Objective: This study examined the genetic association between variation in the cannabinoid receptor 1 (CNR1) gene and cannabis dependence symptoms.
Method: Adolescent and young adult subjects were recruited from three settings: a treatment program for youth with substance use disorders, the criminal justice system, and the community. A case-control sample consisted of 224 cases who endorsed at least one dependence symptom and 108 controls who tried cannabis but endorsed no symptoms. A family-based sample of 219 families was also analyzed.
Results: Case-control analysis identified a nominal association between SNP rs1049353 and having one or more cannabis dependence symptoms (p=.029), but the association did not hold up in a combined sample. Family-based analysis found a trend for the same SNP (p=.07). We did not replicate a previous report that SNP rs806380 was associated with the development of cannabis dependence.
Conclusion: These results provide inconclusive evidence of association between rs1049353/rs806380 and the development of cannabis dependence, and underscore the importance of replicating results of genetic association studies. Additional family-based studies are needed to clarify the role of the CNR1 gene, and its various SNPs, in the development of cannabis use disorders.