Svob Strac D, et al. – In this first-in-kind study, researchers investigated the association of platelet serotonin (5-HT) and HTR1B gene with the onset of alcohol abuse in alcohol-dependent individuals. Study participants included 613 alcohol-dependent study participants subdivided based on early (before age 25)/late (after age 25) alcohol abuse, among whom determination of platelet 5-HT concentration and genotyping of rs13212041 HTR1B gene polymorphism were performed. According to findings, alcohol-dependent individuals with CC genotype were more common in the early-onset alcohol abuse group vs T allele carriers. In addition to the HTR1B genotype, age and sex were important variables associated with the onset of alcohol abuse, but not platelet 5-HT. The platelet 5-HT concentration did not differ significantly between patients with early and late alcohol abuse or those with different genotypes of HTR1B. In this analysis, the potential involvement of 5-HT1B receptors in the onset of alcohol abuse and the development of alcohol dependence was supported. Researchers also highlighted the significance of controlling the smoking status as one of the important confounding factors influencing the 5-HT platelet concentration.