The Interactive Nature of Cannabis and Schizophrenia Risk Genes

Cannabis abuse and the development of schizophrenia appear to be linked, although the exact nature of this relationship is unclear. There is substantial epidemiological evidence showing that cannabis increases the risk of schizophrenia. However, the majority of cannabis abusers will never experience a psychotic episode. It has been hypothesized that schizophrenia patients carrying particular risk genes might be more susceptible to the psychosis-inducing effects of cannabis than other patients and healthy test subjects. In the last decade, genetic mouse model research has guided human studies on which genes to focus. Furthermore, human linkage and association studies have identified novel genetic variants, which can be modeled in mice, in an effort to delineate molecular, cellular, and neurobiological mechanisms involved in gene-cannabis interactions. Here, we will review human and mouse literature on the interactive effects of cannabis, and the two risk genes neuregulin 1 (NRG1) and catechol-O-methyltransferase (COMT).