NEW YORK — Significant growth slowdown during treatment with stimulants may occur in a small subset of children who require closer monitoring and referral, Dr. Harold E. Carlson said at a psychopharmacology update sponsored by the American Academy of Child and Adolescent Psychiatry.
“It's pretty well established that children who receive stimulants, typically for [attention-deficit hyperactivity disorder], can have some slowing of their growth,” said Dr. Carlson, head of endocrinology at the State University of New York at Stony Brook.
Height velocity, or yearly growth, typically slows for the first few years of stimulant therapy and then resumes at a nearly normal rate. Pubertal development is normal. Final adult height is usually normal with long-term use of stimulants. However, a small subset of patients, perhaps 10%, have a more significant slowdown of growth, Dr. Carlson said.
“I don't think anybody has a good handle on how many [children experience this significant slowdown], and we certainly don't have a good idea as to how to identify them ahead of time,” he said.
Because the secretion of growth hormone in these children is normal, researchers have speculated that the slowdown may be related to a decrease in food intake while on stimulants, he said.
The slowdown is greater in prepubertal children, boys, children who are taller or overweight at baseline, and children who use sustained-release formulations.
Little data exist on the final adult height of children who have taken stimulants, Dr. Carlson said.
In one study, 97 boys aged 4–12 years who were treated with methylphenidate for an average of 36 months grew to a final adult height at 21–23 years of age that was similar to the final adult height of other males in their family and community, and of unmedicated controls. These data are “reassuring,” Dr. Carlson said, but “we want to emphasize that there may well be a subset of children who do have more significant slowing of growth.”