Can magnetic stimulation of the brain shake drug users out of their habits?
By Adam Piore on December 3, 2015
Stefano, a 46-year-old cocaine addict from Padua, Italy, had all but accepted that he might die from his habit. He’d just relapsed after a seven-month stay at a rehab facility, his third failed attempt at getting clean. Stefano (who asked that his last name not be used) couldn’t go more than two days without the drug.
So when he read a magazine article about an unusual new method to treat drug addicts, he figured he didn’t have much to lose. The study described how local researchers were using a technique called transcranial magnetic stimulation to counteract cravings. He would have to sit in a chair while doctors waved a figure-8-shaped wand over his head to fire magnetic waves into his prefrontal cortex. “So almost like a joke, a little bit just to make my family happy, I said I would try,” Stefano says.
Now the results of the study, involving 29 cocaine addicts seeking treatment at a Padua clinic, are out. They suggest that the magnetic stimulation treatment significantly reduced both cocaine use and cravings. Stefano says his desire for cocaine diminished dramatically after several sessions under the magnet. “I can’t explain it,” he says. “It happened very quickly.”
The findings, presented in the European journal Neuropsychopharmacology today by Luigi Gallimberti, a doctor at the University of Padova Medical School, and Alberto Terraneo, a physician who treats addicts, are generating optimism among addiction researchers, because there are no effective drug treatments available for cocaine addicts. There is also a theoretical framework to explain why stimulating the brain with magnets might work, since experiments earlier this year produced similar effects in cocaine-addicted rats.
The doctors in Italy tracked the therapy’s effects using urinalysis to see if addicts were using cocaine, as well as asking them to rate their cravings on a scale of 1 to 10. Of 16 who got the treatment, delivered in once-a-day sessions for five days and then once a week, 11 stayed sober compared to only three of 13 in an untreated group. “Patient improvement is pretty strong,” says Antonello Bonci, scientific director of the intramural research program at the NIH’s National Institute on Drug Abuse and one of the authors of the study. It’s a “first step toward opening a neurobiological treatment for cocaine addiction,” says Bonci. “We have nothing so far to help treat cocaine addicts besides cognitive therapy and psychological support.”
Other scientists noted that the study was small and that the addicts knew whether they were receiving the treatment or in a control group. “You don’t want to get too excited about it, because it’s a very preliminary study,” says Rob Malenka, a Stanford University addiction researcher. But Malenka called the attempt to treat addiction with transcranial magnetic stimulation a “logical extension” of the technology, which is becoming an accepted therapy for some types of hard-to-treat depression.
Invented in the 1980s, TMS has grown in popularity in recent years and was approved by the U.S. Food and Drug Administration as a treatment for depression in 2008. The exact mechanism by which it works is not fully understood. But addiction appears to establish signaling patterns in the brain that compel people to compulsively seek the drug, and applying TMS could disrupt the pattern, just as noise can interfere with a radio signal.
The Italian study sprang out of some recent, and dramatic, discoveries about the complex brain circuitry implicated in addiction. In addicts, areas of the prefrontal cortex that would normally be alight with activity often go dark in the absence of the drug, a state researchers call “hypoactive.” And dulling of brain areas that are crucial to decision-making could be what drives addicts to continue using the drug even when the consequences are ruinous.
Earlier this year, an NIH team led by Bonci showed that cocaine-addicted rats compulsively sought the drug even after learning that doing so consistently produced electric shocks to their feet. But when Bonci and collaborators artificially stimulated brain activity in the prelimbic cortex using a technique called optogenetics, rats that normally were compulsive cocaine seekers suddenly lost interest. When Bonci restored the hypoactive state, the rats resumed compulsive cocaine seeking.
With human addicts, the idea is to create a similar effect using powerful magnets to target a brain area called the dorsolateral prefrontal cortex. Bonci says brain-scanning studies indicate that the effects on brain activity appear to ripple outward, like water pouring over an umbrella. “It’s a network effect,” he says. “It creates a beautiful widespread effect.” He says he has now recruited three centers to participate in larger, blinded study of the addiction treatment, including the TMS center at Northwestern University in Chicago.
Christian Lüscher, a neuroscientist and addiction researcher at the University of Geneva, has also shown he can reverse drug-seeking behavior in mice by targeting different brain regions. He says the Italian study is significant because of how it tries to apply discoveries in basic neuroscience to addicts. It’s likely to encourage researchers to launch larger and more definitive studies, he adds.
For Stefano, the Italian addict, who spoke to MIT Technology Review by telephone, the results have already been life-changing. “It’s a new sensation for me—to have money in my pocket and not have to go out and buy cocaine,” he says. “It’s incredible. People are noticing I have changed.”