[Genetic polymorphisms commonly associated with sensitivity to various addictive substances].

Opioids, such as morphine and fentanyl, are widely used as effective analgesics for the treatment of acute and chronic pain. In addition, the opioid system has a key role in the rewarding effects of morphine, ethanol, cocaine and various other drugs. The authors have focused on G-protein-activated inwardly rectifying potassium (GIRK) channel subunits, GIRK2 and GIRK3, which are important molecules in opioid transmission, and found that the SNPs within the GIRK2 and GIRK3 gene region were significantly associated with postoperative analgesic requirements, one of which was also associated with vulnerability to methamphetamine (METH) dependence. Further, by conducting a multistage genome-wide association study (GWAS) in healthy subjects, the authors found that the rs2952768 single-nucleotide polymorphism (SNP) was strongly associated with the requirements for postoperative opioid analgesics after painful cosmetic surgery and consistent results were obtained in patients who underwent abdominal surgery. In addition, the SNP also showed significant association with vulnerability to severe drug dependence in patients with METH dependence, alcohol dependence, and eating disorders and a lower 'Reward Dependence' score on a personality questionnaire in healthy subjects. These outcomes provide valuable information for the personalized treatment of pain and drug dependence.