Two hundred and two individuals with lifetime DSM-III-R cannabis dependence provided the information on variables associated with cannabis use and cannabis dependence used to generate clusters. Two, 3, and 4 cluster solutions were considered. The three-cluster solution showed the best separation of the data as evidenced by significant separation of a larger number of variables than was seen in the two and four cluster solutions. Therefore the three cluster solution was used in subsequent analyses including estimates of heritability and linkage.
