Lower [3H]Citalopram Binding in Brain Areas Related to Social Cognition in Alcoholics

Aims: In the present study, putative alterations in the serotonin transporter density were evaluated in anterior and posterior insula, posterior cingulate cortex, dorsolateral and dorsomedial prefrontal cortex, hippocampus, parahippocampal gyrus and dorsal raphe nucleus in Cloninger type 1 (n = 9) and type 2 (n = 8) alcoholics and non-alcoholic controls (n = 10). Methods: Human whole-hemisphere autoradiography was used to measure [H-3]citalopram binding to serotonin transporters in eight brain areas in all post-mortem brains. Results: Significant differences were observed in the mean [H-3]citalopram binding between the study groups, with antisocial type 2 alcoholics showing the lowest binding. Differences between the study groups were prominent in the posterior insula and posterior cingulate cortex, where both alcoholic groups had low [H-3]citalopram binding, and in the parahippocampal gyrus where only antisocial type 2 alcoholics had low [H-3]citalopram binding when compared with non-alcoholic controls. Conclusion: Although these data are preliminary, and from relatively small diagnostic groups, these results show that alcoholics may have lower serotonergic tone in the brain, thus decreasing social cognition and increasing alcohol-cue reactivity.