Endocannabinoid gene interactions were linked to alcohol use disorder risk in European teens

Gene-gene interactions among endocannabinoid system genes (CNR1, MGLL, DAGLA) were associated with alcohol use disorder risk in European adolescents, with partial replication in a Canadian cohort.

Elkrief, Laurent et al.·Frontiers in psychiatry·2021·Preliminary EvidenceLongitudinal Cohort
RTHC-03115Longitudinal CohortPreliminary Evidence2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Longitudinal Cohort
Evidence
Preliminary Evidence
Sample
N=2,051

What This Study Found

Two SNPs were significantly associated with positive AUDIT screens after correction: rs9353525 in CNR1 (OR=0.73) and rs507961 in MGLL (OR=0.78). A three-SNP interaction model involving MGLL, DAGLA, and CNR1 predicted case-control status after correcting for covariables. This interaction showed a trend toward replication in the Canadian SYS cohort (BETA=0.501, p=0.06).

Key Numbers

IMAGEN: n=2,051 European adolescents; SYS: n=772 Canadian adolescents; rs9353525 (CNR1) OR=0.73, p=0.042; rs507961 (MGLL) OR=0.78, p=0.043; 3-SNP interaction model p=0.006; replication trend BETA=0.501, p=0.06

How They Did This

Set-based gene testing and SNP-level analysis in 2,051 European adolescents (14-18) from the IMAGEN study, with replication attempted in 772 Canadian adolescents from the Saguenay Youth Study. AUDIT score >7 defined case status. Generalized multifactor dimensionality reduction analyzed gene-gene interactions.

Why This Research Matters

The endocannabinoid system is primarily associated with cannabis effects, but these findings suggest it also plays a role in alcohol use disorder risk, potentially through shared reward pathway modulation. This has implications for understanding cross-substance vulnerability.

The Bigger Picture

Finding that endocannabinoid genes contribute to alcohol disorder risk through gene-gene interactions suggests the endocannabinoid system may be a common vulnerability pathway for multiple substance use disorders, not just cannabis-related ones.

What This Study Doesn't Tell Us

Preliminary findings with modest effect sizes. Replication in the Canadian cohort only reached trend-level significance (p=0.06). AUDIT screening is not equivalent to clinical diagnosis. European-ancestry cohorts limit generalizability.

Questions This Raises

  • ?Would these genetic interactions also predict cannabis use disorder or polysubstance use?
  • ?Could endocannabinoid system-targeted medications help prevent alcohol use disorder in genetically vulnerable adolescents?

Trust & Context

Key Stat:
3-SNP interaction across CNR1, MGLL, and DAGLA predicted alcohol disorder risk
Evidence Grade:
Well-designed genetic study with two cohorts, but modest effect sizes and only trend-level replication make findings preliminary.
Study Age:
Published in 2021.
Original Title:
Endocannabinoid Gene × Gene Interaction Association to Alcohol Use Disorder in Two Adolescent Cohorts.
Published In:
Frontiers in psychiatry, 12, 645746 (2021)
Database ID:
RTHC-03115

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Follows a group of people over time to track how outcomes develop.

What do these levels mean? →

Frequently Asked Questions

What are endocannabinoid genes?

These are genes that code for components of the endocannabinoid system, including cannabinoid receptors (CNR1) and enzymes that produce or break down endocannabinoids (DAGLA, MGLL). Variants in these genes can affect how the system functions.

Why would cannabis-related genes affect alcohol risk?

The endocannabinoid system modulates reward circuitry in the brain that responds to multiple substances, not just cannabis. Genetic variation in this system could alter reward sensitivity broadly, affecting vulnerability to alcohol and potentially other substances.

Read More on RethinkTHC

Cite This Study

RTHC-03115·https://rethinkthc.com/research/RTHC-03115

APA

Elkrief, Laurent; Spinney, Sean; Vosberg, Daniel E; Banaschewski, Tobias; Bokde, Arun L W; Quinlan, Erin Burke; Desrivières, Sylvane; Flor, Herta; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Brühl, Rüdiger; Martinot, Jean-Luc; Paillère Martinot, Marie-Laure; Nees, Frauke; Papadopoulos Orfanos, Dimitri; Poustka, Luise; Hohmann, Sarah; Millenet, Sabina; Fröhner, Juliane H; Smolka, Michael N; Walter, Henrik; Whelan, Robert; Schumann, Gunter; Pausova, Zdenka; Paus, Tomáš; Huguet, Guillaume; Conrod, Patricia. (2021). Endocannabinoid Gene × Gene Interaction Association to Alcohol Use Disorder in Two Adolescent Cohorts.. Frontiers in psychiatry, 12, 645746. https://doi.org/10.3389/fpsyt.2021.645746

MLA

Elkrief, Laurent, et al. "Endocannabinoid Gene × Gene Interaction Association to Alcohol Use Disorder in Two Adolescent Cohorts.." Frontiers in psychiatry, 2021. https://doi.org/10.3389/fpsyt.2021.645746

RethinkTHC

RethinkTHC Research Database. "Endocannabinoid Gene × Gene Interaction Association to Alcoh..." RTHC-03115. Retrieved from https://rethinkthc.com/research/elkrief-2021-endocannabinoid-gene-gene-interaction

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.