common side effects are scalp irritation underneath the magnet, headache, and/or fatigue. TMS is free from side effects caused by many antidepressants such as gastrointestinal upset, sexual dysfunction, weight gain, and dry mouth. The most serious side effect is seizures, but the risk of seizures is extremely low.

Who is TMS for?

TMS is a treatment consideration for anyone whose depression has not responded sufficiently to medication and psychotherapy. You cannot have TMS if you have metal plates in your head. Dental fillings and most piercings are okay.

Is TMS the same as ECT?

TMS and electroconvulsive therapy (ECT) are very different, although they are both neurostimulation techniques. The way that they stimulate brain cells is different, and the aim of stimulation is different. TMS does not require anaesthesia and does not involve the intentional production of a seizure. It stimulates the a specific region of the brain instead.