More adolescents failed to quit smoking in 2020 than in any of the previous 13 years, according to new data published in the Journal of the American Medical Association. 2020 was the first year the research team had data on attempts to quit e-cigarettes, and it showed that around 4 percent of adolescents unsuccessfully attempted to quit e-cigarettes.

E-cigarettes have been pushed to adult smokers as an alternative to traditional, combustible cigarettes — some evidence shows they might be less dangerous, and there’s mixed evidence that they could push adults to quit smoking altogether. But the picture might be different for teens, who started vaping in droves in 2018 and are far less likely to be cigarette smokers first. The new analysis shows that for younger people, the introduction of e-cigarettes made quitting more difficult.

The new study includes data from the Monitoring the Future study, which surveys eighth, 10th, and 12th grade students. It includes a question asking the participants if they had ever tried to stop smoking and found that they could not. In 2020, it added a question asking if they’d ever tried to stop vaping nicotine and found that they could not. From 1997 to 2019, the survey found that the number of students who reported using cigarettes and the percent of adolescents estimated to have tried and failed to quit smoking both dropped.

But in 2020, those numbers popped back up. More students reported smoking cigarettes, and the analysis estimated that around 2 percent tried and failed to quit smoking. Combined with the 4 percent who tried and failed to quit vaping, the paper found that just under 6 percent of adolescents had unsuccessfully tried to quit using nicotine products that year.

The data comes as the Food and Drug Administration continues to try and create e-cigarette and vaping policies that benefit adult smokers while limiting their use by kids and teenagers. “The contribution of e-cigarettes to unsuccessful nicotine quit attempts among adolescents is substantial and warrants consideration as the US formulates policies to regulate e-cigarettes,” the authors of the new paper wrote.

The agency is still reviewing applications from some e-cigarette companies, despite having a September 2021 deadline to tell companies if they can keep products on the market. So far, it has authorized tobacco-flavored products from one company and rejected over 200 others. It has yet to rule on Juul, the company most tightly linked to kids and vaping.