Abstract P248: Assessing for Bi-Directional Relationships between Body Mass Index and Mental Health Symptoms in Girls

Abstract

Introduction Obesity and mental health problems are increasing in youth; both are often under-treated. The interplay between mental health and body weight development in adolescent girls is not well understood. Hypothesis Bi-directional associations will be established between mental health symptoms (depression and conduct symptoms) and BMI in urban pre-adolescent girls. Methods We examined data from participants in an accelerated longitudinal cohort study of largely disadvantaged urban girls from a single US city (n=2,451; 53% African American). Data were collected annually over 6 years, starting in 2003 when girls were age 8-11. Depression and conduct symptoms (oppositional defiant disorder and conduct disorder symptoms combined) were collected via the validated Child Symptom Inventory (CSI-4) and height and weight were measured. Transitional models assessed for bi-directional associations between mental health symptoms and BMI. Random-effects mixed models identified within-subject and between-subject effects in models examining whether mental health symptoms predicted BMI. All models were adjusted for race, age, and receipt of public assistance, and when applicable, included interaction terms. Results Transitional models showed that prior depression symptoms (β=0.27; p<0.001) predicted an increase in BMI while prior conduct symptoms (β=0.04; p=0.05) showed a small and borderline significant effect on BMI. An increase in prior BMI predicted an increase in depression symptoms (β=0.074, p<0.001) but not conduct symptoms (β=0.028, p=0.125). Mixed models revealed significant between-girl and within-girl effects (β = 0.38 and 0.038, respectively, both with p<0.001) for depression symptoms predicting BMI. Conduct symptoms showed a significant between-girl effect (β=0.51; p=0.045) but a non-significant within-girl effect (β=0.011; p=0.080) when used to predict BMI. Conclusions We identified a clear bi-directional relationship between depression symptoms and BMI in under-privileged girls, and mixed models confirmed that a change in depression score is associated with increased BMI. While an increase in conduct symptoms shows a weak positive association with BMI, the association was not bi-directional. The potential for BMI and depression to each reinforce the other may represent a mechanism for the development of high-risk weight patterns in girls. Early identification of those at risk may facilitate preventive measures for both weight and mental health outcomes.