Professor: Nicotine does not cause cigarette addiction

Published On:
Thursday, September 3, 2009
Printer-friendly version

An ASU professor is challenging widely held conceptions about smoking, including challenging the view that nicotine is addictive.

Peter Killeen, emeritus professor of psychology in the College of Liberal Arts and Sciences, presented his research findings for the National Institute on Drug Abuse on the Tempe campus Wednesday afternoon.

The talk was called “Reefer Madness: There ain’t no such Thing as Addiction to Nicotine.”

NIDA initially invited Killeen to look into ways to improve scientific research on drug abuse, specifically nicotine addiction.

“I came up with a shocking discovery,” Killeen said. “There’s no such thing as nicotine addiction.”

“It’s time to get our heads straight,” Killeen said. “What causes the tremendously addicting power of cigarettes is the drug cocktail of nicotine,” he said, not nicotine itself.

Before he got into his findings, Killeen said he wanted to make clear that tobacco kills.

“[Tobacco] is the number one preventable cause of death in developing nations,” he said. “Half of the people who are lifelong smokers will die of smoking-related illness.”

And yet, he said, the mass addiction to cigarettes and the public knowledge of tobacco’s deadliness creates a paradox.

There is something missing in the equation, Killeen said: A sufficient answer about what causes the powerful addiction.

For years, researchers have maintained that nicotine is the cause of tobacco addiction.

But Killeen said new evidence suggests otherwise.

“A large portion of the research on tobacco studies is done on nicotine. But the research has not been very reinforcing,” Killeen said. “Nicotine in itself is not very rewarding. You can go to any drugstore and buy a packet of Nicorette chewing gum.”

But people don’t overdose on Nicorette chewing gum, he said.

“Studies have shown that none of the nicotine replacement therapies — chewing gum, inhalers, patches — none of those are addictive,” he said. “Nicotine is not addictive. So what’s going on?”

The cause of addiction is the release of monoamine oxidase inhibitors, or MAOIs, along with nicotine, Killeen said.

While nicotine affects the release of dopamine, or the “reward hormone” that affects emotions and movement, MAOIs help regulate dopamine levels, Killeen said.

“When you put together something that directly releases dopamine and another thing that helps the brain clean up excess dopamine, you’ve got a one-two punch,” he said. “It is my hypothesis that it’s a combination of nicotine with some of these other chemicals that causes the powerful addiction.”

Killeen said publicizing his research is important in moving forward with the study.

“Not everybody knows that nicotine is not addictive,” he said. “This negatively affects both the research and public opinion.”

Many people are hesitant to accept the research’s implications, but Killeen said his hypothesis is hard to deny.

“I presented this position to 20 of the world’s experts,” he said. “And though some were shocked and insulted, no one could argue that my case was untrue.”

ASU Director of Campus Health Services Allan Markus said it would take a thorough clinical trial to further prove Killeen’s hypothesis.

“The overall scientific evidence from research, going back many, many years, proves that nicotine is addictive,” Markus said.

Anthropology sophomore Marisa Rios said the social aspect of smoking appeals to her.

“What makes me smoke is not the jonesing or need for a fix every 15 minutes,” she said. “What makes me smoke is stress or just wanting something to do.”

Killeen said even though the addiction to cigarettes is highly chemical, a large part of quitting comes from creating distance from these social smoking situations.

Of 100 smokers who decided to quit, only 10 are still abstinent after a year, meaning there is a 90 percent relapse rate, Killeen said.

“There’s no such thing as a cure, in the sense that there’s always a very small but real possibility of relapse [for successful quitters],” Killeen said. “You can’t ever let down your guard.”

Reach the reporter at jessica.testa@asu.edu.