As already mentioned, several studies have shown that AC activity in platelets or lymphocytes of alcohol-dependent individuals is less responsive to various stimulations, such as that by forskolin, compared to non-alcoholdependent individuals.98-103 However, it is not completely clear if these differences are a consequence of alcohol drinking or an indicator of susceptibility to alcohol dependence. Recent studies have shown that platelet AC activity decreases after a period of abstinence from heavy drinking.104 Furthermore, AC activity in alcohol-dependent subjects was lower for those who abstained for a period of time prior to testing.104 Various alcohol-related factors that affect AC activity level may compromise its utility as an endophenotype to study predisposition to alcohol dependence.104
