Irresistible

by Adam Alter

  The answer, it turned out, had been uncovered more than a decade earlier in a U.S. neuroscience lab some eight thousand miles away.

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  Great scientists make their discoveries using two distinct approaches: tinkering and revolutionizing. Tinkering slowly wears down a problem, like water erodes rock, whereas in revolutions, a great thinker sees what no one else can. If the engineer Peter Milner was a tinkerer, the psychologist James Olds was a revolutionary. Together they made a superb team. In the early 1950s, in a small basement lab filled with caged rats and electrical equipment at Montreal’s McGill University, Olds and Milner ran one of the most famous addiction experiments of all time. What made the experiment so remarkable was that it wasn’t actually designed to reshape our understanding of addiction.

  In fact, it might have gone unnoticed if Olds had done his job properly.

  Olds and Milner met at Montreal’s McGill University in the early 1950s. In many ways they were opposites. Milner’s biggest strength was his technical know-how. He knew all there was to know about rat brains and electrical currents. Olds, on the other hand, lacked experience but overflowed with big ideas. Young researchers floated in and out of Olds’ lab, drawn to his flair and talent for spotting the next big thing. Bob Wurtz, Olds’ first graduate student in the late 1950s, knew Olds and Milner well. According to Wurtz, “Olds didn’t know the front of the rat from the back of the rat, and Milner’s first job was to educate Olds on rat physiology.” But what Olds lacked in technical prowess, he more than made up for with brio and vision. “Jim was a very aggressive scientist,” says Wurtz. “He believed in serendipity—if you see something interesting, you drop everything else. Whenever he and Milner stumbled on something newsworthy, Jim would deal with the media while Milner continued working in the lab.”

  Gary Aston-Jones, who also studied with Olds, remembered him the same way. “Olds was focused on big questions. He was always more conceptually driven than technically driven. When we were trying to understand how a fruit fly could learn about the world, Olds dropped to his hands and knees, crawled around on the floor, and pretended to be a fly.” Milner would never have approached the problem that way. Aryeh Routtenberg, a third student who worked with Olds, explained that “Milner was sort of like the other face of Olds. He was quiet, humble, and self-effacing, while Olds would proclaim ‘we’ve made a big discovery!’”

  For decades, experts had assumed that drug addicts—laudanum lushes, poppy tea drinkers, and opiate addicts—were predisposed to the condition, somehow wired incorrectly. Olds and Milner were some of the first researchers to turn that idea on its head—to suggest that, perhaps, under the right circumstances, we could all become addicts.

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  Their biggest discovery began modestly. Olds and Milner were trying to show that rats would run to the far end of their cages whenever an electric current zapped their tiny brains. The researchers implanted a small probe, which delivered a burst of electric current to each rat’s brain when the rat pressed a metal bar. To their surprise, instead of retreating, Rat No. 34 stubbornly scampered across his cage and pressed the bar over and over again. Rather than fearing the shocks as many other rats had done earlier, this rat hunted them down. The experimenters looked on as Rat No. 34 pushed the bar more than seven thousand times in twelve hours: once every five seconds without rest. Like an ultramarathon runner who deliriously refuses to stop for sustenance, the rat ignored a small trough of water and a tray of pellets. Sadly, he had eyes only for the bar. Twelve hours after the experiment began, Rat No. 34 was dead from exhaustion.

  At first, Olds and Milner were confused. If every other rat avoided the shocks, why would Rat No. 34 do the opposite? Perhaps there was something wrong with his brain. Milner was ready to try the experiment with a different rat when Olds made a bold suggestion. Olds had once crawled around to imagine life as a fruit fly, and now he tried his hand at reading the mind of a rat. Considering Rat No. 34’s behavior carefully, he became convinced that the rat was enjoying the shocks. It wasn’t that he was seeking out pain, but rather that the shocks felt good. “The genius of Jim Olds was that he was open-minded enough and crazy enough to think that the animal liked being shocked,” Aston-Jones said. “At the time, no one imagined that electrical stimulation in the brain could be pleasurable, but Olds was crazy enough to think the animal was having a good time.”

  So Olds investigated. He removed the probe from the rat’s brain and noticed that it was bent. “Olds had been aiming for the mid-brain, but the probe bent into the rat’s septum,” says Aston-Jones. A fraction of an inch made all the difference between delight and discomfort. Olds took to calling this area of the brain the “pleasure center,” a simplistic name that nonetheless captures the euphoria that rats—and dogs, goats, monkeys, and even people—feel when the area is stimulated. Some years later, when neuroscientist Robert Heath inserted an electrode into a depressed woman’s pleasure center, she began to giggle. He asked why she was laughing, and though she couldn’t offer an explanation, she told him that she felt happy for the first time in as long as she could remember. As soon as Heath removed the probe, the patient’s smile disappeared. She was depressed again—and worse, she now knew what it felt like to be happy. She wanted more than anything for the probe to remain implanted, delivering regular shocks like a small hedonic pacemaker. Like Olds and Milner before him, Heath had shown how addictive euphoria could be.

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  After the demise of Rat No. 34, Olds and Milner found the same addictive behavior when they stimulated the pleasure center of other rats. Those rats, too, ignored food and water while they pushed the little bar over and over again. Aryeh Routtenberg worked on some of these follow-up experiments, and he recalls that the rats behaved like addicts. The bar-pushing rats were no different from rats that had addictive substances injected directly into their brains. “We threw all sorts of feel-good drugs at the animals—amphetamines, chlorpromazine, monoamine oxidase inhibitors—and they behaved just like the self-stimulating rats.” Routtenberg remembers an experiment that showed the power of the pleasure center:

  One of the nice things about being a professor is that you can study whatever you like. I wanted to see what would happen if I made the bar-pressing animals drunk. I injected the alcoholic equivalent of a three-martini lunch into several rats, who just fell over. We lifted them up—as you’d drag a drunkard from the bar—and we led them over to the small metal bar. We laid them down so their heads brushed against the bar, which delivered a shock to their brains. In no time, these rats started pressing the bar over and over again. They were catatonic just a minute ago, but now they looked absolutely normal! After ten or fifteen minutes, we disabled the shocks, and the rats fell back into a stupor.

  That wasn’t the only reason why the researchers saw the rats as tiny addicts. They showed the same restlessness that human drug addicts show between hits. When the researchers prevented the rats from shocking themselves more than once every few minutes, the rats took to drinking lots of water to pass the time. “The minute the reward stopped, they’d start drinking like crazy,” recalls Routtenberg. “I’d come back between experimental sessions and they were sitting there, completely bloated! It’s like they were doing something—anything—to pass the time. The reward was so great that they would need to find a way to pass the time until the next reward was available.”

  Word of the experiments got out, and the researchers began to hear rumors. “We heard that the military was training goats,” Bob Wurtz recalls. “They would guide the goats to bring ammunition to soldiers, or even to carry bombs to the enemy.” The soldiers could encourage the goats to walk in a specific direction by shocking or withholding shocks from the pleasure center. The research influenced how experts like Wurtz, Aston-Jones, and Routtenberg understood addiction. Olds and Milner originally believed that Rat No. 34 was predisposed to be an addict. They assumed that a problem with his internal wiring h
ad driven him to place electric stimulation above all else—even food, water, and ultimately life. But at Olds’ urging, they realized that there was nothing wrong with Rat No. 34. He wasn’t an addict by nature. He was just an unfortunate rat that happened to be in the wrong place at the wrong time.

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  This is one of the great lessons from Olds and Milner’s experiment. Rat No. 34 behaved like an incurable addict but that didn’t mean there was something wrong with his brain. Like the Vietnam G.I.s, he was a victim of circumstance. He was simply responding as any rat would have done when a probe delivered shocks to his pleasure center.

  Routtenberg wondered if this might tell us something about addiction in humans. But perhaps anyone could descend into oblivion like Rat No. 34. “We started to think of addiction as a form of learning. You can think of addiction as part of memory,” says Routtenberg. Addicts had simply learned to link a particular behavior with an appealing outcome. For Rat No. 34, this was stimulation of his pleasure center; for a heroin addict, the flush of pleasure from a fresh hit.

  To measure the link between addiction and memory, Routtenberg visited the local pet store and bought a squirrel monkey named Cleopatra. Ethics boards weren’t as strict as they are now. “I had my own lab room, so I could do whatever I wanted. I operated on her and put electrodes in the reward systems of her brain. This had never been done before with a monkey.” Routtenberg placed Cleopatra in a cage in front of two metal bars. The first sent an electrical current to her pleasure center, and the second released a fresh supply of food. At first Cleopatra pushed the bars randomly, but very quickly she began to behave like Rat No. 34, ignoring the food bar and pressing the electric shock bar over and over again. Olds saw what Routtenberg had done, and he was delighted. “He came down to the lab with a friend, who was a big-time researcher at Johns Hopkins, and showed him what Cleopatra was doing,” Routtenberg says. “It was one of the proudest days of my life.” Later, Routtenberg removed Cleopatra from the cage for hours or even days. Outside the cage, she detoxed, becoming the same healthy monkey she had been when she first arrived at the lab. But as soon as Routtenberg returned her to the cage, she would frantically begin pressing the bar again. Even when the bar was removed from the cage, she would stand where it had once been. As Routtenberg guessed, Cleopatra’s addiction had left a powerful imprint in her long-term memory.

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  Jim Olds’ lab held the solution to Lee Robins’ conundrum. The reason why her Vietnam vets escaped their heroin addictions was because they had escaped the circumstance that ensnared them. That was the case for Cleopatra, Aryeh Routtenberg’s squirrel monkey, who was every bit the addict inside her cage. She pounded the metal bar that delivered shocks to her pleasure center over and over again. She ignored her food and water. This cage was to Cleopatra what Vietnam was to the bored G.I.s who developed a taste for heroin. Cleopatra was healthy until she joined the lab. When Routtenberg eventually removed her from the cage, she became healthy again. But when she sat inside her cage, the addiction returned with a vengeance.

  Cleopatra returned to her cage, but few of the G.I.s ever returned to Vietnam. They arrived home to a completely different life. There was no trace of the jungle; the steamy summers in Saigon; the rattle of gunfire, or the chop of helicopter blades. Instead, they went grocery shopping, they returned to work, they endured the monotony of suburbia, and enjoyed the pleasures of home-cooked meals. Both Cleopatra and the soldiers showed that Routtenberg was right: addiction embeds itself in memory. For Cleopatra, the cage was a trigger. It transported her back to the time when she had been an addict, and she couldn’t help falling back on old habits. The lucky Vietnam vets never confronted those memories, because once they left Vietnam they escaped the cues that went along with the act of shooting up.

  This is why most heroin users struggle to stay clean. Like Cleopatra, they return to the scene of the crime over and over again. They see friends who remind them of a time when they were addicts; they live in the same homes; they walk through the same neighborhoods. Nothing changes once they’re clean, except the fact that instead of giving in to the addiction, they’re resisting it every day. This is why the temptation is so great. What else are they supposed to do when every sight, smell, and sound rekindles the moment of bliss that follows a hit?

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  Isaac Vaisberg, a former gaming addict, knows the dangers of returning to the scene of the crime. Nothing marks Isaac as a natural candidate for addiction. He was born in Venezuela in 1992 to a wonderfully supportive mom and an overworked but attentive dad. When Isaac was a boy, his parents divorced and he moved to Miami with his mom. His dad remained in Venezuela, but the two talked often, and Isaac visited when he wasn’t in school. His grades were stellar, rarely dropping below an A. At the end of his junior year of high school, he scored 2200 out of a possible 2400 on the SATs, which placed him in the top 1 percent of all students in the United States. He was admitted to Worcester Academy, one of the country’s most competitive boarding schools, not too far from Boston, and later to American University in Washington, D.C. Isaac wasn’t just a scholar—he was also an athlete. Worcester granted him a football scholarship, and he arrived in great physical shape, ready to play as a first-string linebacker.

  Unfortunately, that’s only half the story. Isaac was lonely. “My parents got divorced when I was very young, and I ended up ping-ponging between the United States and Venezuela. Because of that ping-ponging, I was adept at forming new relationships, but not very good at forming deep relationships.” Instead, he found friends online.

  When Isaac was fourteen, he started playing World of Warcraft. WoW is addictive for a number of reasons, but Isaac found the game’s social dimension irresistible. Like many players, he joined a guild, a small band of players who share resources and chat regularly in guild-specific chat rooms. His guild-mates became his closest friends, and their friendship ultimately came to stand in for the meaningful relationships he lacked in the offline world.

  Isaac’s first dangerous binge began during his junior year in high school. “I had picked up and dropped World of Warcraft many times, but this time it became my sole means of socializing and my sole release. I got a small dopamine hit every night, and it helped me overcome my anxieties.” He stopped sleeping, his grades plummeted, and he became physically sick when his mother insisted he go to school. “I would flip out and have panic attacks. Getting in the car in the morning I’d feel nauseated. The second I knew I didn’t have to go to school, these symptoms went away.” Isaac ultimately recovered after this first binge, and by the end of that school year he was doing so well that he aced his SATs.

  Isaac’s second binge began a couple of months into his time at Worcester Academy. Left in his dorm room without supervision, he rejoined his old guild and rekindled the online friendships he’d formed the year before. Soon it became an obsession again. “When I arrived at Worcester Academy, I weighed about one-ninety-five. I was fit and playing football. By the end of the first semester, I weighed about two-thirty-five. I lost a significant amount of hair on my head, quit the football team, and had Cs across the board.” Isaac was resilient, though. He managed to complete his senior year and gain acceptance to American University. At this point he still believed his binges were flukes. He wasn’t concerned that his addiction might follow him to college.

  His first semester at American was a success—he aced his classes and remained fit and healthy. In his second semester, though, he became stressed. He decided to “play just a bit” of WoW as a release, and ultimately failed his second semester classes. Isaac’s transcript was a roller coaster of As and Fs, and his mom was so worried that she arrived unannounced and presented him with a pamphlet for the reSTART addiction recovery center, located just outside Seattle. He agreed to enroll in an inpatient program, but only after logging in to his WoW account to tell his guild-mates that he’d be offline for a while.

  reSTART is the
world’s first gaming and Internet addiction treatment center. Its founders recognize that Internet use differs from substance addiction, because it’s almost impossible to return to society without using the Internet. You can hold a job, pay your bills, and communicate without using drugs and alcohol, but not without using the Internet. Echoing the green movement, the center therefore aims to teach patients how to use the Internet “sustainably,” rather than encouraging them to avoid it altogether.

  Isaac began his six-week program with enthusiasm, making friends, painting, hiking the spectacular trails around the center, and regaining his strength at its gym. He formed close bonds with some of the mentors, who told him that WoW had given him an illusion of control over his life. Outside the game his world had continued to crumble, but that seemed to matter less and less as he conquered one WoW quest after another. Despite making good progress, at times he felt frustrated. Though reSTART had helped, Isaac saw his time there as a roadblock that distracted him from finishing college and moving on to a healthier, self-sufficient phase of his life. He couldn’t really be “better” until he settled back into the real world. Though he went as far as buying an airline ticket to D.C. online, he ultimately stayed for the full six weeks.