How Science Is Unlocking the Secrets of Addiction
We’re learning more about the craving that fuels self-defeating habits—and how new discoveries can help us kick the habit.
PATRICK PEROTTI SCOFFED when his mother told him about a doctor who uses electromagnetic waves to treat drug addiction. “I thought he was a swindler,” Perotti says.
Perotti, who is 38 and lives in Genoa, Italy, began snorting cocaine at 17, a rich kid who loved to party. His indulgence gradually turned into a daily habit and then an all-consuming compulsion. He fell in love, had a son, and opened a restaurant. Under the weight of his addiction, his family and business eventually collapsed.
He did a three-month stint in rehab and relapsed 36 hours after he left. He spent eight months in another program, but the day he returned home, he saw his dealer and got high. “I began to use cocaine with rage,” he says. “I became paranoid, obsessed, crazy. I could not see any way to stop.”
When his mother pressed him to call the doctor, Perotti gave in. He learned he would just have to sit in a chair like a dentist’s and let the doctor, Luigi Gallimberti, hold a device near the left side of his head, on the theory it would suppress his hunger for cocaine. “It was either the cliff or Dr. Gallimberti,” he recalls.
Gallimberti, a gray-haired, bespectacled psychiatrist and toxicologist who has treated addiction for 30 years, runs a clinic in Padua. His decision to try the technique, called transcranial magnetic stimulation (TMS), stemmed from dramatic advances in the science of addiction—and from his frustration with traditional treatments. Medications can help people quit drinking, smoking, or using heroin, but relapse is common, and there’s no effective medical remedy for addiction to stimulants like cocaine. “It’s very, very difficult to treat these patients,” he says.
More than 200,000 people worldwide die every year from drug overdoses and drug-related illnesses, such as HIV, according to the United Nations Office on Drugs and Crime, and far more die from smoking and drinking. More than a billion people smoke, and tobacco is implicated in the top five causes of death: heart disease, stroke, respiratory infections, chronic obstructive pulmonary disease, and lung cancer. Nearly one of every 20 adults worldwide is addicted to alcohol. No one has yet counted people hooked on gambling and other compulsive activities gaining recognition as addictions.
In the United States an epidemic of opioid addiction continues to get worse. The Centers for Disease Control and Prevention reported a record 33,091 overdose deaths in 2015 from opioids, including prescription painkillers and heroin—16 percent more than the previous record, set just the year before. In response to the crisis, the first ever U.S. surgeon general’s report on addiction was released in November 2016. It concluded that 21 million Americans have a drug or alcohol addiction, making the disorder more common than cancer.
After spending decades probing the brains of drug-loving lab animals and scanning the brains of human volunteers, scientists have developed a detailed picture of how addiction disrupts pathways and processes that underlie desire, habit formation, pleasure, learning, emotional regulation, and cognition. Addiction causes hundreds of changes in brain anatomy, chemistry, and cell-to-cell signaling, including in the gaps between neurons called synapses, which are the molecular machinery for learning. By taking advantage of the brain’s marvelous plasticity, addiction remolds neural circuits to assign supreme value to cocaine or heroin or gin, at the expense of other interests such as health, work, family, or life itself.
“In a sense, addiction is a pathological form of learning,” says Antonello Bonci, a neurologist at the National Institute on Drug Abuse.
Gallimberti was fascinated when he read a newspaper article about experiments by Bonci and his colleagues at NIDA and the University of California, San Francisco. They had measured electrical activity in neurons in cocaine-seeking rats and discovered that a region of the brain involved in inhibiting behavior was abnormally quiet. Using optogenetics, which combines fiber optics and genetic engineering to manipulate animal brains with once unimaginable speed and precision, the researchers activated these listless cells in the rats. “Their interest in cocaine basically vanished,” Bonci says. The researchers suggested that stimulating the region of the human brain responsible for inhibiting behavior, in the prefrontal cortex, might quell an addict’s insatiable urge to get high.
Gallimberti thought TMS might offer a practical way to do that. Our brains run on electrical impulses that zip among neurons with every thought and movement. Brain stimulation, which has been used for years to treat depression and migraines, taps that circuitry. The device is nothing but a coiled wire inside a wand. When electric current runs through it, the wand creates a magnetic pulse that alters electrical activity in the brain. Gallimberti thought repeated pulses might activate drug-damaged neural pathways, like a reboot on a frozen computer.
He and his partner, neurocognitive psychologist Alberto Terraneo, teamed up with Bonci to test the technique. They recruited a group of cocaine addicts: Sixteen underwent one month of brain stimulation while 13 received standard care, including medication for anxiety and depression. By the end of the trial, 11 people in the stimulation group, but only three in the other group, were drug free.
The investigators published their findings in the January 2016 issue of the journal European Neuropsychopharmacology. That prompted a flurry of publicity, which drew hundreds of cocaine users to the clinic. Perotti came in edgy and agitated. After his first session, he says, he felt calm. Soon he lost the desire for cocaine. It was still gone six months later. “It has been a complete change,” he says. “I feel a vitality and desire to live that I had not felt for a long time.”
It will take large, placebo-controlled trials to prove that the treatment works and the benefits last. The team plans to conduct further studies, and researchers around the world are testing brain stimulation to help people stop smoking, drinking, gambling, binge eating, and misusing opioids. “It’s so promising,” Bonci says. “Patients tell me, ‘Cocaine used to be part of who I am. Now it’s a distant thing that no longer controls me.’ ”