Body Mass Indices of Girls with and without ADHD: Developmental Trajectories from Childhood to Adulthood

Objective: We examined the predictive relation between childhood-diagnosed ADHD and trajectories of body mass index (BMI) from childhood to adulthood in an all-female sample, accounting for socioeconomic status (SES), childhood comorbidities (e.g., depression/anxiety), and stimulant usage. Childhood executive functioning (i.e., planning, sustained attention, and response inhibition) was also evaluated as a possible predictor of BMI trajectories. Method: We utilized longitudinal data from a full sample of 140 girls diagnosed with ADHD in childhood and 88 comparison girls matched on age and ethnicity. Girls were 6-12 years old at the first assessment and followed prospectively for 16 years. Data were collected on their BMI and stimulant medication usage across four evaluation waves. Using latent growth curve modeling, we evaluated the BMI trajectories of girls with ADHD and the comparison sample from childhood to adulthood. Results: Although there was no significant difference in initial childhood BMI, girls with ADHD increased in BMI at a significantly faster rate than comparison girls across development, even when adjusting for covariates. Significant differences in BMI first emerged in adolescence; by adulthood, 40.2% of the ADHD sample met criteria for obesity versus 15.4% of the comparison sample. When covarying ADHD diagnosis, executive functioning measures were not significantly predictive of BMI increase. Adjusting for stimulant medication usage within the ADHD sample did not alter core findings. Conclusions: We discuss health-related implications for girls with ADHD, potential underlying mechanisms, and how our findings may inform both ADHD and obesity interventions.