Oxytocin receptor gene variation rs53576 and alcohol abuse in a longitudinal population representative study.

Background: Oxytocin is an important regulator of social relationships and has been implicated in development of substance use and addiction. We examined the association of a variance in the oxytocin receptor gene (OXTR rs53576 polymorphism) with alcohol use in a population-representative sample, and potential moderation by social functioning.

Methods: The analysis was carried out on the older birth cohort of the longitudinal Estonian Children Personality Behaviour and Health Study (ECPBHS), a cohort of initially 15 years old children (original n=593) recalled at ages 18 and 25. In all data collection waves the participants reported the frequency of consuming alcoholic beverages. Psychiatric interview was carried out at age 25 to assess the lifetime prevalence of substance use disorders. Adverse social interactions with teachers, classmates and family members were self-reported at ages 15 and 18. The minor (A) allele frequency was 0.37.

Results: Males homozygous for the A allele (suggested to be associated with less efficient oxytocinergic functioning) were more frequent alcohol consumers at ages 15 and 18 and also more likely to have had alcohol abuse or addiction by age 25 compared to male G allele carriers. Alcohol use was not associated with the OXTR genotype in females. Both male and female AA homozygotes who had reported less favourable relations with their teachers at age 15 more likely had alcohol use disorder.

Conclusions: OXTR rs53576 polymorphism is associated with alcohol use and prevalence of alcohol use disorders in males, and this may be moderated by inferior interpersonal relationships.