A new study suggests that because e-cigarettes contain nicotine, they may be a "gateway drug" for users.
The research, published in the New England Journal of Medicine, suggests that e-cigarettes could make users more likely to use other drugs, particularly cocaine. Denise Kandel and Eric Kandel, the researchers behind the study, have looked at nicotine's effects for years, and found that nicotine enhanced cocaine's effects in mice by "activating a reward-related gene and shutting off inhibition," Time reports.
The Kandels suggest nicotine-containing products, including cigarettes, may have similar effects on humans. "This is a powerful facilitator for addiction to cocaine and perhaps other drugs as well," Eric Kandel told Time. "The fact that this is a significant influence on encouraging or facilitating the use of other drugs is never discussed, and it's just a major omission."
E-cigarettes have received a fair share of criticism in recent weeks, with the American Heart Association calling for stricter regulations and the World Health Organization advocating a ban on e-cigarette sales to minors. There is still debate as to whether e-cigarettes can help smokers quit the habit.