Cocaine and amphetamine regulated transcript (CART) gene in the comorbidity of schizophrenia with alcohol use disorders and nicotine dependence.

Studies have shown a genetic susceptibility to develop schizophrenia, alcohol use disorders and nicotine dependence. Brain areas related to reward and reinforcement show high expression of the cocaine and amphetamine regulated transcript (CART). Nicotine and alcohol are also able to modulate CART expression in the hypothalamic areas. In this study, we evaluated whether CART variants would influence the predisposition of schizophrenia subjects to alcohol use disorders and nicotine dependence. Clinical and genetic data were obtained from 190 unrelated Caucasian schizophrenia subjects collected at the Centre for Addiction and Mental Health. We found no association of CART variants with alcohol use disorders or nicotine dependence. We found a trend for allelic association of rs11575893 with the heaviness of smoking behaviour (p=0.057). Our results indicate that genetic variants in the CART gene may not play a major role in the vulnerability of schizophrenia subjects to concurrent alcohol use disorders and nicotine dependence. Additional association studies in independent samples can evaluate whether CART gene is playing a role in the schizophrenia comorbidity with alcohol use disorders and nicotine dependence.