Abstract
BACKGROUND: Anxiety and eating disorder (ED) symptoms often emerge during adolescence and frequently co-occur, considerably impairing the physical health and psychosocial functioning. Previous research has largely focused on assessing only one direction of the association between anxiety and ED symptoms. Limited understanding exists regarding the potential bidirectional associations and the role of childhood household dysfunction (CHD) in this association. This study aims to examine the bidirectional association between anxiety and ED symptoms in adolescents and further explore whether CHD moderates this association. METHODS: This longitudinal study was conducted among students from nine high schools in China. A total of 8,703 participants (mean [SD] age at baseline, 15.89 [0.60] years; 47.4% female) completed the self-reported questionnaires at baseline (June-August 2023) and at a 4-month follow-up (October-December 2023). Anxiety symptoms were assessed using the 7-item Generalized Anxiety Disorder Scale, and ED symptoms using the Sick, Control, One, Fat, Food questionnaire. Information on eight indicators of CHD was collected at baseline. Cross-lagged panel models (CLPM) were applied to examine the bidirectional association between anxiety and ED symptoms, and moderation analyses were performed to assess the moderating role of CHD. Bonferroni corrections were applied with significance thresholds adjusted for multiple testing. RESULTS: The CLPM results showed that anxiety and ED symptoms exhibit a bidirectional association, with anxiety at baseline predicted subsequent increased ED symptoms (β = 0.13, 95% CI = 0.11-0.15) and ED symptoms at baseline also predicted subsequent increased anxiety symptoms (β = 0.06, 95% CI = 0.04-0.08). The cumulative CHD score was positively associated with both anxiety (β = 0.07, 95% CI = 0.04-0.11) and ED symptoms (β = 0.06, 95% CI = 0.02-0.09) at follow-up, but did not significantly moderate their relationship. Individual CHD indicators demonstrated distinct moderating effects for boys and girls; none of these effects remained significant after Bonferroni correction. CONCLUSIONS: These findings indicate that anxiety and ED symptoms reinforce each other over time, highlighting the potential value of integrated strategies to address both conditions simultaneously. Future research is warranted to clarify the mechanisms underlying this bidirectional association, explore additional moderating factors, and develop targeted prevention strategies.