Grant: Canada Postdoctoral Research Award (CPRA) program

Depression is a common mental health condition that affects nearly 2 million Canadians. It causes major disability and can disrupt daily life. About one in three people do not find relief from standard treatments such as medication or psychotherapy, making it urgent to find new and more effective options. Research shows that people with treatment-resistant depression often have overactivity in a deep brain region called the subgenual anterior cingulate cortex (sgACC), which helps control emotions. Calming this overactivity can improve mood and reduce symptoms. Brain stimulation using electrical currents can help restore balance, but most existing methods are either invasive (requiring surgery) or unable to reach deep brain areas like the sgACC. A newer technique, called transcranial Temporal Interference Stimulation (tTIS), can reach these deeper regions precisely without surgery. However, to be most effective, tTIS needs to be tailored to each individual. Our research uses computer simulations alongside data from an ongoing clinical trial to develop personalized approaches. First, we create computer models from each participant's brain scans to see how tTIS reaches the sgACC. Then, we test whether stimulation settings in the models are linked to improvements in brain function and depression symptoms. Finally, we explore whether adjusting stimulation settings for each person could enhance treatment effects. Because depression and treatment responses can differ by sex and gender, we collect this information from all participants and include it in our analyses to ensure results are broadly relevant. By advancing a more effective and personalized way to use brain stimulation, this research could transform depression treatment and bring new hope to people who have not found relief with standard care.