Sara Bellum
January 24 2012

More people understand now the harmful effects that smoking has on the body as well as the addictive effects of nicotine. The good news is that teens seem to be getting the message—SBB recently reported that smoking rates among 8th-, 10th-, and 12th-graders are at an all-time low.

But many teens are still smoking—according to the 2011 Monitoring the Future Study PDF [230 KB], 19 percent of high school seniors reported smoking in the past month.

New NIDA research gives yet another reason for teens to avoid lighting that first cigarette—nicotine may “prime” the brain to enhance cocaine’s effects, making it a very dangerous “gateway drug.” That means it could open the door to other drug use.

Nicotine Changes the Brain

Evidence shows that most people who tried drugs like cocaine were first tobacco or alcohol users. This concept of “gateway drugs” has been controversial, mostly because people question whether prior use of drugs like nicotine, alcohol, or marijuana actually leads to later drug use. Before now, studies have not been able to show a biological reason why smoking or other nicotine use could increase a person’s chances of using illegal street drugs.

That changed when NIDA researchers found that mice exposed to nicotine in their drinking water for at least 7 days showed an increased response to cocaine. 

Why did this happen? Researchers recognized that nicotine actually changes the structure of your DNA. It reprograms how certain genes are expressed—in particular a gene that has been related to addiction—and ultimately, it enhances the response to cocaine.

A Turn for the Worse

Moving on from mice, researchers looked at statistics in humans—in particular at when people began nicotine use and their degree of cocaine dependence: Among cocaine users who smoked cigarettes before starting cocaine, the rate of cocaine dependence was higher compared with those who tried cocaine first (before smoking cigarettes).

The study doesn’t mean that every person who smokes cigarettes will eventually become addicted to cocaine. But it does suggest that if a person who smokes cigarettes tries cocaine, their brains may have been changed by nicotine to make it more likely that they will become addicted to cocaine.

Need help quitting smoking? Take a look at these resources from the Centers for Disease Control and Prevention.

Update: Test your knowledge about why smoking is dangerous—take our quiz here.

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