In the three cluster solution, the most common cluster was a Type A/I cluster (N=114, 56%), and the second most common was a Type B/II (N=70, 35%). The Type B/II cluster, as compared to the Type A/I cluster, was characterized by a earlier age of onset of use (mean 11.5 compared to 13.9 years), more conduct and adult antisocial behaviors, and more cannabis dependence and withdrawal symptoms. The third cluster, called “Cluster 3” in this analysis, was the least common (N=18, 9%); it was not different from the Type A/I cluster on any variable except age of onset of use (mean 19.9 compared to 13.9 years). The Type B/II cluster, as compared to Cluster 3, was characterized by earlier age of onset of use (mean 11.5 compared to 19.4 years), more conduct and adult antisocial behaviors, and more cannabis dependence symptoms, but not more withdrawal symptoms. Numbers of independent anxiety and affective disorders did not differ in any pairwise cluster comparison.
