Cannabis containing 10% or more of the psychoactive compound THC (Delta-9-tetrahydrocannabinol), can alter the DNA (1^✔ ✔Trusted Source
Methylomic signature of current cannabis use in two first-episode psychosis cohorts

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A recent study published in Molecular Psychiatry has found that high-potency cannabis can make changes in a person’s genetic material.

Cannabis Use and DNA Changes in Different Individuals

The Effect of cannabis on DNA may vary between individuals. It was observed that people who are experiencing their first episode of psychosis react differently than those who have never had such experiences.

This difference in DNA alteration can be used for developing DNA blood tests that could help identify cannabis users at risk of developing psychosis. Blood tests can help the healthcare providers to take preventive measures.

Importance of Cannabis Research

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.

Senior author Marta Di Forti, Professor of Drugs, Genes, and Psychosis at King’s IoPPN said: “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. Our study is the first to show high potency cannabis leaves a unique signature on DNA related to mechanisms around the immune system and energy production. Future research needs to explore if the DNA signature for current cannabis use, and in particular one of the 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’). DNA methylation is a type of epigenetic change, which means it alters gene expression without affecting the DNA sequence itself and is considered a vital factor in the interplay between risk factors and mental health.

How Cannabis Use Affects DNA and Mental Health

The laboratory team at the University of Exeter conducted complex analyses of DNA methylation across the whole human genome using blood samples from both people who have experienced first-episode psychosis and those who have never had a psychotic experience. The researchers investigated the impact of current cannabis use, including frequency and potency, on the DNA of a total of 682 participants.

The analysis showed that frequent users of high-potency cannabis had changes in genes related to mitochondrial and immune function, particularly the CAVIN1 gene, which could affect energy and immune response. These changes were not explained by the well-established impact that tobacco has on DNA methylation, which is usually mixed into joints by most cannabis users.

Dr Emma Dempster, Senior Lecturer at the University of Exeter and the study’s first author said: “This is the first study to show that frequent use of high-potency cannabis leaves a distinct molecular mark on DNA, particularly affecting genes related to energy and immune function. Our findings provide important insights into how cannabis use may alter biological processes. DNA methylation, which bridges the gap between genetics and environmental factors, is a key mechanism that allows external influences, such as substance use, to impact gene activity. These epigenetic changes, shaped by lifestyle and exposures, offer a valuable perspective on how cannabis use may influence mental health through biological pathways.”

Dr Emma Dempster meta-analyzed data from two cohorts: the GAP study, which consists of patients with first-episode psychosis in South London and Maudsley NHS Foundation Trust, and the EU-GEI study, which consists of patients with first-episode psychosis and healthy controls across England, France, the Netherlands, Italy, Spain, and Brazil. This totaled 239 participants with first-episode psychosis and 443 healthy controls representing the general population from both study sites who had available DNA samples.

Most of the cannabis users in the study used high-potency cannabis more than once a week (defined as frequent use) and had first used cannabis at 16 years, on average. High-potency cannabis was defined as having a Delta-9-tetrahydrocannabinol (THC) content of 10 percent or greater. THC is the principal psychoactive constituent in cannabis.

Reference:

1. Methylomic signature of current cannabis use in two first-episode psychosis cohorts – (https://www.nature.com/articles/s41380-024-02689-0)

Source-Eurekalert