The Craving Cycle

A former addict turned neuroscientist, Marc Lewis describes what happens in the brain when addiction sets in, and how Buddhist psychology helps explain it.


About 25 years after quitting drugs, I decided to write a book about the experience of addiction and the brain processes underlying it. Around my desk I stacked 20 volumes of personal notes from my mid- to late 20s. They told, in relentless detail, of my growing attachment to opiates, periods of depression that led to intense craving and compulsive thinking, and increasingly desperate schemes for acquiring drugs. They told of my crazy misadventures: stealing morphine from the labs I worked in, breaking into pharmacies at night, violating every moral standard I lived by. And they told of my eventual expulsion from grad school and a seemingly endless cycle of elation, loss, and self-hatred.

I finally did stop. I completed my PhD. I became a professor in developmental psychology and neuroscience. I had amassed thousands of articles on the emotional brain, self-regulation, and the neurobiology of addiction. I knew what addiction felt like, and what it looked like on a brain scan. The trick was to put these pieces together.

Over the same period of time, Mind & Life pioneered a new approach to the study of human capacities, based on the integration of subjective accounts with scientific experimentation. The idea was to examine human experience from the inside and the outside at the same time. That’s just what I wanted to do in my book. I also wanted to show how miserable we can make ourselves when we look for answers in all the wrong places. And how self-destructive habits develop, quite naturally, along the fault lines of our biology.

Whenever we pursue attractive goals, a neurochemical called dopamine is released. Dopamine is absorbed by brain structures responsible for narrowed attention, effortful action, and above all, desire—the visceral thrust that motivates goal seeking. When addiction sets in—whether to drugs, booze, cigarettes, sex, gambling, food, or something else—what starts out as an episode of pleasure (or relief) begins to control the dopamine pump. Soon, dopamine release is determined by the anticipation of getting more, and the overlapping neural networks of desire and intentional action are increasingly tuned to that singular goal. Those networks also become less and less sensitive to other goals. It feels tremendously exciting when you think you’re about to get whatever “it” is. But if you can’t find it, or it’s not enough, or you’ve just run out—or your partner threatens to leave you the next time you indulge—you suffer. The craving intensifies.

As this cycle repeats, areas of the cortex that represent what’s important and valuable become rewired. More and more synapses are devoted to “it”: thinking, reminiscing, planning, imagining—constructing intricate strategies for getting.

At the same time, cortical regions responsible for cognitive control and self-monitoring become less effective—partly because they wear themselves out like a car revving its motor way too high for way too long—and partly because they lose their connection with whatever one is trying to control. But here’s the kicker: Overvaluation of a single substance or activity never actually satisfies. At least not for long. After every cycle of wanting, getting, and loss, there is emptiness. Disappointment. A sense of betrayal. And that makes one all the more desperate for relief.

My saga stretched from being an addict to studying addiction as a scientist. I wrote my book; it did well. I started getting invited to talk about addiction to scientists, clinicians, and addicts themselves. I was interviewed on television and radio; I was featured in newspaper and magazine articles. It was a great ride. But then it took a turn I never would have expected.

One day last winter, I got an email inviting me to attend a five-day meeting with the Dalai Lama this fall, along with seven other academics, scientists, and contemplatives, at his residence in Dharamsala. The theme of the meeting was craving and addiction. Hey, I thought, that’s something I know about! Yet it seemed I was dreaming—this was too good to be true.

For the last few months, to prepare for this meeting, I’ve been trying to think like a Buddhist. And what strikes me most is that the Buddhist perspective on personal suffering—based as it is on desire and attachment—captures addiction surprisingly well. So well, in fact, that addiction comes off looking like a fundamental aspect of the human condition.

Buddhism sees personal pursuit and attachment as a cycle—a self-perpetuating cycle—in which many interacting elements contribute to ongoing suffering . What Buddhists describe as the lynchpin of human suffering, the thing that keeps us mired in our attachments, is exactly what keeps addicts addicted. The culprit is craving and its relentless link to grasping. We see something attractive outside ourselves—something that promises to fill the inner emptiness—and we crave it. Then we reach for it, grasp it, and despite the pleasure or relief we might achieve temporarily, it’s never enough. We crave more. That’s what keeps the wheel going round.

Whether the goal is success, material comfort, prestige (the more respectable human pursuits)—or whether it’s heroin, cocaine, booze, or porn—hardly seems to matter. Either way, we believe we’ve locked our sights on an antidote to uncertainty, a guarantee of completeness, when in fact we never become complete by chasing after what we don’t have. And, most incredibly, the pursuit itself becomes the condition for more suffering because we inevitably come up empty, disappointed, and betrayed by our own desires.

That sounds a lot like addiction to me. Yet the Buddhists talk about this as normal seeking and suffering. Isn’t addiction something abnormal? What about all those brain changes? To most scientists and practitioners (e.g. physicians, mental health experts, and addiction counselors), those brain changes suggest that addiction is a disease, an unnatural state. But a Buddhist perspective might cast it quite differently—as a particularly onerous outcome of a very normal process, a sadly normal process: our continuing attempt to seek fulfillment outside ourselves.

But if such a process is normal, why would the brain change?

It turns out that the brain is designed to change. Every advance in child and adolescent development requires the brain to change. In fact, the condensation of value and meaning in adolescence corresponds with the loss of about 30 percent of the synapses in some regions of the cortex. Normal development, much like addiction, involves a lasting commitment to a small set of goals: I’m going to make money; I’m going to live in a secure neighborhood; I’m going to find a life partner. That commitment involves the formation and consolidation of some neural networks at the expense of others.

Indeed, every episode of learning, whether to play a violin, move in a wheelchair, or see with your fingers after going blind, requires the growth of new synaptic networks. These cortical changes ride on waves of dopamine, both in normal development and in addiction. Gouts of dopamine, with its potency to narrow attention and grow synapses, are highly familiar to lovers and learners alike. That palpable lurch for sex, admiration, or knowledge is always dopamine driven. In fact, the brains of starving animals are transformed by dopamine because, as with addiction, there is just one goal worth pursuing. Studies have shown that successful politicians achieve dopamine levels that would make an addict swoon. The brain has evolved to connect desire and acquisition, wanting and getting, and that connection depends on the tuning of synaptic networks to a narrow range of goals with the help of dopamine.

For both normal development and addiction, desire acts as a carving tool, collapsing neural flexibility in favor of fixed goals. That’s why our understanding of addiction may benefit more from a Buddhist-style perspective on normal development than the disease model favored by Western science and medicine.

The Buddhist perspective offers an advantage, too, when it comes to recovery: an emphasis on the value of mindfulness and self-control to free ourselves from unnecessary attachments.

Consider a provocative experiment recently published in PLOS ONE, a prominent science journal. While it’s well known that addiction causes thinning in certain regions of the cortex—believed to reflect a loss of synapses—this study found increasing synaptic thickness in cocaine addicts who had abstained for several months. In fact, the longer the period of abstention, the greater the growth. Contrary to expectations, the new growth wasn’t simply a reversal of what was lost, like a pruned bush growing back its leaves. Rather, synaptic growth was observed in new areas—areas underlying self-reflection, self-direction, and self-control. Most surprising, this growth surpassed levels reached by “normal” (never addicted) people after a period of roughly eight months, indicating the emergence of more advanced mental skills.

If these results are replicated, they’ll provide solid evidence that recovery, like addiction, is a developmental process, which may benefit from the advanced cognitive capacities facilitated by mindfulness training.

Based on studies such as these—and filling in the blanks with subjective accounts—addicts, scientists, and contemplatives have a lot to learn from each other. After all, addicts and Buddhists—all of us—make use of the same brain, with its vulnerabilities and strengths. It makes sense that the brain changes underlying suffering and healing have much in common, whatever their source.

MARC LEWIS, PhD, is a developmental neuroscientist and professor of developmental psychology, recently at the University of Toronto (where he taught and conducted research from 1989-2010), and presently at Radboud University in the Netherlands. He is the author or co-author of more than 50 journal publications in psychology and neuroscience and the book Memoirs of an Addicted Brain, which blends his life story concerning addiction with a user-friendly account of how drugs affect the brain and how addiction alters neural chemistry and structure. He recently presented his work at Mind & Life XXVII in Dharamsala, India.

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