In courtrooms around the country, judges are embracing 24/7 Sobriety, a science-backed approach to managing people addicted to alcohol who repeatedly drive drunk. Every morning and evening, defendants and convicts in the program must take a Breathalyzer test at a local police station. If they’re sober, they get an immediate reward: freedom. If not, they’re arrested on the spot and jailed overnight.

“It’s a modest penalty,” explains Keith Humphreys, a Stanford professor of psychiatry and behavioral sciences who helped popularize the program. “But unlike anything else, this is swift and certain, and that is perfect for a person who is addicted.”

The prospect of future rewards and punishments doesn’t much influence people whose brains have been changed by addiction. “We all have trouble thinking about the future,” says Humphreys. “We all spend money on our latte when we should be putting it into retirement.” But in addicted people, that human truth is vastly amplified. The 24/7 approach is about working with brains as they are, “thinking about the people who are addicted, who have reduced [self-] control and are very present-oriented.”

Humphreys didn’t start out interested in neuroscience. For two decades, he worked on public policy solutions to addiction. Then in 2015, Humphreys joined forces with two other Stanford professors, Robert Malenka and Brian Knutson, to create the NeuroChoice Initiative, an interdisciplinary collaboration among more than a dozen faculty members spanning departments from psychiatry and neurobiology to law and economics to electrical engineering. Their ultimate aim: to build a robust picture of how humans make choices, for their own good and to their detriment.





‘If it didn’t make you feel better, you wouldn’t pursue it. The mammalian nervous system evolved to tell us something.’





Their work, and the work of others at Stanford, is moving addiction science out of the lab and into society in the form of better diagnostics and treatment. Decoding the brain’s reward system also enables businesses to help—or harm—people tipping into compulsive behaviors, and it can help lawmakers create evidence-backed policies that better protect public health.

How Addiction Works

“What’s exciting about addiction,” says Malenka, PhD ’82, MS ’83, a professor of psychiatry and behavioral sciences, “is that, unlike a lot of other complex neuropsychiatric disorders like schizophrenia or bipolar disorder, we understand the pathophysiology. We actually know what causes addiction.”

At its core, addiction taps into an ancient reward circuitry in the brain. As humans evolved over the past 300,000 years, they needed something that would signal their most basic needs. That’s why food tastes good when you’re hungry. Water tastes good when you’re thirsty. Sex feels good, well, most of the time. “If it didn’t make you feel better, you wouldn’t pursue it,” Malenka explains. “The mammalian nervous system evolved to tell us something.” When exposed to a rewarding stimulus, certain parts of the brain respond by releasing dopamine, a chemical that transmits signals between neurons.

Over time, those bursts of dopamine teach the brain that something important is happening, and brain connectivity changes to make the behavior easier to repeat. As a result, habits form.

Drugs trigger large surges of dopamine, which reinforce the connections among the drug, the pleasure it produces and external cues from the environment. As these paths grow stronger, a person derives less pleasure from everyday activities. Compulsive behaviors involving gambling, pornography, sex or technology stimulate the same reward pathways and have a similar profile in the brain.

“That doesn’t mean the brain mechanisms are identical,” Malenka says, “but it does mean there is significant overlap in some of the circuits that are operating pathologically in these various forms of behavior—and it all has to do with the reward-system circuitry.”

Drugs affect the reward circuitry more strongly because they are introducing a foreign substance into the brain. “That’s why cocaine is addictive and broccoli isn’t—because there are receptors in the brain primed for cocaine,” Humphreys says.

Pleasurable activities tip into a dangerous zone when they become risky or prevent someone from engaging in a normal social, recreational or professional life. “People say, ‘I’m addicted to my smartphone,’ but central to the definition of addiction is harm,” Humphreys says. “So, I check my cell phone 100 times a day, but I never check it with my kids in the car—that’s not addiction.”

‘Ten or 15 years ago, I never had a patient seeking help for sex or gambling or video games. Now I see those patients on a weekly basis.’



Anna Lembke, MD ’95, medical director of addiction medicine at the School of Medicine and an associate professor of psychiatry and behavioral sciences, says she’s seeing more and more people struggle with behavioral addictions. “Ten or 15 years ago, I never had a patient seeking help for sex or gambling or video games. Now I see those patients on a weekly basis.”

One of the most challenging things about these types of addictions is they often come from a behavior that is healthy and adaptive, Lembke says, like eating or exercise. And when it comes to technology, it’s nearly impossible to live a modern life absent of screens and electronic communication. “I think it’s a whole new era,” Lembke says. “It’s really challenging. It’s severely debilitating to people.”

More Targeted Treatments

To treat someone grappling with an addictive behavior, Lembke uses the same approach as she would with alcohol. She advises a patient to abstain from the behavior for a month. This helps him end a compulsive cycle and reset his brain pathways. For example, if someone is addicted to video games, she’ll tell him to put away all devices, including his smartphone, which Lembke calls “the most portable and powerful conduit” to technology-related compulsions. The person should let others know he will be offline for this period of time. Work computers are typically OK, Lembke says, because most employees know that their employers monitor their internet use.

Initially, people trying to kick a habit experience all the signs and symptoms of withdrawal: depression, irritability and agitation. The good news is, if people abstain for a month, they usually feel better.

Then Lembke works with individuals to put barriers in place so that they engage in the behavior in moderation, or continue to abstain while receiving support. “It’s often the case that people can’t eliminate these things altogether—think of food, sex or technology,” she says. “So we discuss how to integrate the behavior back into your life without it causing harm.”

One patient with a gambling problem called a casino and placed himself on the list of banned clients. Another patient gave up listening to sports radio and reading about sports because those activities triggered his sports-gambling cravings. Lembke notes that both medication and therapy can help, too, as can anonymous mutual-help meetings, such as Gamblers Anonymous.

In the case of substance addictions, better diagnostics now enable scientists to use brain activity to predict who might need extra help in recovery. In a paper published December 28 in the medical journal JAMA Network Open, Knutson, PhD ’93, a professor of psychology and neuroscience and a NeuroChoice coordinator, assessed Veterans Affairs patients in treatment for the use of stimulants such as cocaine and methamphetamine.

“The problem with stimulant abuse,” Knutson says, “is that there is a huge rate of relapse”: about half the people in recovery. The usual measures of predicting who is at risk, such as asking people how severe their addiction is, are not very useful.

Knutson, postdoctoral researcher Kelly MacNiven, PhD ’15, and their colleagues scanned the brains of 36 veterans participating in a four-week residential treatment program for stimulant-use disorders, along with 40 healthy people recruited from the surrounding community. Inside the MRI scanner, participants looked at a series of images of things like food, office supplies, and drugs and drug paraphernalia. After the patients left treatment, the research team followed up at one, three and six months with interviews and, in some cases, drug tests to find out whether any of the patients had relapsed.

When researchers looked at fMRI images of the participants’ brains, they found a strong correlation between the activation of specific brain regions and the likelihood of relapse. Of particular interest was the nucleus accumbens, a region near the base of the brain that releases chemicals such as dopamine when triggered by pleasurable experiences. If the nucleus accumbens lit up when the participant viewed images of drugs or drug paraphernalia, he or she would be likely to relapse within three months. Using only activity in the nucleus accumbens, the team could correctly identify 77 percent of the patients who would relapse.

In this study, Knutson says, brain scans did a better job of predicting relapse than do typical assessments, such as asking people what their level of drug craving is. Still, it’s too early to say whether brain predictors will be widely applicable or useful in clinical settings.

Another, more radical idea Knutson has been pursuing is controlling the brain signal itself. Maybe people who know that their nucleus accumbens lights up when they see drug images can be taught to calm that part of their brain. Or perhaps clinicians could stimulate the brain from the outside with magnets, an approach called transcranial magnetic stimulation that’s being tested as a potential treatment for drug addiction. “One can imagine a lot of possibilities,” Knutson says. “We don’t have a preference, but we want to do something that has both short- and long-term effects in the brain.”

My Boss the Smartphone

The word addiction comes from addicere, a Latin word meaning “to enslave.” So when we throw around the word, “what we are saying is that we are powerless; we have no choice in our behaviors,” says Nir Eyal, MBA ’08, an entrepreneur and the author of two books that discuss our relationship with our devices, Hooked: How to Build Habit-Forming Products and the forthcoming Indistractable.

Eyal says only a small fraction of people use technology obsessively. A 2014 meta-analysis of 31 nations published in the journal Cyberpsychology, Behavior, and Social Networking estimates internet addiction to be about 6 percent. For the rest of us, Eyal says, it’s simply overuse: “Humans like to escape reality. That’s part of our nature. Whether it’s storytelling, drugs or phones—this is just the latest medium.”

Still, Eyal says, tech companies have an obligation to help their heaviest users cut back, in part because they collect enough data to know exactly who those users are. “Companies need to make a use and abuse policy,” he says. For example, they could encourage frequent users to dial back after a certain number of hours, or send them resources to help. “If they wanted to help bona fide addicts, they could do so,” Eyal says. Kids, he adds, should be a priority.

Design ethicists such as Tristan Harris, ’06, argue that smartphones should display gray icons on the home screen by default, instead of colorful ones. Mobile device makers could also enable users to create “zones” that set which apps they want to see at different times of the day, allowing for better control over what vies for their attention. In a 2016 TEDx talk in Brussels, Harris suggested that technology company executives prioritize a new metric in their design decisions: net positive contribution to human life. “We have to demand this new kind of technology,” he said.

The Nintendo Wii, released in 2006, displayed a message that said (in essence): You played a lot today; it’s time to go outside. That approach is coming around again, at least at some companies. On Stack Overflow, the largest Q&A site for computer programmers, users gain points on the platform through engagement. After someone uses the site 20 hours in a week, the program stops granting points. “The founder did that because he wanted to improve lives,” Eyal says.

In China, under pressure from the government, video game publisher Tencent limited playing time for its most popular game, Honour of Kings, to two hours per day for players under 18 and one hour per day for players under 12. Last year, the company announced it would expand the verification system enforcing that policy to all its titles.



How to Control Your Phone Habit Even if only a small percentage of people have an addiction to technology, most of us overuse it and are distracted by it. Here are some ways to be more mindful about how we use our devices: 1 Install and use screen-time control and apps like Freedom, which limit access for a specific duration of time. 2 Ask yourself “why?” each time you reach for your smartphone. 3 Try a digital detox in which you put away your smartphone for a month and pull out an old basic phone for calls and texts. 4 Set your home screen to black and white to reduce the allure of colorful pictures. 5 Start with something small, like leaving your phone at your desk when going to lunch with co-workers. 6 Charge your device away from where you sleep, to avoid diving into apps before bed and first thing in the morning. 7 Spring-clean your apps. Don’t keep anything that you don’t use on your phone.

Elias Aboujaoude, a clinical professor of psychiatry and behavioral sciences at Stanford, was one of the first researchers to study problematic internet use back in 2004. He says that, paradoxically, new technology may be the best way to help people control their use of tech. “There isn’t a single form of therapy or medication that has been proven as extremely effective in treating technology addiction, so why not consider tech-mediated therapy for tech addiction?” says Aboujaoude, MA ’98, MD ’98. While browser and app settings that limit use have goals similar to those of traditional treatments, they may be more efficient, scalable and affordable.

Both Apple and Google, two of the biggest smartphone developers, created dashboards last year that inform people how they’re spending time on their devices, and each offers a tool for setting screen-time limits. Apple also now enables parents to remotely manage their kids’ device usage.

Peering into the Future

When Humphreys gives talks to law enforcement officers and jurists, he often recalls the days before neuroscience entered his research. “I could tell police and judges how addicted offenders cycled through the criminal justice system, but I couldn’t tell them why,” he recalls. “Neuroscience gave me a mechanism and a language that they and I understood.” He’d like to help build a science-based future by dispelling one pernicious idea: that addiction is just substance abuse. “Just because an addicted person hasn’t been able to drink, they still have some enduring neuroadaptational changes to the brain,” Humphreys explains. “It’s not a question of ‘Can we teach the person a lesson?’ It’s about their brain.”

Humphreys now advocates for insurance programs like Medicaid and Medicare to cover opioid agonists—long-acting drugs that reduce cravings and restore the ability to function—for people addicted to opioids. “I want to help people see the rational, intelligent things we can do to help people struggling with addiction, help society and avoid filling up prisons,” he adds. “We have all the science, but it’s not going to help anyone if it sits here at Stanford.”

Knutson predicts that over the next 10 to 20 years, a new kind of science will emerge that uses brain activity to do “neuroforecasting,” which uses the aggregate activity of many brains to predict the choices people are likely to make. His lab examines how choices are made—for example, why don’t most people save enough for the future? “We’re in a watershed moment where many scientists but also policymakers are interested in solutions to problems that are based not on convenience but on scientific evidence.”

Katharine Gammon is a science writer based in Santa Monica, Calif.