Imaging For Clues to Nicotine Addiction, Treatment

by Kayt Sukel

February 27, 2011

Kicking the smoking habit can be quite a challenge—and many smokers can't do it. Some public health scientists hope that neuroimaging studies can help them determine what smoking cessation interventions will be most successful for each person.

In 2008, the Centers for Disease and Control and Prevention’s National Health Interview Survey identified 45 million current adult smokers in the United States. Of those smokers, nearly 60 percent stated they had tried to quit smoking at least once in the past year. And each year, hundreds of thousands of people die from tobacco-related disease; it is the leading cause of preventable death. Public health agencies and foundations spend millions of dollars on a variety of television, print, and Internet campaigns to encourage smokers to quit. But Emily Falk, the director of the University of Michigan's Communication Neuroscience Laboratory, says it can be difficult to know just how well those campaigns may be working.

“It’s a challenge to design interventions for smoking cessation,” says Falk. “How can we tailor messages to best resonate with people—and then how can we choose among those messages which will have the biggest impact at the population level? It’s a bit hit-and-miss now.”

To see if the brain might help answer those questions, Falk and colleagues used functional magnetic resonance imaging (fMRI) recorded neural activity in 28 people as they viewed 15-30 second professional commercials designed to encourage smokers to quit. The researchers were particularly interested in the medial prefrontal cortex (MPFC), a brain area implicated in self-related processes including envisioning one’s future. Their results, demonstrating that a pattern of activation in the MPFC  was a better predictor of whether a person would stop smoking than the person was himself, were published in the Jan. 24 issue of Health Psychology.

“There’s a lot of evidence in the literature that people aren’t necessarily accurate in in reporting what is actually going to persuade them to behave in one way or another,” says Falk. “They’re not necessarily aware of the factors that are ultimately most compelling to them. Neuroimaging allows us to get at some of that information.”

Hannah Chua, a research scientist formerly of the University of Michigan who now works in private industry, agree that studies like these, looking beyond traditional addiction areas in the brain, can help public health agencies to better design smoking cessation campaigns and get the most proverbial bang for their buck. Her own study, published in the Feb. 27 issue of Nature Neuroscience, found that activation in the dorsomedial prefrontal cortex in response to personalized messages about quitting predicted whether a participant would be smoking four months later.

“By looking at health prevention ads or messages in the fMRI, you can understand whether smokers and non-smokers process information differently,” says Chua. “By understanding those differences, we can better understand what may influence a teen to pick up that first cigarette or to encourage one smoker to quit while another one keeps smoking.”

But fMRI studies may offer more than just advertising assistance. Judson Brewer, the medical director of the Yale Therapeutic Neuroscience Clinic, says neuroimaging may also offer predictive value when it comes to selecting a specific treatment program for an addict. He is currently studying brain activation patterns in regions like the dorsal anterior cingulate cortex and the dorsolateral prefrontal cortex to see whether they successfully predict whether an intervention like mindfulness training would help cocaine addicts get clean.

“It doesn’t make sense to put every person in the scanner,” he says. “Ideally, we’ll find some kind of peripheral measure that correlates with a certain type of brain activation pattern and that can help us find the right intervention for an addicted individual and go from there.”

Chua and her colleagues plan to extend their work to look at the role of DNA and the efficacy of addiction interventions. Falk, on the other hand, hopes that medial prefrontal cortex activation will be generalizable to other types of addiction.

“The medial prefrontal cortex first came to our attention in a study that looked at changes in sunscreen use following public service announcements,” says Falk. “We’re hoping that this work will generalize to other kinds of health behavioral change, that it can help design interventions for other domains. But we have a lot of work to do before we can say that for sure.”