St. Michael’s Hospital and Arthur Sommer Rotenberg Suicide & Depression Studies Program

Depression affects over 264 million people globally and is a leading cause of disability. While there are various treatments available, they don’t work for everyone, and it often takes weeks to know if a medication is effective. Ketamine, initially used as an anesthetic, has shown promise in treating depression that doesn’t respond to other treatments. It works quickly, but there are gaps in our understanding of how it affects the brain and who will benefit most from it. Our project aims to fill these gaps by using advanced techniques like electroencephalography (EEG) and computational modeling. Specifically, the study will focus on a brain signal known as the auditory mismatch negativity (MMN), which is a marker of cognitive function and is impaired in depression. The study will model how ketamine changes this signal and link these changes to specific brain mechanisms.