Serotonin transporter gene promoter polymorphism affects the severity of binge eating in general population

ObjectiveThe s-allele of the 5-HTTLPR has been suggested to lead to the development of less efficient and less flexible 5-HT system and has been associated to different forms of psychopathology. It has also been shown that alterations in serotonergic activity contribute to the pathophysiology of binge eating but it is not clear which changes in 5-HT function observed in eating disorder patients represent trait vs state effect. We investigated the association between the 5-HTTLPR and binge eating in a population-representative sample of women, and tested whether the 5-HTTLPR genotype influences the severity of binge eating.MethodsThe sample was based on women participating in the third wave of the Estonian Children Personality, Behaviour and Health Study. EDI-2 subscales – drive for thinness and bulimia – were used to assess eating behaviour and attitudes. Barratt Impulsiveness Scale (BIS-11) and State and Trait Anxiety Inventory (STAI) were used to measure impulsivity and anxiety. Participants were genotyped for the 5-HTTLPR.ResultsThere was no 5-HTTLPR genotype effect on binge eating even after the covarying effect of impulsivity and anxiety was controlled for. However, women prone to binge eating and carrying the s-allele showed significantly higher levels of bulimia scores, and among them, women with s/s genotype had also higher levels of state anxiety and tendency for higher impulsivity.ConclusionsWhile the 5-HTTLPR genotype does not predict symptoms of eating disorder in general population, the s-allele, and especially the s/s genotype increases the risk for affective instability and symptom severity.