A groundbreaking study from McGill University has revealed a concerning link between cannabis use and reduced brain connectivity in young adults at risk for psychosis. This research, which highlights how cannabis exacerbates synaptic deficits, could help shape future psychosis treatments, particularly for symptoms like social withdrawal and lack of motivation that are poorly addressed by current therapies.
Cannabis and Brain Connectivity in At-Risk Youth
The research focuses on young adults between the ages of 16 and 30, including individuals who have recently experienced psychotic symptoms or are considered at high risk of developing psychosis. Using advanced brain scanning technology, researchers discovered that these at-risk individuals exhibited significantly reduced synaptic density—the crucial connections between neurons that allow for effective brain communication.
Dr. Romina Mizrahi, senior author of the study and a professor at McGill’s Department of Psychiatry, explained, “Not every cannabis user will develop psychosis, but for some, the risks are high. Our research helps clarify why.” The study suggests that cannabis disrupts the brain’s natural synapse refinement and pruning process, which is essential for normal brain development.
New Insights into Psychosis Treatment
The findings have implications for how psychosis, particularly its early symptoms, might be treated. While current medications primarily address symptoms like hallucinations, they are often ineffective against other critical issues like social withdrawal, impaired motivation, and difficulties in work or school environments. The study’s first author, Belen Blasco, a PhD student at McGill, noted, “Current medications largely target hallucinations, but they don’t address symptoms that make it difficult to manage social relationships, work, or school.”
By focusing on synaptic density, the researchers believe new therapeutic approaches could improve these aspects of patients’ lives. “We may eventually develop therapies that enhance social function and quality of life for those affected,” Blasco added.
Predicting Psychosis with Cannabis Use
Cannabis use has long been recognized as a risk factor for psychosis, which can lead to conditions like schizophrenia. However, this study is the first to measure the structural changes in the brains of those at high risk for psychosis in real time. The research team plans to explore further whether these observed brain changes could serve as indicators of impending psychosis, enabling earlier and more effective interventions.
The next phase of the research will delve deeper into whether the reduction in synaptic density can help predict who may develop psychosis, potentially opening doors for preventive treatments before the onset of more severe symptoms.
Reference
“Synaptic Density in Early Stages of Psychosis and Clinical High Risk” by M. Belen Blasco, Kankana Nisha Aji, Christian Ramos-Jiménez, Ilana Ruth Leppert, Christine Lucas Tardif, Johan Cohen, Pablo M. Rusjan, and Romina Mizrahi, published November 13, 2024, in JAMA Psychiatry. DOI: 10.1001/jamapsychiatry.2024.3608.
