The first-ever study of electronic cigarette use among youths found that smoking is on the rise.

The study performed by a team of researchers at the Yale School of Medicine discovered that use of e-cigarettes — battery powered devices that heat nicotine cartridges into a vapor which the user can then inhale — doubled in a sample of high school students between February 2010 and June 2011. According to researchers interviewed, the finding adds to a growing debate about whether e-cigarettes are a gateway to traditional cigarettes or an effective way of quitting.

The researchers interviewed students from two high schools — one in New Haven and one in New York — about their use of traditional tobacco products and e-cigarettes. In February 2010, 0.9 percent of 1719 respondents said that they had used e-cigarettes in the past 30 days whereas in June 2011, 2.3 percent of 1345 students said they had used such products over the last month.

The team also looked at other factors that correlated with e-cigarette use. While smoking traditional cigarettes had by far the strongest correlation, the study authors also found that Caucasian students and high school seniors were at an increased risk of use e-cigarette use.

Even though youths often use e-cigarettes and combustible cigarettes together, the correlation does not prove that e-cigarettes are a gateway to the traditional product, said Stan Glantz, the director of the Center for Tobacco Research & Education at the University of California, San Francisco, who was not involved in the study. Glantz added he is concerned that e-cigarette marketers specifically target youths.

“The concern is that the product looks like a regular cigarette, so it provides a type of modeling behavior for youth,” said Deepa R. Camenga, study author and instructor in pediatrics at the Yale School of Medicine.

Camenga and Glantz disagreed on whether e-cigarettes can have the opposite effect: helping people quit smoking traditional cigarettes.

According to Glantz, the claim that e-cigarettes help people quit is not supported by evidence, citing a handful of studies that suggest e-cigarettes actually discourage quitting because people tend to use both types of cigarettes indefinitely. On the other hand, Camenga said there are studies showing that e-cigarettes are helping people quitting traditional cigarettes.

“They show that people are able to get off cigarettes, [but] we don’t really know if it allows them to quite long term.” she said.

E-cigarettes are currently unregulated by the FDA, Camenga said. On Dec. 30, New York City made it illegal to smoke e-cigarettes wherever smoking traditional cigarettes is banned.

The study appears in the January 2014 issue of Addictive Behaviors.