The genetics of addiction: alcohol-dependence and D3 dopamine receptor gene

Alcohol-dependence is a complex phenotype, with behavioral, psychological, pharmacological, medical and social dimensions. Aggregation studies, adopti on and twin researches have demonstrated that the vulnerability to alcohol- dependence is at least in part linked to genetic factors, the genetic vulne rability to alcoholism being mainly not substance-specific. There are numer ous candidate genes, but the D3 dopamine receptor is specifically located i n the limbic area, and in particular in the nucleus accumbens, which are in volved in reward and reinforcement behavior. Furthermore, a previous collab orative study showed that homozygosity for the Ball DRD3 locus was more fre quently observed in opiate dependent patients with high sensation seeking s cores. In this study, we analyzed the distribution of Ball DRD3 polymorphis m in a new sample of 131 French male alcohol ic-patients (DSM III-R criteri a) and 68 healthy controls matched for sex and origins. Although we replica ted the higher sensation seeking score in alcohol-dependent patients with c omorbid dependence, we found no significant difference in the DRD3 gene pol ymorphism between controls and alcoholic patients, regardless of sensation seeking score, addictive or psychiatric comorbidity, alcoholism typology, a nd clinical specificities of alcoholism. There is good evidence that gene c oding for the dopamine receptor D3 does not play a major role in the geneti c vulnerability to alcoholism. (C) 2001 Editions scientifiques et medicales Elsevier SAS.