National Geographic : 2017 Sep
50 national geographic • September 2017 Insatiable desire, preoccupation, and uncontrol- lable urges. The fast thrill and the need to keep upping the ante to feel the fireworks. An inability to stop, despite promises and resolve. Potenza did some of the first brain-imaging studies of gam- blers and discovered that they looked similar to scans of drug addicts, with sluggish activity in the parts of the brain responsible for impulse control. NOW ThAT ThE PSYChIATRIC establishment accepts the idea that addiction is possible with- out drugs, researchers are trying to determine what types of behaviors qualify as addictions. Are all pleasurable activities potentially addic- tive? Or are we medicalizing every habit, from the minute-to-minute glance at email to the late- afternoon candy break? In the United States the Diagnostic and Statis- tical Manual now lists Internet gaming disorder as a condition worthy of more study, along with chronic, debilitating grief and caffeine-use disor- der. Internet addiction didn’t make it. But it makes psychiatrist Jon Grant’s list of addictions. So do compulsive shopping and sex, food addiction, and kleptomania. “Anything that’s overly rewarding, anything that induces euphoria or is calming, can be addictive,” says Grant, who runs the Addictive, Compulsive and Impulsive Disorders Clinic at the University of Chicago. Whether it will be addictive depends on a person’s vulnerability, which is affected by genetics, trauma, and depression, among other factors. “ We don’t all get addicted,” he says. Perhaps the most controversial of the “new” addictions are food and sex. Can a primal desire be addictive? The World Health Organization has recommended including compulsive sex as an impulse control disorder in its next edition of the International Classification of Diseases, due out by 2018. But the American Psychiatric Association rejected compulsive sex for its latest diagnostic manual, after serious debate about whether the problem is real. The association didn’t consider food addiction. Nicole Avena, a neuroscientist at Mount Sinai St. Luke’s Hospital in New York, has shown that rats will keep gobbling sugar if you let them, and they develop tolerance, craving, and withdrawal, just as they do when they get hooked on cocaine. She says high-fat foods and highly processed foods such as refined flour may be as problem- atic as sugar. Avena and researchers at the Uni- versity of Michigan recently surveyed 384 adults: Ninety-two percent reported a persistent desire to eat certain foods and repeated unsuccessful attempts to stop, two hallmarks of addiction. The respondents ranked pizza—typically made with a white-flour crust and topped with sugar-laden tomato sauce—as the most addictive food, with chips and chocolate tied for second place. Avena has no doubt food addiction is real. “That’s a ma- jor reason why people struggle with obesity.” SCIENCE hAS BEEN MORE SUCCESSFUL in charting what goes awry in the addicted brain than in devising ways to fix it. A few medications can help people overcome certain addictions. For example, naltrexone was developed to treat opioid misuse, but it’s also prescribed to help cut down or stop drinking, binge eating, and gambling. Buprenorphine activates opioid receptors in the brain but to a much lesser degree than her- oin does. The medication suppresses the awful symptoms of craving and withdrawal so people can break addictive patterns. “It’s a miracle,” says Justin Nathanson, a filmmaker and gallery own- er in Charleston, South Carolina. He used hero- in for years and tried rehab twice but relapsed. Then a doctor prescribed buprenorphine. “In five minutes I felt completely normal,” he says. He hasn’t used heroin for 13 years. Most medications used to treat addiction have been around for years. The latest advances in neuroscience have yet to produce a break- through cure. Researchers have tested dozens of compounds, but while many show promise in the lab, results in clinical trials have been mixed at best. Brain stimulation for addiction treatment, an outgrowth of recent neuroscience discoveries, is still experimental. Although 12-step programs, cognitive ther- apy, and other psychotherapeutic approaches are transformative for many people, they don’t work for everyone, and relapse rates are high.