ADHD medication can slow growth in teenage boys

Adolescent boys with attention deficit hyperactivity disorder (ADHD) are more likely to be shorter and slimmer than their same-age peers, according to a new study published in the Medical Journal of Australia.

Dr Alison Poulton from the University of Sydney and her coauthors investigated the influence of stimulant medication on the growth and physical development during puberty of adolescent boys with ADHD.

The study found that prolonged treatment for more than three years with stimulant medication was associated with a slower rate of physical development during puberty.

“Our findings suggest that stimulant medication delays the rate of maturation during puberty, including the timing of the peak growth rate, but not the onset of puberty,” said Dr Poulton, from Sydney Medical School.

“To maintain an adequate rate of growth during puberty we recommend that boys on ADHD stimulant medication should take the lowest dose that adequately treats their ADHD,” said Dr Poulton.

The researchers recruited 65 boys aged between 12 and 16 years who had ADHD and had been on stimulant medication for more than three years. Compared with boys without ADHD, boys aged between 12 and 14 years with ADHD had significantly lower weight and body mass index, and those aged between 14 and 16 years with ADHD had significantly lower height and weight.

There was no difference in pubertal development between boys with and those without ADHD aged between 12 and 14 years, but those aged between 14 and 16 years with ADHD showed significant delay.

The study also found there was a significant inverse relationship between the dose of stimulant medication and the growth rate among boys aged between 14 and 16 years with ADHD.

The authors found that boys who had taken stimulant medication for ADHD for a minimum of three years until 14 years of age showed slower weight gain but comparable height and physical development related to puberty to boys of the same age without ADHD.

However, boys aged between 14 and 16 years with ADHD were significantly behind their peers in height and pubertal development.

(Source: The University of Sydney: Medical Journal of Australia)