The impact of adverse life events and the serotonin transporter gene promoter polymorphism on the development of eating disorder symptoms

Adverse life events have been shown to predict weight fluctuations and dietary restraint, as well as eating disorders during adolescence or early adulthood. Since the s-allele carriers of the 5-HTT gene-linked polymorphic region (5-HTTLPR) are biologically more reactive to stress related stimuli, we aimed to explore whether the eating disturbances are predicted by environmental stressors and moderated by the 5-HTTLPR genotype. The sample was based on the younger cohort of the Estonian Children Personality, Behaviour and Health Study and included those participating in its second and third wave. The history of stressful life events was self-reported at age 15. Data on eating behaviour and attitudes, anxiety, impulsivity and depressiveness were collected at age 18. The effect of the adverse life events on binge eating and on drive for thinness was found to be moderated by the 5-HTTLPR. Adolescent girls who at age 15 had reported a history of frequent adverse life events had elevated scores in EDI-2 Bulimia subscale at age 18 if they were carrying the s-allele. The effect of the s-allele on binge eating was even more pronounced when solely the experience of sexual abuse was considered. The interaction effect of the 5-HTTLPR and the past sexual abuse was also observed on drive for thinness. These data give further support to the idea that adverse life events in childhood may heighten susceptibility to serotonergic dysregulation following stress, and suggest that in individuals vulnerable to eating disorders this may result in disturbed eating behaviours.