Aims: The Cloninger type 1 alcoholics are prone to anxiety, and in many cases patients have begun to use alcohol in order to relieve their anxiety. We have previously reported a decrease of the serotonin transporter density in the perigenual anterior cingulate cortex (pACC) in type 1 alcoholics. The 5-HT(1A) receptors are the binding sites for anxiolytic drug buspirone. We aimed to investigate the alteration in the density of 5-HT(1A) receptors, that may also alter the effect of serotonin in the pACC in alcoholics.
Methods: The density of the serotonin receptor 5-HT(1A) among Cloninger type 1 and 2 alcoholics (nine and eight subjects, respectively) and 10 control subjects were determined by postmortem whole-hemisphere autoradiography with WAY-100635.
Results: Substantially sparser 5-HT(1A) (by -31%, P = 0.010) density was observed in the pACC of alcoholic subjects in relation to non-alcoholic comparison subjects. In a secondary analysis for the difference between the alcoholic subtypes and controls, the 5-HT(1A) density was decreased significantly by -32% (P = 0.015) in the upper level of pACC in type 1 alcoholics.
Conclusions: The detected decrease of 5-HT(1A) receptor density on the pACC suggests further that the serotoninergic system is defected in the so-called affect region, especially in the type 1 alcoholics.