CHICAGO -- New research bolsters evidence that stimulants like Ritalin used for attention deficit problems may stunt children's growth, but it does not address whether the effect is permanent.
Children who took stimulants during the two-year study grew more than half an inch less and gained more than 8 pounds less than those who were not medicated.
The study involved 540 youngsters with attention deficit hyperactivity disorder, who were ages 7 to 9 at the outset of the study and were randomly assigned to receive common treatments that included medication, behavior management, and a combination of the two.
Girls generally reach their final height around age 16 and boys around age 18, so it is too soon to tell if the growth delays continued or were permanent, the researchers said.
American Academy of Pediatrics guidelines that recommend treating ADHD with stimulants and behavior therapy say evidence collected by following youngsters into adulthood indicates the drugs do not cause significant height reduction.
Weight loss, however, is a known potential side effect from long-term stimulant use.
The study, led by University of California at Berkeley researcher Stephen Hinshaw, was funded by the National Institute of Mental Health and appears in this month's issue of Pediatrics.
The results after 14 months of follow-up, published in 1999, suggested that drugs alone or used with behavior therapy were the most effective treatment.
The 24-month follow-up found that drug treatment with or without behavior therapy remained superior, though the effect diminished over time.
ADHD affects 4 percent to 12 percent of US school-age children.