A groundbreaking study published in Molecular Psychiatry suggests that high-potency cannabis use may leave a distinct mark on DNA, potentially signaling an increased risk for psychosis. High-potency cannabis is defined as having a Delta-9-tetrahydrocannabinol (THC) content of 10% or more.
This research is the first to highlight the differing effects of cannabis on DNA among individuals experiencing their first episode of psychosis compared to those who have never had such experiences. These findings may pave the way for the development of DNA blood tests that could help identify cannabis users at risk for developing psychosis, enabling more effective preventative measures.
The study was funded by the Medical Research Council, the National Institute for Health and Care Research (NIHR) Maudsley Biomedical Research Centre, and the NIHR Exeter BRC.
Senior author Marta Di Forti, a professor of Drugs, Genes, and Psychosis at King’s College London’s Institute of Psychiatry, Psychology & Neuroscience (IoPPN), emphasized the urgent need for further research due to the rising prevalence of cannabis use, particularly high-potency varieties. “Our study is the first to demonstrate that high-potency cannabis leaves a unique signature on DNA related to immune system mechanisms and energy production,” Di Forti stated. “Future research should explore whether this DNA signature can identify those users most at risk for developing psychosis in both recreational and medicinal contexts.”
The researchers examined the effects of cannabis on DNA methylation—a chemical process that modifies gene activity without changing the DNA sequence. This epigenetic change is crucial in understanding how risk factors influence mental health.
Led by a team at the University of Exeter, the study analyzed DNA methylation across the entire human genome using blood samples from 682 participants, which included individuals who had experienced a first episode of psychosis and those who had not. The researchers investigated the impact of current cannabis use, including frequency and potency.
The results revealed that frequent users of high-potency cannabis exhibited alterations in genes associated with mitochondrial and immune function, particularly the CAVIN1 gene, which may affect energy levels and immune responses. Notably, these changes could not be attributed to the effects of tobacco, which is commonly mixed with cannabis in joints.
This study marks the first evidence that regular use of high-potency cannabis can leave a molecular imprint on DNA, specifically impacting genes related to energy and immune functions. Dr. Emma Dempster, a senior lecturer at the University of Exeter and the study’s first author, stated, “Our findings offer crucial insights into how cannabis use may alter biological processes. DNA methylation serves as a bridge between genetics and environmental factors, allowing external influences—such as substance use—to impact gene activity. These epigenetic changes, influenced by lifestyle and exposures, shed light on how cannabis use may affect mental health through biological pathways.”
Dr. Dempster meta-analyzed data from two cohorts: the GAP study, which involved patients with first-episode psychosis from South London and the Maudsley NHS Foundation Trust, and the EU-GEI study, which included patients with first-episode psychosis and healthy controls from several countries, including England, France, the Netherlands, Italy, Spain, and Brazil. This resulted in a sample of 239 participants with first-episode psychosis and 443 healthy controls.
Most cannabis users in the study reported using high-potency cannabis more than once a week, with an average first use at age 16.
You Might Be Interested In:
-
Research Highlights Importance of Feedback in Youth Mental Health Care
-
Understanding Why Some Children Develop PTSD and Anxiety After Trauma
