Adults aren’t the only ones being hurt by the opioid crisis. The number of children and teens hospitalized after being poisoned by opioids has more than doubled in the past 16 years, researchers say.

Opioids refer to both prescription painkillers like oxycodone and illegal drugs like heroin. Politicians have paid a lot of attention to opioid abuse, and raised concerns about prescription drugs being too available, but we didn’t how the opioid epidemic has affected children until now. For the study, published this week in JAMA Pediatrics, researchers analyzed 13,052 pediatric hospitalizations due to ingestion of prescription opioids. For teens, they also looked at poisoning due to heroin overdose.

Overall, 3.71 out of 100,000 children up to age 19 were hospitalized for an opioid overdose in 2012. Back in 1997, that number was 1.4 out of every 100,000. In total, about 1.3 percent of these hospitalized children and teens died from the overdose.

The specific numbers for teens ages 15 to 19 were sobering. Hospitalizations for this age group were 10.17 per 100,000 by 2012, compared to 3.69 in 1997. But the biggest jump was in kids under the age of four: the rate in 2012 was 2.62 kids per 100,000, up from 0.86 in 1997.

The researchers call for better prevention programs for teens

There are different reasons for these increases. With little kids, it’s likely that they swallowed their parents’ medication, the researchers say. With the teens, the hospitalization was more likely due to drug abuse or a suicide attempt.

The study is limited. First, the researchers relied on hospital codes to know why someone had been admitted. These codes are sometimes inaccurate and some of the codes could have referred to the same children being hospitalized again. The team didn’t have other medical background on the children aside from what they learned from this one hospitalization. And we don’t know if these trends have continued in the years since 2012.

But this latest research confirms how harmful opioids are in the US. More people died from drug overdoses in 2014 than in any year on record, according to the Centers for Disease Control and Prevention. More than six out of 10 of these overdoses involved an opioid. The paper suggests that opioid abuse will be a “persistent and growing problem in the young” and calls for better prevention programs for teens.