Objective: To investigate the growth and pubertal attainment of boys with attention deficit hyperactivity disorder (ADHD) on stimulant medication.
Design, setting and participants: Longitudinal study of boys aged 12.00-15.99 years at recruitment in 2005-2011, with stimulant-treated ADHD for at least 3 years, attending three paediatric practices (subjects), compared with longitudinal data from 174 boys from the Nepean longitudinal study (controls).
Main outcome measures: Subjects' growth parameters before treatment were compared with controls aged 7 or 8 years; growth parameters and longitudinal changes on treatment to ages 12.00-13.99 and 14.00-15.99 years were compared with controls reviewed at 13 and 15 years of age, respectively. The subjects' pubertal staging and height velocity were related to their treatment history.
Results: Sixty-five subjects were recruited; mean duration of treatment was 6.3 ± 1.9 years. At baseline, their growth parameters were not significantly different from those of the controls after adjusting for age. Compared with the controls, after adjusting for current age and baseline growth parameter z score, subjects aged 12.00-13.99 years had significantly lower weight and body mass index (P < 0.01), and those aged 14.00-15.99 years had significantly lower height and weight (P < 0.05). At 12.00-13.99 years of age, the subjects were comparable to the controls in their pubertal development adjusted for age, but those aged 14.00-15.99 years reported significant delay (mean Tanner stage, 3.6 for subjects v 4.0 for controls; P < 0.05). The dose of medication was inversely correlated with the height velocity from baseline to 14.00-15.99 years of age (P < 0.05).
Conclusions: Prolonged treatment (more than 3 years) with stimulant medication was associated with a slower rate of physical development during puberty. To maintain adequate height velocity during puberty, we recommend keeping the dose as low as possible.