In the October 2025 webinar, Professor Marta Di Forti, MD, MRCPsych, PhD, delivered an insightful presentation on the intricate link between cannabis use and psychosis. Drawing on large-scale meta-analyses and cross-European studies, she highlighted how factors such as cannabis potency, frequency of use, and genetic vulnerability interact to shape psychosis risk—particularly noting higher incidence rates in cities like Amsterdam and London. Dr. Di Forti also shared novel findings on cannabis-related DNA methylation changes impacting immune and mitochondrial systems, as well as the success of the Cannabis Clinic for Patients with Psychosis in improving outcomes through patient-centered care. Her talk emphasized the importance of harm-reduction strategies, individualized interventions, and policies grounded in scientific evidence.

As cannabis use among older adults continues to rise, Dr. Deepak Cyril D’Souza, Professor of Psychiatry at Yale School of Medicine, and his colleagues underscore an urgent need to better understand how cannabis impacts the aging brain. Their article, “Cannabis, Aging, and Cognition: An Urgent Need for Research,” highlights critical gaps in scientific knowledge and outlines a roadmap for future investigation.

While most cannabis research has focused on younger adults, Dr. D’Souza’s team notes that older adults differ in metabolism, neurobiology, and medication use—factors that may significantly alter how cannabis and its compounds, such as THC and CBD, affect cognition and brain health.

Preclinical findings suggest intriguing possibilities: in animal models, low doses of THC have been shown to reverse age-related cognitive decline and improve neuronal connectivity. However, the human evidence base remains limited, leaving many unanswered questions about both risks and potential therapeutic benefits.

Dr. D’Souza emphasizes that cannabis may have dual effects in aging—offering potential neuroprotective benefits at some doses, while posing cognitive risks at others. The article calls for well-designed, longitudinal studies in older adults that explore dosage, duration of use, and brain imaging outcomes to clarify these effects.

As cannabis becomes more accessible, this research agenda is not only scientifically pressing but a public health priority. Understanding the interaction between cannabis and aging will be essential to guide clinicians, inform policy, and ensure safe, evidence-based use among older populations.

Read the full article in Cannabis and Cannabinoid Research

The Yale Center for the Science of Cannabis and Cannabinoids continues to contribute to cutting-edge developments in the field of psychedelic science. In a recent publication co-authored by Dr. Deepak Cyril D’Souza, Professor of Psychiatry at Yale School of Medicine and a leading investigator at our center, the team tackles one of the most critical challenges in psychedelic research—maintaining effective blinding in clinical trials.

Blinding is essential to ensure that research results are unbiased and scientifically sound. However, in psychedelic studies, the unmistakable effects of substances such as psilocybin or LSD often make it clear to participants and researchers who received the active compound versus a placebo—potentially influencing results.

To address this, Dr. D’Souza and colleagues propose the use of innovative active placebos—agents that mimic some of the perceptual effects of psychedelics without reproducing their full therapeutic impact. These active placebos could help preserve blinding, minimize expectancy bias, and enhance the overall rigor of psychedelic research.

This publication reflects the YC-SCAN²’s commitment to advancing methodological excellence, transparency, and scientific credibility in the study of cannabinoids and psychedelics. By promoting improved trial design and research standards, our center continues to play a pivotal role in shaping the future of evidence-based psychedelic medicine.

Published in the International Journal of Neuropsychopharmacology (2025)