Study links ADHD drugs to growth delays
April 5, 2004
Associated Press

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 1.3 centimetres less and gained more than eight pounds less than those who weren't medicated.

The study involved 540 youngsters with attention deficit hyperactivity disorder, who were aged seven to nine at the outset of the study and were randomly assigned to receive common treatments including medication, behaviour management and a combination of the two.

Girls generally reach their final height around age 16 and boys around age 18, so it's 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 behaviour therapy say evidence collected by following youngsters into adulthood indicates the drugs don't cause any 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 the April issue of Pediatrics.

Initial results after 14 months of follow-up, published in 1999, showed 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 behaviour therapy remained superior, though the effect diminished somewhat over time. The researchers attributed this in part to patients stopping or starting medication.

ADHD, the most common neurobehavioural disorder in childhood, affects four per cent to 12 per cent of U.S. school-age children. Symptoms may include short attention span, impulsive behaviour, and difficulty focusing and sitting still.