Adolescent cannabis use is linked to DNA methylation changes in immune cells that overlap with psychosis-related genes
A methylome-wide study of 703 adolescents found cannabis use associated with specific DNA methylation changes, including patterns in T cells and monocytes that overlap with brain tissue findings from psychosis research.
Quick Facts
What This Study Found
45 significant methylation sites were identified in whole blood, plus 32 additional in cell-type analyses. B-cell methylation overlapped with genetic studies of educational attainment and intelligence. T-cell and monocyte results overlapped with brain tissue methylation findings from psychosis studies.
Key Numbers
703 adolescent samples; 45 significant whole-blood CpGs; 32 additional cell-type-specific CpGs; significant overlap with psychosis and intelligence genetic studies
How They Did This
Methylome-wide association study using enrichment-based sequencing in 703 adolescent samples from the Great Smoky Mountain Study, with cell-type-specific analyses for granulocytes, T cells, B cells, and monocytes.
Why This Research Matters
This provides the first epigenomic evidence linking adolescent cannabis use to molecular changes that overlap with psychosis-related pathways, offering a potential biological mechanism for the cannabis-psychosis association.
The Bigger Picture
The overlap between cannabis-associated methylation and psychosis-related findings in brain tissue suggests that cannabis may partly increase psychosis risk through epigenetic modifications to immune and inflammatory pathways.
What This Study Doesn't Tell Us
Blood methylation may not directly reflect brain methylation. Cross-sectional design cannot determine whether methylation changes preceded or followed cannabis use. The Great Smoky Mountain Study has specific demographic characteristics.
Questions This Raises
- ?Do these methylation changes reverse with cannabis cessation?
- ?Can methylation patterns predict which adolescent cannabis users will develop psychosis?
- ?Are these changes dose-dependent?
Trust & Context
- Key Stat:
- Cannabis-associated methylation in immune cells overlaps with psychosis-related brain findings
- Evidence Grade:
- Large methylome-wide study with novel cell-type-specific analyses, though cross-sectional
- Study Age:
- Published in 2021. Epigenomic studies of cannabis effects are a rapidly emerging field.
- Original Title:
- Methylomic Investigation of Problematic Adolescent Cannabis Use and Its Negative Mental Health Consequences.
- Published In:
- Journal of the American Academy of Child and Adolescent Psychiatry, 60(12), 1524-1532 (2021)
- Authors:
- Clark, Shaunna L(3), Chan, Robin, Zhao, Min(3), Xie, Lin Y, Copeland, William E, Aberg, Karolina A, van den Oord, Edwin J C G
- Database ID:
- RTHC-03065
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Does cannabis change DNA in adolescents?
Not the DNA sequence itself, but this study found cannabis use associated with changes in DNA methylation (epigenetic marks) at 77 sites across different immune cell types. These are potentially reversible modifications that affect gene expression.
How does this relate to psychosis risk?
The methylation changes found in T cells and monocytes overlapped with brain tissue findings from psychosis studies, suggesting cannabis may partly increase psychosis risk through epigenetic modifications to immune pathways.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-03065APA
Clark, Shaunna L; Chan, Robin; Zhao, Min; Xie, Lin Y; Copeland, William E; Aberg, Karolina A; van den Oord, Edwin J C G. (2021). Methylomic Investigation of Problematic Adolescent Cannabis Use and Its Negative Mental Health Consequences.. Journal of the American Academy of Child and Adolescent Psychiatry, 60(12), 1524-1532. https://doi.org/10.1016/j.jaac.2021.02.008
MLA
Clark, Shaunna L, et al. "Methylomic Investigation of Problematic Adolescent Cannabis Use and Its Negative Mental Health Consequences.." Journal of the American Academy of Child and Adolescent Psychiatry, 2021. https://doi.org/10.1016/j.jaac.2021.02.008
RethinkTHC
RethinkTHC Research Database. "Methylomic Investigation of Problematic Adolescent Cannabis ..." RTHC-03065. Retrieved from https://rethinkthc.com/research/clark-2021-methylomic-investigation-of-problematic
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.