The Effect of ADHD Stimulant Treatment on Weight Categories in Children and Adolescents.

Objective: Pediatric overweight and obesity represent a growing public health concern with significant long-term implications. In children diagnosed with attention-deficit/hyperactivity disorder (ADHD), stimulant medications may alter appetite, potentially impacting body weight and growth patterns. However, real-world data on the effect of these treatments on body mass index (BMI) classification remains scarce. We aimed to evaluate the effect of ADHD stimulant therapy on transitions in the BMI categories among children. Study Design: We conducted a large-scale observational cohort study assessing longitudinal changes in BMI classification following the initiation of stimulant treatment, utilizing data from Clalit Health Services, Israel's largest healthcare provider. BMI was categorized into four groups: normal weight, overweight, obesity, and severe obesity. Subgroup analysis was performed by sex and age groups: <7 years; >7 <13 years and >13 <18 years. Results: At baseline, 26,930 children met the study inclusion criteria. 12,448 (46%) were classified as overweight or obese. Most children with normal weight at baseline maintained their BMI classification (90%). 48% of children with overweight, 42% with obesity, and 29% with severe obesity transitioned to a lower BMI category. 39% of children with underweight transitioned to normal weight. Similar patterns in BMI category transitions were observed between sexes. Transition to a lower BMI category was more prevalent in the younger age group. Conclusions: Stimulant therapy for ADHD is associated with significant shifts in BMI classification among pediatric patients. While many children, especially younger with higher baseline BMI, experienced improvements in weight status, a notable minority exhibited weight gain. These findings underscore the importance of routine BMI monitoring and weight management strategies during ADHD treatment.