Grant: Project Grant

Depression is an important public health issue, now ranked as the first cause of disability worldwide. It is currently estimated that around 300 million individuals around the globe and 1.76 million Canadians suffer from depression on any given year. Effective treatments exist for depression, such as antidepressants and psychotherapy, but many individuals will not respond to these approaches. In the last decade, Transcranial Magnetic Stimulation (TMS) has emerged as a safe, well-tolerated and effective treatment for this condition. TMS uses a powerful magnetic field to active neurons in the brain that are not functioning properly in depression. Currently, two types of TMS exist, either Repetitive or Deep TMS. Repetitive TMS uses a small coil causing only superficial brain stimulation, while Deep TMS uses a larger coil that can reach deeper parts of the brain. It is theorized that Deep TMS might be more effective than Repetitive TMS in depression, but more evidence is necessary. It is an important research question to resolve in order to increase the quality and the overall effectiveness of TMS in depression. Additionally, there is currently no way to determine if someone living with depression could benefit from TMS. Being able to predict if someone will respond or not to TMS before starting treatment could prevent useless interventions in people who have little odds of improvement and expedite remission in people who have good odds. We will therefore carry a large trial to compare both types of TMS. Our hypothesis is that Deep TMS will be more effective than Repetitive TMS. Participants will also undergo biomarker testing before treatment to help us predict the odds of responding to TMS.