Addiction Research: All Brain and No Soul?
Addiction Research: All Brain and No Soul?
The American Society of Addiction Medicine made headlines two weeks ago when it released its new definition of addiction. Guess what? Addiction is a “primary, chronic disease of brain reward, motivation, memory and related circuitry”—which the popular media shorthanded as "a brain disorder, not bad behavior."
Unfortunately, this emphasis on neuroscience is not only not new, but may not serve to destigmatize addiction as intended, either. (And ASAM isn't the only player in the definition game: the next edition of the DSM, the psychiatric bible, will also include a new definition of addiction, which I will explore in a future column.)
The disease concept of addiction certainly isn't novel: the American Medical Association first defined alcoholism as a disease in 1956. Nor is the brain focus exactly groundbreaking. The former head of the National Institute on Drug Abuse during the Clinton administration, Alan Leshner, promoted the same idea throughout the '90s, saying, “Addiction is a disease because drugs change the brain.”
Unfortunately, all this narrowing in on the brain doesn't yet tell us much. And, while it is intended to reduce moral approbation, studies show that when people are told that something is a brain disorder, they tend to view it as less changeable and more hopeless. Stigma increases, rather than declines.
Another failing of the brain model is its oversomplicity: After all, every experience that we sense, consider and remember changes the brain, not just taking drugs. Looking at a skyscraper, reading a book, petting a kitten, eating a peach: none of these can be experienced without congruent brain changes. Otherwise sensation and memory would be impossible—or would be evidence of a “disease!”
All the “neuro” babble we hear about the Internet, porn, twitter—or drugs—“rewiring” our brains needs to be taken in this context.
The brain’s normal state is to become rewired by experience—otherwise, we couldn’t learn at all. Sensation requires brain changes to produce experience; learning requires brain changes in order to store memory. But no one worries about parents, teachers and lovers rewiring our brains—or at least, only in the context of abuse.
So why do we think about drugs so differently? Why do we see drug-related brain changes as an inherently pathological form of experience? In part, it’s because the only drug users we tend to hear from publicly are addicts.
Even though 80-85% of users of cocaine, heroin, methamphetamine and alcohol never become addicted, the stories in the media about drugs come overwhelmingly from the minority that do.
No one writes a memoir about trying meth once and finding it “meh.” Non-alcoholics don’t cherish the memory of their first drink in amber nostalgia; they usually don’t even remember it, let alone in enough detail to make it stand out in an Oprah appearance.
Because I cover drugs as a reporter, people frequently take me aside to share their own experiences. Often, they tell me about trying crack, heroin or OxyContin, just once. Then, seemingly expecting that I will have never heard such a story before, they confess that they thought it was so wonderful, they didn’t feel safe doing it again. And so they didn’t. Their self-discipline saved them.
But while I try not to be obnoxious, I don’t provide the praise they expect for displaying such self-control. Instead, I explain that this is actually a common choice—more common, in fact, than use leading to addiction. I discuss how the lack of drama in these types of stories and the fact that they don’t “send the right message” in anti-drug terms keeps the truth hidden.
As a result—and further prodded by a media that loves drug scares and politicians who use them to win votes—we hear almost exclusively about the aberrant experience of addiction in public narratives on drugs. Consequently, we think that’s what drugs do. This makes understanding addiction and what it means quite difficult.
Take the recent reports on brain-scan studies of people who use tanning beds. Headlines screamed: “Tanning Bed Users Show Brain Changes Like Addicts,” and "People Addicted to Tanning Just Like Drugs or Booze.”
However, as I pointed out recently on TIME.com: “Many of us clearly take risks to enjoy tanning, which is one potential sign of addiction. But saying that tanning is ‘addictive’ because the reward areas of people's brains light up in response to UV light is a little like saying we like sugar because it tastes sweet. It's a tautology. Anything that you perceive as enjoyable will activate the pleasure regions: if it didn't, it couldn't be experienced as pleasant.”
We need to know more than that someone has taken a drug that he likes. We need to know about the rest of his life, his social support, his mental illness, education, employment, as well as his values and sense of meaning.
These “pleasure” regions are all the rage these days. They were first discovered in research on rats. Attempting to enhance learning, researchers implanted electrodes into a brain region that they thought might be involved in motivation. One of the rats just loved visiting the corner of the cage where it would receive the stimulation. It would hang out there even when it wasn’t being stimulated.
The researchers realized that they had misplaced the electrode in that rat. It had landed in the center of the brain in a previously unidentified area: the nucleus accumbens. Since then, researchers have found that any experience of pleasure or desire—tanning, music, sex, sugar, salt or, yes, drugs—is linked with activity of the neurotransmitter dopamine in this region.
Unfortunately, this observation has been overgeneralized to suggest that any activation in this area indicates addiction. If that were true, we would all have to be will-less zombies addicted to everything that we had ever, even once, liked or wanted. But that’s not the case, even in addiction.
For example, some addicts have high levels of craving without relapsing, while other addicts have relapsed without high levels of craving. Simply showing activation of the nucleus accumbens or elevated stress hormones in response to seeing drug paraphernalia doesn’t prove that someone is an addict—or that they cannot control their behavior.
And calling activation of the nucleus accumbens or related regions “signs of addiction” also misses the point. These reward-, pleasure- and motivation-linked brain areas didn’t evolve so that people could become drug addicts. They are there to get us to eat, drink, stay safe, raise our kids and have sex as appropriate—and their activation signals nothing more than that the brain is having, or expecting to have, a pleasant experience.
So don’t be fooled by pretty brain pictures or accounts of studies claiming to “prove” that something is addictive. This work is helping us understand how pleasure and desire work—and how they may go awry. In particular, it suggests that addiction may indeed be a form of “overlearning” that wires these areas to find drugs too pleasurable and too desirable; to make them more attractive than any other experience.