Children and adolescents are getting fewer prescription drugs than they did in years past, according to a study that looks at a cross-section of the American population."The decrease in antibiotic use is really what's driving this overall decline in prescription medication use that we're seeing in children and adolescents," says Craig Hales, a preventive medicine physician at the Centers for Disease Control and Prevention's National Center for Health Statistics and lead author of a study published Tuesday in JAMA.Hales says that's a good thing. "Thirty percent of antibiotic prescriptions are unnecessary and potentially dangerous," he says. They're often given for colds and other viral infections, where they are useless. And they may have side effects. Antibiotic overuse also increases the risk that these drugs lose their curative powers.The study is based on data from the National Health and Nutrition Examination Study, which included more than 38,000 children and adolescents. The study compared prescription drug use from 1999 to 2002 with prescriptions given in 2011 to 2014, the last period for which data were available.Overall, the proportion of children and teenagers getting prescriptions dropped from about 25 percent to 22 percent. Prescriptions for some drugs increased, such as for treatments for asthma, contraception and attention-deficit and hyperactivity disorder (ADHD).The survey also noted a large gap in prescription use among children and adolescents who were insured versus those who weren't. Some 23 percent of insured youth had recently taken a prescription of some sort, compared with 10 percent of those who were uninsured.It's hard to know how exactly to interpret many of the findings, says Gary Freed, a pediatrician and researcher at the University of Michigan Medical School, who was not involved with the research. That gap could be a sign of overuse among the insured or underuse in the uninsured."It's very common for people who don't need things but want to pay for them, to be able to get them," Freed says. "It's also possible that some children who really need medications, if they're uninsured, don't get them."The study doesn't provide information that can address key questions like that.For example, antihistamines are widely overused or inappropriately used in children, Freed says. The study shows a decline in prescriptions for antihistamines, but that may simply be because many of these drugs came available without a prescription during the study period."So the fact that the prescribing went down may mean something good or it may simply mean that people are going to the drugstore and buying those same medications," Freed says.Freed says he can't even say whether the overall use of prescription drugs in children and teen-agers, at 22 percent in a typical 30-day period, is a sign of overuse or underuse."The danger is thinking 'oh my goodness that's so many kids getting medications,' " he says. "But at the same time, before we make that conclusion we have to know whether those were appropriate or not appropriate."More children than ever are alive today because they've survived diseases that require medical treatment, he notes. Yet certain drugs are still overused. And in other instances, such as ADHD drugs, there's disagreement about when treatment is appropriate.Those questions require more directed – and more expensive – studies. Hales hopes that his broad-brush findings will stimulate that further research.You can contact Richard Harris at rharris@npr.org. Copyright 2018 NPR. To see more, visit http://www.npr.org/.