day (Ma et al. 2003). There have been some findings in genome scans for cannabis dependence and other drug use related phenotypes on chromosome 19. A region has been identified on chromosome 19 at 17 cM for early-onset cannabis use in a study of 2314 Australian families (Agrawal et al. 2008). Closer to the region identified in the present study were the findings from the COGA study for a genome-wide screen for genes influencing conduct disorder where a region was identified on chromosome 19 at 35 cM.
