Positron emission tomography imaging of the serotonin transporter in subjects with a history of alcoholism

Background Our purpose was to investigate the serotonin transporter (SERT) in various brain regions of alcoholics using positron emission tomography and C-11 McN5652. Method Thirty-two adult subjects were involved, 17 social drinkers as control subjects and 15 subjects who were abstinent or recovering alcoholics. Concomitant psychiatric diseases were ruled out based on DSM-IV criteria. The majority of subjects were men. Radioligand binding in 11 brain areas was expressed as the total distribution volume (DV), distribution volume of specific binding (DV_spec), and distribution volume ratio (DVR). The cerebellum was used as reference tissue for calculation of DV _spec and DVR. Results In subjects with a history of alcoholism, DV was lower in all brain regions, with significant differences in the midbrain, thalamus, amygdala, pons, cingulate gyrus, frontal cortex, and cerebellum. Additionally, DV_spec was lower in all brain regions, but differences were only significant in the midbrain; DVR was lower in nine regions but the differences did not reach statistical significance. Conclusions These studies demonstrate lower binding of [¹¹C](+)McN5652 to the SERT in the brain of abstinent or recovering alcoholics compared with control subjects. Differences in the radioligand distribution volumes are more significant before than after correction for nonspecific binding of the radioligand.