Alpha-1- and 2-adrenoceptor subsensitivity in siblings of opioid addicts with personality disorders and depression.

Noradrenergic receptor sensitivity of 16 healthy male siblings of heroin addicts and of 8 age and sex-matched controls was examined by administering a clonidine stimulation test and by measuring the resulting growth hormone (GH) (alpha-2-adrenoceptors) and beta-endorphin (beta-endorphin) (alpha-1-adrenoceptors) responses. Siblings were divided into two groups: A = siblings of heroin addicts with personality disorders and high aggressivity and B = siblings of heroin addicts without mental disorders. The GH and beta-endorphin responses to clonidine were blunted in group A subjects compared with controls and normal in group B.