Mu opioid receptor gene variant modulates subjective response to smoked cannabis.

The mu-opioid receptor (MOR) mediates the rewarding properties of many psychoactive drugs and is an important target in the treatment of addictions. Functional interactions between the opioid and endocannabinoid systems are established and have been hypothesized to contribute to the effects of cannabis. We investigated associations between three single nucleotide polymorphisms in the MOR gene (rs1799971, rs2281617, and rs510769) and subjective responses to smoked cannabis.