Depression, Cortisol Reactivity, and Obesity in Childhood and Adolescence

Purpose: Depression in childhood is associated with higher body mass index (BMI), a relative measure of overweight, and overweight is associated with cortisol reactivity, indexed by heightened secretion of cortisol in response to a stressor. The current study uses a mediation model to examine the associations between symptoms of depression, cortisol reactivity and BMI in a cross-sectional study. Methods: Children (N = 111) 8 to 13 years old and a parent completed structured interviews. The Child Behavior Checklist was used to assess symptoms of depression, and cortisol reactivity to the Trier Social Stress Test for Children was measured. Physical examinations were used to determine BMI (kg/m²) and pubertal stage. Results: Depression was positively associated with BMI in both sexes. Age and pubertal stage were not significantly associated with BMI, nor was physical activity and BMI in a model including depression. In girls, but not in boys, the association between depression and BMI was mediated by cortisol reactivity. Conclusions: The current findings attest to the significance of psychologic states as potential components in models of childhood obesity, and provide conceptual and empirical support for the inclusion of cortisol reactivity in these models.