How Cannabis Changes Gene Expression Through Epigenetics | Research

The takeaway

Cannabis exposure appears to alter DNA methylation patterns at genes involved in neurodevelopment and cellular survival, with potential links to psychiatric symptoms.

Researchers studying the biological mechanisms behind cannabis-related mental health risks, and clinicians interested in biomarker development.

37 studies showed cannabis alters methylation at genes including DRD2, COMT, and AKT1

What the researchers found

Across 37 included studies, cannabis exposure was most consistently associated with global hypomethylation and changes at specific genes related to dopamine signaling (DRD2, COMT), cellular function (AKT1, STAT3), and neural development (NCAM1, DLGAP2). These epigenetic changes were linked to depressive, anxious, psychotic, and addictive behavioral patterns.

Why it matters

Epigenetics offers a mechanism for how cannabis might produce lasting behavioral effects without changing DNA itself. Understanding which genes are affected could eventually identify biomarkers for psychiatric vulnerability.

The numbers in context

37 studies included from 178 screened. Nine performed epigenome-wide analysis. Reduced methylation was found at Cg05575921, DNMT1, DRD2, COMT, DLGAP2, Arg1, STAT3, MGMT, and PENK. Increased methylation was found at DNMT3a/b, NCAM1, and AKT1.

How the study worked

Systematic scoping review searching PubMed, Cochrane CENTRAL, and Web of Science through January 2022. Of 178 initial articles, 37 were included. Studies covered both human observational research and animal experimental designs examining epigenome-wide and gene-specific methylation changes.

What this study cannot tell us

Substantial variation in cannabis dosing, administration methods, and how use was measured across studies makes direct comparison difficult. Most human studies were cross-sectional, so the direction of causation remains uncertain. Animal model findings may not translate to humans.

How to read the evidence

Scoping review with heterogeneous study designs and inconsistent dosing across studies limits the strength of conclusions.

When this study was published

Published in 2024 with literature searched through January 2022.

The bigger picture

If cannabis-induced epigenetic changes prove to be reliable markers, they could help explain why some users develop psychiatric problems while others do not. The involvement of dopamine-related genes aligns with existing theories about cannabis and psychosis risk.

Questions still open

Are these epigenetic changes reversible after cannabis cessation?
Could specific methylation patterns serve as early warning biomarkers for cannabis-related psychiatric risk?

Common questions

Can cannabis change your genes?

Cannabis does not change DNA itself, but this review found it can alter how genes are expressed through epigenetic modifications like DNA methylation.

Which genes does cannabis affect?

The most consistent changes were found in genes related to dopamine signaling (DRD2, COMT), neural development (NCAM1), and cellular pathways (AKT1, STAT3).

Read the original research

Epigenetic effects of cannabis: A systematic scoping review of behavioral and emotional symptoms associated with cannabis use and exocannabinoid exposure.

Drug and alcohol dependence, 263, 111401

View on PubMed ↗Publisher’s paper ↗

Citation

Machado, Ana Sofia; Bragança, Miguel; Vieira-Coelho, Maria. (2024). Epigenetic effects of cannabis: A systematic scoping review of behavioral and emotional symptoms associated with cannabis use and exocannabinoid exposure.. Drug and alcohol dependence, 263, 111401. https://doi.org/10.1016/j.drugalcdep.2024.111401