Repetitive Transcranial Magnetic Stimulation (rTMS) for Treatment Resistant Depressive Disorder

Major Depressive Disorder (MDD) is one of the most prevalent mental illnesses in North America, in which 30% - 40% fail to respond to conventional treatment. Repetitive Transcranial Magnetic Stimulation (rTMS) has been shown to be an effective therapeutic tool for the treatment of MDD. This form of treatment involves a series of magnetic pulses directed to the brain for about 30 minutes. Importantly, such treatment is very safe and well tolerated. However, to date, most treatment studies show modest efficacy due to limitations, including: 1) treatments that are delivered to only one side of the brain; 2) treatment that does not directly target a specific brain region associated with depression; 3) treatments that are of short duration; 4) treatments that are of insufficient intensity; and 5) insufficient understanding of the brain mechanisms responsible for therapeutic effect. This study is designed to directly address all of these limitations, as well as explore brain mechanisms (e.g. cortical excitability) through which treatment is optimized.