Association of the Neuronal Cell Adhesion Molecule (NrCAM) Gene Variants with Personality Traits and Addictive Symptoms in Methamphetamine Use Disorder

OBJECTIVE 1) To investigate the relationship between NrCAM polymorphisms and methamphetamine abuse in an ethnically homogenous Korean population. 2) To further support our findings by investigating the association among NrCAM gene variants, certain personality traits, and addictive symptoms of methamphetamine abusers. METHODS Thirty-seven male methamphetamine abusers (age=43.3±7.8) and30 non-users (16 men, 14 women; age=59.8±10.4) were recruited. Ten single nucleotide polymorphisms (SNPs) in the NrCAM gene were assayed to compare genotype distributions between the 2 groups. Personality characteristics were measured using the Temperament and Character Inventory (TCI) and the NEO Personality Inventory, Revised (NEO PI-R). Addictive symptoms were assessed using the Diagnostic Interview for Genetic Studies (DIGS) and reviews of the subject's medical records. RESULTS Among the 10 SNPs in the NrCAM gene, the frequency of the TA genotype at rs1990162 was significantly lower in methamphetamine abusers compared to non-users (p=0.042). In the 3 NrCAM gene SNPs (rs381318, rs2072546, and rs6954366), the distribution of genotypes and alleles were significantly associated with some traits in the TCI and NEO PI-R. Genotypes and alleles at 5 gene SNPs (rs2142325, rs381318, rs1269621, rs1269634, and rs1990162) were associated with certain addictive symptom dimensions in the patients. CONCLUSION These findings support the idea that NrCAM is associated with genetic susceptibility of methamphetamine abuse and is also associated with certain personality characteristics that may increase disturbed addictive behavior.