The additive effect of neurotransmitter genes in pathological gambling

As access to gambling increases there is a corresponding increase in the fr equency of addiction to gambling, known as pathological gambling. Studies h ave shown that a number of different neuro transmitters are affected in pat hological gamblers and that genetic factors play a role. Polymorphisms at 3 1 different genes involved in dopamine, serotonin, norepinephrine, GABA and neurotransmitters were genotyped in 139 pathological gamblers and 139 age, race, and sex-matched controls. Multivariate regression analysis was used with the presence or absence of pathological gambling as the dependent vari able, and the 31 coded genes as the independent variables. Fifteen genes we re included in the regression equation. The most significant were the DRD2, DRD4, DAT1, TPH, ADRA2C, NMDA1, and PSI genes. The r(2) or fraction of the variance was less than 0.02 for most genes. Dopamine, serotonin, and norep inephrine genes contributed approximately equally to the risk for pathologi cal gambling. These results indicate that genes influencing a range of brai n functions play an additive role as risk factors for pathological gambling . Multi-gene profiles in specific individuals may be of assistance in choos ing the appropriate treatment.