New brain-imaging approach could help smokers quit

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Caryn Lerman is senior author of the study and director of the University of Pennsylvania Center for Interdisciplinary Research on Nicotine Addiction.

Everybody knows it's really hard for smokers to quit.

Researchers at the University of Pennsylvania think a quick brain scan could someday make quitting easier - or at least more effective.

In a recent study, they found that certain changes in the brain, visible using technology that measures brain activity, predicted better than anything else now available which smokers would quickly relapse - that's most of them - and which might be able to quit without much more than a pep talk.

The advantage of that approach is that about a quarter of smokers could be spared the expense and side effects of smoking-cessation medications, said Caryn Lerman, senior author of the study and director of Penn's Center for Interdisciplinary Research on Nicotine Addiction. The rest could get treatments aimed at strengthening the kind of goal-directed thinking that weakens during cigarette withdrawal.

The hope is for more individualized treatments, which are all the rage in other types of medicine.

The research may also have implications for people who are obese or addicted to other substances. Similar patterns of brain activity have been found to predict loss of control over eating, Lerman said.

Joseph Frascella, a division director for the National Institute on Drug Abuse (NIDA), praised the study for revealing a "potential new path for treatment." He said it dovetails with priorities at NIDA, which funded the research along with the National Cancer Institute and the Pennsylvania Department of Health.

"One of the big pushes here at NIDA is to try to figure out ways to predict how well people are going to do in treatment," Frascella said.

Lerman says the Penn team was the first to show that brain scans could predict quitting success. Their work was published in the syllable-heavy journal Neuropsychopharmacology.

Norman Edelman, a professor of preventive and internal medicine at Stony Brook University School of Medicine and senior scientific adviser to the American Lung Association, said most research on smokers who try to quit has focused on behavior. "This is kind of a logical next step," he said. "It will hopefully inform new approaches to smoking cessation."

The association recommends a combination of medications and behavioral changes to quit smoking. Even under the best of circumstances, only about 30 percent of smokers can stop. Many have to try a number of times before they can stay away from cigarettes, Edelman said.

While the number of U.S. smokers has declined to about 18 percent of adults, he said, the country had made little progress with poorly educated, low-income people.

According to the U.S. Centers for Disease Control and Prevention, about $170 billion in health costs per year can be attributed to smoking. It says that 70 percent of all smokers say they want to quit.

In the Penn study, researchers used functional MRI (fMRI)- a neuroimaging procedure that detects blood flow in the brain - to watch brain function as 80 smokers took a test that measures working memory, an executive function skill that allows people to hold ideas in their head while working with them. It allows people to focus on goals and better block distractions.

They were tested once after they had smoked a cigarette and again when they had gone without smoking for a day.

Then they tried to quit smoking for a week. Only 19 were able to do that. Studies show that smokers who can quit for seven days are likely to last six months or more.

Lerman's team then found a strong-enough correlation between changes in brain activity and quit rates to make predictions with 81 percent accuracy.

The two key brain areas were the dorsolateral prefrontal cortex, which controls working memory, and the posterior cingulate cortex, part of the brain's "default mode." It is a more distractible region that Lerman said is "activated when people are thinking task-irrelevant thoughts," a part that might be vulnerable to "I-really-want-a-cigarette" impulses.

In successful quitters, working memory got more active after that first cigarette-less day and the posterior cingulate cortex less active. The relapsers had the opposite pattern.

Lerman said that drugs or behavioral therapies that strengthen working memory may improve the odds that smokers can quit. Two drugs already in use, varenicline (Chantix) and bupropion (Wellbutrin), can improve working memory. Smokers might also benefit from cognitive exercise training and transcranial direct current brain stimulation, she said. Mindfulness, which teaches practitioners to have more control over their thoughts, also has potential.

Working memory may improve after a longer period of abstinence, but that's not terribly helpful.

"There is some evidence that these cognitive deficits are most severe in the first 24 to 72 hours after a quit attempt," Lerman said. "The problem is that most people don't make it beyond that point."

Asked if it will ever be practical to give everyone who wants to quit smoking an fMRI, Lerman said the scans took only 15 minutes and the price likely will come down.

She and Frascella both said that doctors use expensive scans to examine people with heart disease, cancer, or athletic injuries.

"Many of us believe that addiction is a disease that should be treated just like a broken bone or a tumor," Frascella said.

Edelman was more skeptical: "Whether or not [using fMRI] is a cost-effective tool is wholly unclear to me."

However, he supports research that explores the biological basis of addiction. "We don't want smokers and the diseases they get to be considered self-inflicted," he said.

 


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