Schulich School of Medicine & Dentistry

Rami Hamati can’t help but feel concerned by the fact that cannabis stores have become as common as Tim Hortons outlets. “Research shows there’s a direct association between cannabis use and psychosis,” he said. “In Ontario, we’ve seen a significant increase in the number of individuals who develop psychosis as a result of problematic cannabis use since it was legalized six years ago.” With support from the new Schulich Postdoctoral Fellowship Program, Hamati has begun conducting research to illuminate the biological pathways responsible for this phenomenon – which could point the way to methods of protecting individuals who are vulnerable to psychosis. Part of the program’s inaugural cohort, Hamati recently joined the lab of Jibran Khokhar, a professor in anatomy and cell biology at Schulich School of Medicine & Dentistry, with co-supervision from adjunct professor Dr. Lena Palaniyappan, to investigate the causal role of the transmitter dopamine in the interaction between cannabis and psychosis. “Based on earlier research, we think cannabis may be acting on dopamine to produce psychosis,” Hamati said. Hamati’s interest in neuroscience began when he was a teen working in his parents’ pharmacy. Both pharmacists, they arrived in Canada just weeks before he was born. Hamati was fascinated by how some customers relied on medications for mental health. “I knew there was a connection between a substance or molecule and non-physical health, and I was really curious about how that works in the brain,” he said. “That’s kind of how I got into neurotransmitters.”  

Dopamine research a focus

As a master’s student in neuroscience at the University of Ottawa, Hamati studied how antidepressants work in the brain using animal models under Dr. Pierre Blier. He went on to complete his PhD at the University of Ottawa’s Institute of Mental Health Research, working in a human neuroimaging lab under Dr. Lauri Tuominen and Clifford Cassidy. “What tied all my work together in those eight years was the study of neurotransmitters, specifically dopamine,” he said. As part of his PhD training, Hamati developed expertise in different techniques to look at the dopamine system in the brain, including neuromelanin-sensitive magnetic resonance imaging (MRI). He was inspired to pursue postdoctoral training by a desire to better understand the connection between the brain and the mind. “Some people still have a hard time believing that there is a real connection,” he said. “If we’re able to demonstrate that link, it could help reduce stigma.” https://www.youtube.com/watch?v=UXi2ghu4r0k Hamati’s interdisciplinary background made him the ideal fit for a research proposal Khokhar and Palaniyappan had begun working on last year. “Support from the Schulich Postdoctoral Fellowship Program allowed us to have Rami in place ahead of the grant we just resubmitted,” Khokhar said. “ He’s already hit the ground running with our data sets.” Postdoctoral scholars are crucial to rapidly driving discoveries forward. Hamati is excited by the promise of the research in Khokhar’s lab. “In the human studies, I’ll be looking at whether neuromelanin-sensitive MRI can predict patterns of cannabis use in people with psychosis, or even their ability to abstain from use,” he said. “The animal work, meanwhile, allows us to explore whether cannabis is acting on dopamine to produce psychosis, and if so, how.” He points to the importance of sustained support for early-career scientists through the new fellowship program. “By offering donor-matched funding on top of existing support, this program helps close the salary gap and shows that our work is valued.” Khokhar said that support is crucial. “It helps sustain the excellence of the research enterprise at Schulich Medicine & Dentistry and Western and creates an environment where early-career researchers can thrive.” Learn more about how Western is optimizing health for all.