Dopamine and Dependence in Families with Alcoholism

Various studies suggest that striatal levels of dopamine D₂ receptors are low in alcoholics. These researchers hypothesized that high D₂ receptor levels might protect against alcoholism in individuals with strong family histories of alcohol dependence. They studied 15 nonalcoholic individuals with positive family histories (FP group; alcoholism in the father and two other relatives; mean age, 24; one woman) and 16 nonalcoholic controls with negative family histories (FN group; mean age, 26; two women).

Because alcohol could alter D₂ mechanisms, the researchers excluded alcohol-dependent subjects, who were generally past the time of highest risk (about 83% of alcohol addiction occurs by age 24). The investigators used PET scans to determine D…