Anorexia nervosa polygenic risk, beyond diagnoses: relationship with adolescent disordered eating and behaviors in an Australian female twin population

Madeleine Curtis; Lucia Colodro-Conde; Sarah E Medland; Scott Gordon; Nicholas G Martin; Tracey D Wade; Sarah Cohen-Woods

doi:10.1017/S0033291724001727

Anorexia nervosa polygenic risk, beyond diagnoses: relationship with adolescent disordered eating and behaviors in an Australian female twin population

Psychol Med. 2024 Oct 23;54(13):1-9. doi: 10.1017/S0033291724001727. Online ahead of print.

Authors

Madeleine Curtis^{1

2}, Lucia Colodro-Conde³, Sarah E Medland³, Scott Gordon³, Nicholas G Martin³, Tracey D Wade^{1

2}, Sarah Cohen-Woods^{1

2

4}

Affiliations

¹ Discipline of Psychology, College of Education, Psychology, and Social Work, Flinders University, Adelaide, SA, Australia.
² Blackbird Initiative, Flinders Institute for Mental Health and Wellbeing, Flinders University, Adelaide, SA, Australia.
³ QIMR Berghofer Medical Research Institute, Brisbane, Australia.
⁴ Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.

Abstract

Background: It is well established that there is a substantial genetic component to eating disorders (EDs). Polygenic risk scores (PRSs) can be used to quantify cumulative genetic risk for a trait at an individual level. Recent studies suggest PRSs for anorexia nervosa (AN) may also predict risk for other disordered eating behaviors, but no study has examined if PRS for AN can predict disordered eating as a global continuous measure. This study aimed to investigate whether PRS for AN predicted overall levels of disordered eating, or specific lifetime disordered eating behaviors, in an Australian adolescent female population.

Methods: PRSs were calculated based on summary statistics from the largest Psychiatric Genomics Consortium AN genome-wide association study to date. Analyses were performed using genome-wide complex trait analysis to test the associations between AN PRS and disordered eating global scores, avoidance of eating, objective bulimic episodes, self-induced vomiting, and driven exercise in a sample of Australian adolescent female twins recruited from the Australian Twin Registry (N = 383).

Results: After applying the false-discovery rate correction, the AN PRS was significantly associated with all disordered eating outcomes.

Conclusions: Findings suggest shared genetic etiology across disordered eating presentations and provide insight into the utility of AN PRS for predicting disordered eating behaviors in the general population. In the future, PRSs for EDs may have clinical utility in early disordered eating risk identification, prevention, and intervention.

Keywords: anorexia nervosa; disordered eating; eating disorder; genetics; polygenic risk.