Dopamine transporter in alcoholism : a SPET study

Abstract

A large body of animal studies indicates that reinforcement from alcohol is associated with dopaminergic neurotransmission in the mesocorticolimbic pathway. However, as most psychiatric phenomena cannot be studied with animals, human studies are needed. Furthermore, because of the fluctuating nature of phenomena regarding the status of abuse and withdrawal, repeated observations of the same study subjects under different situations can elucidate a variety of pathophysiological mechanisms.

In this study 42 alcoholics were monitored during withdrawal and 30 alcoholics after four weeks of abstinence. ¹²³β-CIT SPET was used as a method for the semi quantification of their striatal dopamine transporter (DAT) densities reflecting the function and structure of the dopaminergic system.

DAT density was markedly lower during withdrawal among alcoholics as compared to control subjects, but it elevated during abstinence to the level of healthy volunteers. This increases in DAT density during withdrawal and afterwards correlated with the depression scores of alcoholics. DAT density correlated with the Novelty Seeking (NS) personality trait, especially among abstinent alcoholics. After four weeks of controlled abstinence alcoholics with an A1 allele of dopamine receptor D2 were found to have higher DAT densities than alcoholics without it.

The results indicate that striatal DAT density is associated with mood, personality, A1 genotype and the length of the abstinence period after heavy alcohol drinking.