Slowing of growth in height and weight on stimulants: A characteristic pattern

Objective: The aims of the present study were to describe the growth pattern of children starting stimulant medication and to analyse the changes over time in height, weight and height velocity in a cohort of treated patients. Methods: Retrospective review of growth data from files of all newly treated patients with attention-deficit/hyperactivity disorder in one paediatric practice. Forty-four boys and seven girls were treated for 6-42 months with either dexam-phetamine (n = 32) or methylphenidate (n = 19). Results: During the first 6 months on stimulant medication 44 children (86%) had a height velocity below the age-corrected mean and there was weight loss in 39 (76%). The height and weight standard deviation score (SDS) showed a progressive decline that was statistically significant after 6 and 18 months (P < 0.001, paired t -test). The height velocity was significantly attenuated for the first 30 months (P < 0.01), being lowest during the first 6 months. The mean height deficit during the first 2 years was approximately 1 cm/year. The change in weight SDS was 2.4 times the change in height SDS after 30 months on treatment with a significant correlation (Pearson's correlation coefficient r = 0.88, P < 0.001). Conclusions: Stimulant medication is associated with a decrease in height and weight SDS during the first 6-30 months with a characteristic pattern on the growth chart.