The results of this study suggest that, in general, a dichotomous typology similar to Babor’s Types A/B (Babor et al. 1992) and Cloninger’s Types I/II (Cloninger et al. 1981) for alcohol dependence characterizes cannabis dependence in this Indian community with the exception of an infrequent late onset cluster that may represent a temporal cohort effect. In this sample, the Type B/II cluster (in comparison to the Type A/I cluster) for cannabis dependence had an earlier age of onset of use, more childhood conduct and adult antisocial behaviors, and more cannabis dependence and withdrawal symptoms. Numbers of independent anxiety and affective disorders did not differ between the clusters. The Type B/II cluster was found to be heritable (h2 = 0.44, S.E. = 0.18, p<0.01), while the Type A/I and Cluster 3 were not found to be heritable.
