Longitudinal Associations Among Bullying by Peers, Disordered Eating Behavior, and Symptoms of Depression During Adolescence

Importance: Bullying by peers has been associated with disordered eating behavior and symptoms of depression among adolescents as both an antecedent and an outcome. Identification of the temporal pattern of associations among bullying by peers, disordered eating behavior, and depression in adolescence is needed for the optimal targeting of intervention and prevention. Objective: To assess the concurrent and longitudinal associations among bullying by peers, disordered eating behavior, and symptoms of depression using a cascade model that controlled for within-time and across-time (ie, stability paths) associations while examining cross-lag effects. Design, Setting, and Participants: In this 5-year longitudinal cohort study, 612 participants of the McMaster Teen Study were included. This ongoing Canadian study examines the associations among bullying, mental health, and educational outcomes. Data collection began in 2008 when students were in grade 5 (10 years of age) and have since been collected annually. Data analysis was performed between August 20 and October 18, 2017. Exposures: Bullying by peers was assessed in grades 7 to 11 using a composite measure of 5 items. Main Outcomes and Measures: Disordered eating behavior was assessed in grades 7 to 11 using the Short Screen for Eating Disorders, and depressive symptoms were assessed in grades 7 to 11 using the Behavior Assessment System for Children-Second Edition. Results: The 612 students included in the analytic sample had a mean age (SD) of 13.03 (0.38) years in grade 7; 331 (54.1%) were girls and 392 (71.1%) were white. Bullying by peers was concurrently associated with disordered eating behavior and depressive symptoms at every time point during the 5-year period (r range [SE], 0.15-0.48 [0.04-0.08]; P < .01). Disordered eating behavior was associated longitudinally with depressive symptoms at every time point (β range [SE], 0.14-0.19 [0.06-0.08]; P < .02) and bullying by peers at 2 time points (β range [SE], 0.12-0.22 [0.06-0.07]; P < .04) in girls and boys. Conclusions and Relevance: Bullying by peers was proximally associated with multiple psychopathologic symptoms, whereas symptoms of disordered eating behavior were a key risk factor for future depressive symptoms and bullying by peers. Interventions aimed at reducing problematic eating behavior in adolescents may attenuate the risk of future depressive symptoms and relational problems.