There were several areas of the genome that were reported previously as being linked to cannabis use that were not identified in the current linkage scan for cannabis dependence phenotypes in the UCSF Family study. For instance, Agrawal and colleagues [2008d] conducted a linkage scan in a sample from the COGA study for six DSM-IV cannabis dependence criteria considered as a continuous variable (0-6) and found a maximum LOD score of 1.9 at 95 cM on chromosome 14. A site on chromosome 14 at 122 cM was also found for a severe cannabis subtype generated by a cluster analysis in an American Indian community [Ehlers et al., 2009]. This region on chromosome 14 was also identified previously in a genome-wide linkage analysis for ASPD/CD in that American Indian community [Ehlers et al., 2008]. Two areas of the genome were also identified in that American Indian community study with LOD scores that provide evidence for linkage for a severe cannabis use/antisocial subtype on chromosome 16 (@139 cM, LOD score = 4.4), and on chromosome 19 (@74 cM, LOD score = 6.4)
