Rethinking the association between overweight/obesity and ADHD in children: a longitudinal and psychosocial perspective

This study examines the association between attention-deficit/hyperactivity disorder (ADHD) and overweight/obesity in a large-scale longitudinal study of children, whilst controlling for a range of psychosocial factors. Data were obtained from Growing Up in Ireland, a nationally representative and longitudinal study of approximately 6,500 children who were assessed at 9 and 13 years of age. Body mass index (BMI) was determined using measured height and weight, ADHD status was determined by parent reports of professional diagnoses and ADHD symptoms were measured using the Strengths and Difficulties Questionnaire (SDQ). The associations between ADHD status, ADHD symptoms (SDQ) and BMI category at age 9 and 13 were evaluated using logistic regression. Adjustments were made for child factors (sex, developmental coordination disorder, emotional symptoms, conduct problems, birth weight and exercise) and parental factors (socio-economic status, parental BMI, parental depression, and maternal smoking and alcohol use during pregnancy). Logistic regression indicated that ADHD status was not associated with BMI category at 9 or at 13 years of age, but children with ADHD at 9 years were significantly more likely to be overweight/obese at 13 years than those without ADHD. However, when other child and parental factors were adjusted for, ADHD status was no longer significantly associated with weight status. Female sex, low levels of exercise, overweight/obese parents and prenatal smoking during pregnancy consistently increased the odds of childhood overweight/obesity. In general populations, ADHD and overweight/obesity co-occur, but a host of other psychosocial factors may be involved in their association.