Subsensitive alpha-2-adrenoceptor function in male alcohol-dependent individuals during 6 months of abstinence

Postsynaptic alpha-2-receptor function, as assessed by growth hormone (GH) response to clonidine (CLON), has been shown to be downregulated in patients investigated in acute but also in late withdrawal after heavy alcohol intake. The results are however sometimes conflicting. The question whether this changed receptor function is a trait or state marker is not fully investigated so far. A total of seven male patients with alcohol dependence according to DSM-IV were assessed for the postsynaptic alpha-2-receptor function with the CLON/GH test (2.0 microg/kg body weight; i.v.) starting immediately after a period of heavy drinking. Neuroendocrine tests were repeated after 7 days, 2 and 6 months. A total of six healthy males were used as controls. The maximum GH responses to CLON were significantly lower on all four test occasions in the patient group as compared to the controls. Furthermore, in the patient group all neuroendocrine test results showed blunted GH responses to CLON. Thus, patients with downregulated alpha-2-receptor function during acute withdrawal after heavy alcohol intake showed similar subsensitive receptor function abnormality after a prolonged period of abstinence. The findings in this study indicate that alcohol dependent individuals have a persistent subsensitive alpha-2-adrenoceptor function which may constitute a trait factor for alcohol dependence.