Alcohol dependence, family history, and D2 dopamine receptor function as neuroendocrinologically assessed with...

Fifteen alcohol dependent men with an alcohol dependent first degree relative (i.e. family history positive or FHP), 15 well matched alcohol dependent men without a family history for alcohol dependence (i.e. family history negative or FHN), and 15 healthy controls (CONTR) participated in this study. The three groups were compared according to their postsynaptic D2 dopamine receptor function as assessed by growth hormone release after stimulation with the dopamine receptor agonist apomorphine. Statistical evaluation was done by planned comparisons within a one-way ANOVA. Alcohol dependent subjects significantly differed from CONTRs as long as family history was not taken into account (t(42) = 2.38; P = 0.022*). When differentiating according to family history, both FHPs and FHNs maintained a blunted growth hormone response. However, the difference between FHNs and CONTRs, though present, dropped out of statistical significance (t(42) = 1.65; P = 0.105); at the same time, the difference between FHPs and CONTRs became slightly stronger (t(42) = 2.47; p = 0.017*). In conclusion, our data give neuroendocrinological support to the assumption that a reduced D2 dopamine receptor function in alcohol dependent men is not only a state marker of residual heavy drinking but also a genetically determined trait marker.