TMS has been proven to be safe since it was first used in clinical research in the late 1990’s. The most commonly reported side effect related to treatment include mild headache, tingling and scalp discomfort; however, less than 5% of patients discontinue treatment due to side effects. There is a small risk of a seizure (approximately 1 in 10,000) occurring during treatment; however, this risk is no greater than what has been observed with oral antidepressant medications. While TMS has been proven effective in 2 out of 3 patients, not all patients will benefit from it. TMS does not worsen depression, but patients should be carefully monitored for any changes in behaviour.