The number of drugs dispensed to US minors has dropped slightly over the past decade, bucking the rise in prescriptions to adults, with a drop in the use of antibiotics standing out, according to a government report.

But use of other drugs rose, with stimulants used to treat attention deficit hyperactivity disorder (ADHD) leading the pack, said the report, published in the journal Pediatrics.

From 2002 to 2010, the use of ADHD drugs grew by 46 per cent, or some 800,000 prescriptions a year, wrote researchers from the US Food and Drug Administration.

The top drug dispensed to adolescents was the stimulant methylphenidate, also known as Ritalin, with more than four million prescriptions filled in 2010.

“What the article is suggesting is that the number of children that we are treating for attention deficit disorder has gone up,” said Scott Benson, a child and adolescent psychiatrist and a spokesperson for the American Psychiatric Association.

“For the most part I think the overall increase reflects a reduction in the stigma. It used to be 'You're a bad parent if you can't get your child to behave, and you're a doubly bad parent if you put them on medicine'.”

Antibiotic use fell by 14 per cent, suggesting that efforts to curb rampant overuse of the drugs “may be working,” the researchers wrote.

Experts say antibiotics are commonly used to treat infections caused by viruses, although they only work against bacteria - and that has fueled the growth of drug-resistant superbugs.

The findings were based on data from healthcare research firm IMS Health and do not include drugs given at hospitals.

Overall, there were 263 million filled prescriptions to minors in 2010, down seven percent since 2002. After taking population changes into account, that corresponds to a nine-percent drop.

By contrast, adult prescriptions rose by 11 per cent.

Prescription drug classes that showed marked dips among children included allergy medicines, cough and cold drugs, painkillers and antidepressants.

Apart from ADHD drugs, asthma medicine and birth control pills also showed increases.

The FDA said it could not explain the reasons behind the changes.