The Fix's Week in Science: January 24, 2012

The Fix's Week in Science: January 24, 2012

By Walter Armstrong 01/24/12

Brain imaging revealed two big firsts about addiction. But how "big" and "first" were they really?

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High-tech cameras catch your brain getting
a kick out of booze.
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Brain imaging—high-tech cameras like MRI and PET scans—have stolen the show in addiction science recently, with two much-publicized studies backing previously unproven if extremely prevalent assumptions. Yet while the pricey photos offer important descriptive data, they—and the media—oversimplify the picture, confusing cause and effect and more.

A new study of "Internet addiction” from the Chinese Academy of Sciences in Wuha made a big buzz last week. The media portrayed it as the first-ever proof of the disorder, but many scientists scoffed. Some even suspected political bias in a nation where Internet access is harshly policed. MRI scans of the brains of 17 adolescents with “Internet addiction disorder”—an official diagnosis in China, unlike in the US—showed abnormalities in the white matter, the tissue through which messages of emotion, cognition, attention and decision making are transmitted. These impairments resemble those associated with alcoholism and other addictions. The study had major limitations: It was tiny—involving just a handful of heavy-gaming kids—and the authors admit there’s no way to know whether the white-matter mess is the cause or the effect of gaming compulsion.

As popular culture applies the "addiction" concept to every imaginable transgression, many scientists push back, pointing out that state-of-the-art neuroscience shows addicted brains share very specific structural and functional irregularities. The 2012 DSM-V will reportedly add only one behavior—gambling—to its list of substance addictions. (Sex and Internet addictions will be second-classed in the appendix.) No one denies that more people are spending many nonproductive, even self-destructive, hours trolling the Web. But classifying a compulsive activity as an addiction may divert research into, and treatment for, its underlying psychological causes, said Colin Drummond, professor of addiction psychiatry at King’s College London. “If people have emotional problems that lead them to use the Internet obsessively, then they obviously need help...but that's quite different from saying that the Internet is addictive. Excessive Internet use is a symptom not a cause of a person's problems.”

Scientists have long assumed that alcohol makes you feel good by triggering the release of endorphins, the brain’s “natural opiates.” A new study using PET scans to record the immediate effects of booze on 13 heavy drinkers (and 12 nondrinkers) now backs this theory—all 25 volunteers got an endorphin hit. More suggestive was the finding that while the natural-opiate levels in the brain’s pleasure centers were the same for all, only the heavy drinkers reported that they felt better the more they drank. (This correlation was seen only in the brain’s reward-processing region.)

That alcoholics find more bliss in the bottle than others may be self-evident, yet PET-scan confirmation increases the promise of investment in R&D. But as with the Chinese MRI imaging, basic questions demand answers. Which came first, the endorphin aberration or the alcoholism? And are heavy drinkers chasing the bottle because their pleasure center is out of whack? Said the Scripps Research Institute's Dr. George Koob, a leading specialist in the neurobiology of addiction: "It could be that some people don't have very good endorphin release and alcohol is the only way for them to get that." The study's lead author, Dr. Jennifer Mitchell, a professor of neuroscience at the University of California San Francisco, hopes that "if we can block that high, eventually alcoholics will learn that drink isn't worth it anymore. That's why we think drug treatment could be effective.”

In fact, naltrexone, which targets the same opiate receptors as alcohol-induced endorphins, is already prescribed to tens of thousands of alcoholics, with mixed benefits. Also available as a once-monthly injection called Vivitrol, naltrexone can partially blunt booze’s buzz. But it also blocks other opiate receptors, causing a decrease in overall pleasure, which may spur further drinking. One innovation would be the development of a more specific opiate antagonist that obstructs only alcohol-related endorphin harbors, not the other pleasure-producing receptors. "We believe this research will help us reverse-engineer naltrexone," Mitchell said. "You don't want to block good feelings in general. You want it to be specific to the alcohol. That's the key."

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Walter Armstrong is the Medical Editor at  Saatchi & Saatchi Wellness and the former deputy editor of The Fix. You can find him on Linkedin.

 
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