Aurora, CO: Twins who reside in adult-use marijuana states are less likely to report experiencing negative consequences from drinking alcohol as compared to their co-twins who live in jurisdictions where cannabis remains illegal, according to data published in the American Journal of Drug and Alcohol Abuse.
A team of researchers affiliated with the University of Colorado and the University of Minnesota assessed the relationship between adult-use cannabis legalization and the use of marijuana and alcohol in a cohort consisting of twins. One twin resided in a jurisdiction where adult-use cannabis sales are legally permitted, while the other lived in a state where they are prohibited.
Investigators reported that although twins residing in legal states consumed alcohol at rates similar to their co-twins, they were less likely to report ill effects from drinking.
“Twins living in a state with RCL [recreational cannabis laws] reported fewer negative consequences from alcohol use than their co-twin living in a non-RCL state,” they determined. “These results support the hypothesis that more liberal cannabis policies may result in fewer negative consequences from alcohol use.”
Researchers reported higher levels of cannabis use among twins residing in legal states, a finding that is consistent with prior data. However, twins residing in legal states were no more likely than their co-twins to report experiencing negative consequences as a result of their marijuana use. Twins in legal states did not use tobacco or other controlled substances at higher rates than their co-twins.
The findings are similar to those of a study published earlier this year that reported lower levels of alcohol use disorder among twins residing in states where cannabis is legal.
Full text of the study, “Evaluating substance use outcomes of recreational cannabis legalization using a unique co-twin control design,” appears in the American Journal of Drug and Alcohol Abuse.