Currently, our choice of candidate genes is driven by accumulating evidence from preclinical research on endogenous cannabinoids and clinical research into cannabis-related behaviors. Research into the complex neurochemistry and biochemistry of exogenous cannabinoids is still growing. The identification of novel genes associated with cannabis use disorders will undoubtedly improve our understanding of the biological processes underlying cannabis involvement. With increasing numbers of genetically informative samples and data repositories, such as dbGAP (http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gap), progress in the arena of cannabis-related genomic research is imminent. The challenge will be to integrate the existing and those emerging findings with our current knowledge of the biological systems influencing cannabis involvement. Two key aspects will require attention:
