High Potency Cannabis Leaves Distinct DNA Mark, Linked to Mental Health
This discovery may enable DNA blood tests to help identify cannabis users more susceptible to psychosis, potentially informing future preventative approaches. As cannabis use becomes more prevalent, understanding its biological impact is critical, especially for mental health.
Key Facts:
- High-potency cannabis affects genes linked to energy and immune response.
- Frequent use leaves distinct DNA marks, potentially linked to psychosis risk.
- Findings could enable future DNA tests for psychosis susceptibility in cannabis users.
Published in Molecular Psychiatry, this is the first study to suggest that the use of high potency cannabis leaves a distinct mark on DNA, providing valuable insights into the biological impact of cannabis use.
Defining High Potency Cannabis: High potency cannabis is defined as having Delta-9-tetrahydrocannabinol (THC) content of 10 percent or more.
The research indicated that the effect of cannabis use on DNA is different in people with their first episode of psychosis compared to those who have never experienced psychosis. This suggests the potential for DNA blood tests to help identify cannabis users at risk of developing psychosis, informing preventative strategies.
The study was funded by the Medical Research Council, the National Institute for Health and Care Research (NIHR) Maudsley Biomedical Research Centre (BRC), and the NIHR Exeter BRC.
Marta Di Forti, Professor of Drugs, Genes, and Psychosis at King’s IoPPN, stated: “With the increasing prevalence of cannabis use and more availability of high potency cannabis, there is a pressing need to better understand its biological impact, particularly on mental health.”
“Future research needs to explore if the DNA signature for current cannabis use, and in particular the one of high potency types, can help identify those users most at risk to develop psychosis, both in recreational and medicinal use settings.”
Researchers explored the effects of cannabis use on DNA methylation—a chemical process detected in blood samples that alters how genes are functioning (whether they are switched ‘on’ or ‘off’). This mechanism is a type of epigenetic change, meaning it alters gene expression without modifying the DNA sequence itself, and is a crucial factor in understanding the interplay between risk factors and mental health.
The laboratory team at the University of Exeter conducted complex analyses of DNA methylation across the human genome using blood samples from a total of 682 participants—both from individuals who experienced first-episode psychosis and those who have never had a psychotic experience.
The impact of current cannabis use, including frequency and potency, was assessed. Importantly, the changes observed were not accounted for by the established effects of tobacco, which is commonly mixed with cannabis by many users.
“Our findings provide important insights into how cannabis use may alter biological processes. DNA methylation, bridging the gap between genetics and environmental factors, allows external influences, such as substance use, to impact gene activity.”
Dr. Emma Dempster meta-analysed data from two cohorts: the GAP study, which consists of patients with first episode psychosis in South London, and the EU-GEI study, which encompasses patients with first episode psychosis across various countries including England, France, the Netherlands, Italy, Spain, and Brazil. This totaled 239 participants with first episode psychosis and 443 healthy controls representing the general population.
Most cannabis users within the study used high-potency strains more than once a week (defined as frequent use) and had first consumed cannabis at an average age of 16. High potency cannabis was again defined as containing THC levels of 10 percent or greater, the principal psychoactive constituent of cannabis.
About this Epigenetics and Cannabis Use Disorder Research
Original Research:
“Methylomic signature of current cannabis use in two first-episode psychosis cohorts” by Marta Di Forti et al. Molecular Psychiatry
Abstract
Methylomic signature of current cannabis use in two first-episode psychosis cohorts:
The rising prevalence and legalisation of cannabis globally underscore the importance of understanding its biological impact, especially regarding mental health.
This study examined the effects of current cannabis use and high-potency cannabis on DNA methylation in two groups of individuals experiencing first-episode psychosis compared to control subjects.
Interestingly, an interaction model identified two sites significantly associated with current cannabis use, suggesting that first-episode psychosis status may moderate how cannabis affects DNA methylation.
These findings enhance our understanding of the epigenetic implications of cannabis use, highlighting crucial molecular pathways affected by cannabis exposure.
Discussion: Experts in the field discussed the implications of these findings. What are your thoughts? Share them in the comments below!