E-cigarettes are being used by people who wanted to reduce or quit smoking. However, a study suggests that it has an opposing effect to teens — it predisposes them to become conventional cigarette smokers.

The findings of the study were published in the journal of JAMA, according to the report of Reuters.

Researchers from University of Southern California found out that teens in the United States who have tried electronic cigarettes may become more than twice as likely to progress to smoking conventional cigarettes compared to those who have never tried it.

The latest study of the researchers from USC involved 2,500 high-school students from Los Angeles. The survey about tobacco use was conducted three times over the course of a year.

The study began in the fall 2013 — the students were about 14 and not smoking. At the start of the study, about 222 students or nine percent admitted they had tried the e-cigarettes, ABC News has learned.

Nearly one-third of them tried cigarettes, water pipes or cigars within the following six months compared to the eight percent who never tried the e-cigarettes.

Dr. Nancy Rigotti, an expert in tobacco research at Massachusetts General Hospital, sent an email to Reuters Health stating, "Adolescent brains appear to be especially susceptible to becoming addicted to nicotine when exposed."

In an email sent by lead author Adam Leventhal, of the University of Southern California Health, Emotion and Addiction Laboratory, he stated, "Our research does suggest that teens who use e-cigarettes for recreational purposes may be more likely to later advance to trying regular cigarettes and other smokable tobacco products."

It was reported that in 2014 FDA proposed rules to ban the sale of e-cigarettes to minors and include the device in the list of its tobacco regulated products. The law prohibiting the sale of vapes to minors has been reportedly proposed in some states.

Meanwhile, in Douglas County, Colorado, there is already a proposed city ordinance that would expand the definition of banned tobacco products for under 18 to include the emerging electronic device.

The second and final reading of the proposed county ordinance will be on Sept. 8, Castle Rock News Press reported. The public will be given the opportunity to comment.