Chronic Cannabis Use in Teens Linked to DNA Changes That May Affect Verbal Memory

In a small study of 18 adolescents, chronic cannabis use was associated with changes at six DNA methylation sites that statistically mediated the link between cannabis use and lower verbal learning scores.

Wiedmann, Melina et al.·Translational psychiatry·2022·Preliminary EvidenceObservational
RTHC-04302ObservationalPreliminary Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Observational
Evidence
Preliminary Evidence
Sample
N=18

What This Study Found

Six CpG methylation sites showed reduced methylation associated with the extent of chronic cannabis use. All six sites mediated the relationship between cannabis use and impaired verbal free recall performance. The affected genes had been previously linked to neurodegeneration, hippocampus-dependent learning, and neurogenesis.

Key Numbers

18 adolescents total (9 cannabis users, 9 controls); 6 CpG sites with reduced methylation; all 6 mediated the effect on verbal learning free recall; cannabis users abstinent at least 24 hours before testing

How They Did This

Exploratory whole-genome methylation study of 18 adolescents (9 psychiatric outpatients with chronic cannabis use, 9 matched controls without). Groups matched for age, gender, and psychiatric disorders. Cannabis users were abstinent at least 24 hours before cognitive testing. Blood samples analyzed for CpG methylation via principal component analysis and mediation analyses.

Why This Research Matters

This is among the first studies to look at whether DNA methylation changes might explain how cannabis affects memory in young people. If confirmed, it would suggest cannabis does not just temporarily impair cognition but may alter gene expression in ways relevant to brain function.

The Bigger Picture

Epigenetic changes represent a potential biological mechanism connecting cannabis use to cognitive effects. If replicated in larger samples, these methylation markers could become useful biomarkers for cannabis-related cognitive risk.

What This Study Doesn't Tell Us

Very small sample of 18 participants severely limits statistical power and generalizability. Cannot determine whether methylation changes are caused by cannabis use or reflect pre-existing differences. Peripheral blood methylation may not reflect brain methylation patterns.

Questions This Raises

  • ?Do these methylation changes reverse with sustained abstinence?
  • ?Are the same patterns present in adult cannabis users?
  • ?Would brain tissue show similar methylation changes at these sites?

Trust & Context

Key Stat:
6 DNA methylation sites identified
Evidence Grade:
Exploratory study with very small sample size (n=18); findings need replication in larger cohorts
Study Age:
2022 study
Original Title:
DNA methylation changes associated with cannabis use and verbal learning performance in adolescents: an exploratory whole genome methylation study.
Published In:
Translational psychiatry, 12(1), 317 (2022)
Database ID:
RTHC-04302

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Watches what happens naturally without intervening.

What do these levels mean? →

Frequently Asked Questions

Does cannabis permanently change DNA in teenagers?

This study found changes in DNA methylation, not DNA sequence. Methylation is a chemical modification that affects gene expression and may be reversible, though this study did not test reversibility.

How reliable are findings from 18 participants?

Findings from such a small sample are preliminary and exploratory. The authors themselves note that results must be carefully interpreted and replication studies are needed.

Read More on RethinkTHC

Cite This Study

RTHC-04302·https://rethinkthc.com/research/RTHC-04302

APA

Wiedmann, Melina; Kuitunen-Paul, Sören; Basedow, Lukas Andreas; Wolff, Max; DiDonato, Nataliya; Franzen, Julia; Wagner, Wolfgang; Roessner, Veit; Golub, Yulia. (2022). DNA methylation changes associated with cannabis use and verbal learning performance in adolescents: an exploratory whole genome methylation study.. Translational psychiatry, 12(1), 317. https://doi.org/10.1038/s41398-022-02025-6

MLA

Wiedmann, Melina, et al. "DNA methylation changes associated with cannabis use and verbal learning performance in adolescents: an exploratory whole genome methylation study.." Translational psychiatry, 2022. https://doi.org/10.1038/s41398-022-02025-6

RethinkTHC

RethinkTHC Research Database. "DNA methylation changes associated with cannabis use and ver..." RTHC-04302. Retrieved from https://rethinkthc.com/research/wiedmann-2022-dna-methylation-changes-associated

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.