This study provides a better understanding on the neurobiological mechanisms that may underlie risk of addiction development in carriers of the A118G SNP in <i>OPRM1</i><b>SIGNIFICANCE STATEMENT</b> The pandemic of opioid drug abuse is associated with many socioeconomic burdens.
The OPRM1 A118G single nucleotide polymorphism (SNP rs1799971) gene variant encoding the N40D µ-opioid receptor (MOR) has been associated with dependence on opiates and other drugs of abuse but its mechanism is unknown.