Chapter 21 - Depression

In this episode of PsyQ, we dive into a groundbreaking 2025 study published in JAMA Psychiatry that uncovers the biological mechanism connecting cannabis use to an increased risk of psychosis. Utilizing neuromelanin-sensitive MRI as a noninvasive proxy for long-term dopamine function, researchers demonstrated that individuals with cannabis use disorder (CUD) exhibit significantly elevated signals in the substantia nigra and ventral tegmental area (SN/VTA) of the midbrain. Crucially, these elevations map onto the exact midbrain subregions associated with the severity of untreated psychotic symptoms, suggesting that heavy cannabis use directly impacts the “final common pathway” for the clinical expression of psychosis. The findings also reveal a clear dose-dependent association, where a higher burden of CUD symptoms correlates with stronger dopaminergic signals, offering a critical window into how persistent cannabis use alters the brain’s reward and psychosis circuitry.Reference* Ahrens, J., Ford, S. D., Schaefer, B., Reese, D., Khan, A. R., Tibbo, P., Rabin, R., Cassidy, C. M., & Palaniyappan, L. (2025). Convergence of Cannabis and Psychosis on the Dopamine System. JAMA Psychiatry, 82(6), 609-617. https://doi.org/10.1001/jamapsychiatry.2025.0432 This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com

This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit upathak.substack.com