| Objectives: To investigate whether Attention Deficit Hyperactivity Disorder (ADHD) is associated with abnormal bodyweight (underweight or obesity) in a national sample of Canadian children.;Methods: Data were derived from children aged 4-11 years in the National Longitudinal Survey of Children and Youth (N =10, 200). Data were analysed using linear modelling and logistic regression, controlling for variables known to be associated with ADHD and bodyweight, including age, sex, SES, medication, and other psychological difficulties. We examined ADHD using an ADHD symptom scale (dimensional approach), symptom severity rating (no, mild, moderate or severe symptoms), a proxy ADHD diagnosis (to approximate a clinical categorical condition), and hyperactive/impulsive and inattentive ADHD symptom severity.;Results: Higher scores on the ADHD scale were associated with increased odds of obesity (adjusted odds ratio [AOR] = 1.04, 95% confidence interval [CI95] = 1.02-1.06, p = .000), but not underweight. Children with mild (AOR = 1.39, CI95 = 1.16-1.67, p= .001) and moderate (AOR = 1.63, CI95 = 1.31-2.01, p =.000) ADHD symptoms had higher odds of obesity relative to children with no symptoms. Among children not taking ADHD medication, those with severe ADHD symptoms also had higher odds of obesity (AOR = 1.43, CI95 = 1.02-2.01, p = .040). In terms of specific ADHD symptom dimensions, low-moderate (AOR = 1.40, CI95 = 1.19-1.64, p =.000) and severe (AOR = 1.39, CI95 = 1.05-1.85) hyperactive/impulsive and low-moderate (AOR = 1.30, CI95 = 1.15-1.46, p = .000) inattentive symptoms of ADHD were significantly associated with increased odds of obesity. On the other hand, proxy ADHD diagnosis was associated with higher odds of underweight (AOR = 1.34, CI95 = 1.01-1.78, p = .046), but not obesity. Finally, when bodyweight classification was entered as the predictor variable and ADHD variables served as the outcome variables, the pattern of results was essentially the same.;Conclusions: Results demonstrated a relationship between ADHD and abnormal bodyweight, although the associations were different for underweight and obesity. The association between ADHD and obesity also varied with symptom severity, suggesting a non-linear relationship. Further research is needed to clarify the mechanisms involved in this complex relationship. |
