A study published in a major medical journal says that e-cigarettes could be a “gateway” drug to harder substance use.

In this photo illustration a woman smokes an e-cigarette on April 2, 2014 in London, England. Wales is considering a ban on the smoking of electronic cigarettes in enclosed public places.  (Peter Macdiarmid/Getty Images)

In this photo illustration a woman smokes an e-cigarette on April 2, 2014 in London, England. Wales is considering a ban on the smoking of electronic cigarettes in enclosed public places. (Peter Macdiarmid/Getty Images)

In recent months, electronic cigarettes have been subject to debate and research as some hail them for reducing some of the harmful effects associated with traditional cigarette smoking, while others maintain that nicotine is still an addictive substance that merits government regulation.

“While e-cigarettes do eliminate some of the health effects associated with combustible tobacco, they are pure nicotine-delivery devices,” Dr. Denise B. Kandel with Columbia University Medical Center and co-author of the study published in the New England Journal of Medicine this week said in a statement.

The researchers reviewed previous research that considered the possibility of nicotine being a gateway drug. These studies showed how nicotine can alter the brain and how it responds to other drugs like marijuana and cocaine.

“Our findings provided a biologic basis for the sequence of drug use observed in people,” Dr. Eric Kandel, Denise Kandel’s husband who is also a co-author on this study, said. “One drug alters the brain’s circuitry in a way that enhances the effects of a subsequent drug.”

“E-cigarettes have the same physiological effects on the brain and may pose the same risk of addiction to other drugs as regular cigarettes, especially in adolescence during a critical period of brain development,” the study authors wrote. “We don’t yet know whether e-cigarettes will prove to be a gateway to the use of conventional cigarettes and illicit drugs, but that’s certainly a possibility. Nicotine clearly acts as a gateway drug on the brain, and this effect is likely to occur whether the exposure comes from smoking cigarettes, passive tobacco smoke or e-cigarettes.”

While the Kandels studied previous research that was conducted on the brains of adult mice, Eric Kandel speculated that the effect of the brain alteration as a result of nicotine exposure could be even stronger in adolescents, which he said is worrisome with the growing popularity of e-cigs among young adults.

“The emergence in our society of new recreational pharmaceuticals such as E-cigarettes and legalized marijuana, while justifiable on one level, may have adverse consequences of which we are not fully aware. The Kandels’ research on ‘gateway’ drugs demonstrates such grave potential consequences,” Jeffrey Lieberman with CUMC said of the team’s conclusions.

Dr. Shanta Rishi Dube with the Georgia State University, who was not involved in the research, told Reuters that the team’s findings citing e-cigarettes as having the potential for being a gateway drug “appear valid.”