Abstract Abnormal -adrenergic receptor (AR) density in the brains of suicide victims has been reported, although results of studies are inconsistent. Ethanol modifies AR-mediated signal transduction. Moreover abnormal AR function has been implicated in alcoholism. AR antagonists, which were used as ligands in previous AR binding studies, also bind to 5-HT1B/1D receptors; hence, their estimates of AR density are confounded by binding to 5-HT1B/1D receptors. More importantly, previous studies did not examine AR agonist affinity or coupling efficiency to Gs protein. We investigated agonist affinity and coupling efficiency of AR to Gs protein in the brains of ten suicide victims, six subjects with alcoholism, and eight controls. There were no differences in AR density in either the frontal cortex or hippocampus of suicide victims or alcoholic subjects compared to controls. Preliminary results indicate AR supercoupling in suicide victims in both brain regions and uncoupling in alcoholic subjects in the frontal cortex. These results are discussed in view of the existing literature on the role of AR in suicide and alcoholism and the mechanism of action of antidepressants.