Dimensions of the subjective marijuana experience.

A Drug History Questionnaire and a Marihuana Effects Questionnaire were completed by 91 male volunteers who were experienced marijuana smokers. A factor analysis was performed on the frequency of occurrence data for the Marihuana Effects Questionnaire. The resultant factors were similar to those reported previously in the literature supporting the existence of a stable, verbally definable marijuana experience. In comparison to the drug history variables of marijuana smokers in the late 1960s, our population showed increased multiple drug use, an earlier age of introduction to cannabis, and heavier use of cannabis. An analysis of the interaction of drug history variables with experienced marijuana effects suggested that the more frequently one uses cannabis, the less pronounced the experienced effects tend to be.