Alcohol and drug use in groups of cannabis users: Results from a survey on drug use in the Swedish general population

Background and Objectives Although cannabis is well studied in the scientific literature, relatively little is known about the relationship between the frequency of cannabis use and the use of alcohol and other drugs. The aim of this study was to identify differences between frequent and occasional cannabis users with respect to the use of other illicit drugs, hazardous alcohol use, and unauthorized use of prescription drugs. Methods Results from a questionnaire on drug use taken by 22,095 individuals in the Swedish general population were analyzed with a logistic regression model. Active cannabis use was defined as having used cannabis in the past 12 months. Use of cannabis two-to-three times per week or more was classified as frequent use. Results Cannabis users were more likely to report hazardous alcohol use, use of other illicit drugs, and unauthorized use of prescription drugs than were non-users. Within the group of active cannabis users, frequent cannabis use, compared to occasional use, was associated with the use of other illicit drugs and negatively associated with hazardous alcohol use. Discussion and Conclusions The association between cannabis use and hazardous alcohol use, use of other illicit drugs, and unauthorized use of prescription drugs was expected. However, the negative association between frequent cannabis use and hazardous alcohol use among active cannabis users was surprising. This indicates that frequent cannabis users may differ from more occasional users in clinical needs. Scientific Significance These results show a previously unknown characteristic of the association between frequency of cannabis use and hazardous alcohol use in the general population. (Am J Addict 2014;23:272-279)