Molecular-genetic correlates of self-harming behaviors in eating-disordered women: Findings from a combined Canadian-German sample

Across populations, findings suggest that rates of self-mutilation, suicidal acts, and other self-harming behaviors (SHBs) may be influenced by polymorphisms that code for activity of the serotonin transporter (e.g., 5HTTLPR) and the enzyme, monoamine oxidase A (e.g., MAOAuVNTR). SHBs being common in patients with Eating Disorders (EDs), we evaluated (in a large sample of eating-disordered women) relationships between triallelic 5HTTLPR and MAOAuVNTR variants, on the one hand, and SHBs, on the other. We had 399 eating-disordered women report on eating symptoms and lifetime history of SHBs, and provide blood samples for genotyping. Individuals carrying high-function MAOAuVNTR alleles reported a history of SHBs about twice as often as did carriers of low-function alleles. We obtained no comparable main effect of 5HTTLPR, or MAOAuVNTR x 5HTTLPR interaction effect. Genetic variations did not predict severity of eating symptoms. As in other populations, our findings link the MAOAuVNTR high-function alleles with increased risk of self-directed harm in bulimic females. We discuss theoretical and clinical ramifications of our results.