Parental divorce and disordered eating: An investigation of a gene-environment interaction

Objective: Previous research demonstrates an association between parental divorce and disordered eating that has traditionally been conceptualized as environmental in nature. However, it is possible that a gene-environment interaction may drive this relationship, whereby parental divorce serves as an environmental "trigger" for pre-existing genetic susceptibilities to disordered eating. This study examined this possibility by investigating whether the heritability of disordered eating is significantly higher in children living in divorced versus intact families. Methods: Participants included 1,723 adolescent and adult twins (mean age = 18.27) from the Michigan State University Twin Registry and the Minnesota Twin Family Study. Disordered eating was measured with the Minnesota Eating Behavior Subscale (MEBS). Univariate, twin constraint models were used to compare the heritability of disordered eating in divorced versus intact families. Results: A gene-environment interaction was not observed for most measures of disordered eating. However, a gene-environment interaction was suggested for body dissatisfaction, as the heritability of body dissatisfaction was higher in twins of divorced versus intact families. Discussion: Although gene-environment interactions do not appear to be important for relationships between divorce and most forms of disordered eating, the presence of these effects for body dissatisfaction requires further study. Future investigations should replicate our results and begin to identify the factors underlying the unique gene-environment relationships between divorce and body dissatisfaction.