Drug Craving, or How to Be Your Own Worst Enemy

Plus the disease model, warts and all.

Bielefeld, Germany—

The second in an irregular series of posts about a recent conference, Neuroplasticity in Substance Addiction and Recovery: From Genes to Culture and Back Again. The conference, held at the Center for Interdisciplinary Research (ZiF) at Bielefeld University, drew neuroscientists, historians, psychologists, philosophers, and even a freelance science journalist or two, coming in from Germany, the U.S., The Netherlands, the UK, Finland, France, Italy, Australia, and elsewhere. The organizing idea was to focus on how changes in the brain impact addiction and recovery, and what that says about the interaction of genes and culture. The conference co-organizers were Jason Clark and Saskia Nagel of the Institute of Cognitive Science at the University of Osnabrück, Germany.  Part One is here.

Marc Lewis, a developmental neuroscientist who is currently professor of human development and applied psychology at Radboud University in The Netherlands, and who spent five days discussing addiction with the Dalai Lama and a small group of scientists, scholars, and addiction specialists in Dharamsala, India, last year, was a late but welcome addition to the speaker list at the conference.

Author of Memoirs of an Addicted Brain, and a self-confessed “drug addict turned neuroscientist,” Dr. Lewis always brings a thought-provoking dual perspective to his work on addiction. (See my review of his book here.) He also blogs here.

In Bielefeld, Dr. Lewis offered up a wide-ranging view of what addiction is and is not, linking neuroscience, psychology, and Buddhism in the process. 

Craving is “the one condition all addicts agree is their worst enemy,” Lewis said. “This is one place where science and subjectivity have to come together. Scientists need to focus on this, because addicts are completely unanimous about it. This is the enemy. It’s not physical withdrawal symptoms, it’s not relief. It is craving.”

Buddhism teaches that “craving is the fundamental engine of personality development,” Lewis said. “It’s what keeps us going around and around.” But if you don’t much like the notion of the wheel of reincarnation, Lewis suggested, then you can contemplate “the cyclical nature of how we repeat patterns in life that lead to suffering.”

“Craving is such an unpleasant state, that after a while, you end up doing it, you get the drugs. I did opiates, and I would spend hours and hours trying to sit on my hands, trying to watch something on TV, trying to go for a walk, and finally, there’s this thing that keeps rising in the background, and it doesn’t go away. It was a constantly growing tension, an anxiety and discomfort, that came from very deep down. You spend most of your energy trying to hold this thing at bay, and according to the ego depletion literature, you can’t do that for very long. These cognitive control centers just give up. They are limited resources.”

Craving is not a steady state. It grows. “Neuroscience helps us understanding why craving is so nasty.” Enter “delay discounting,” a term from behavioral economics used by several speakers during the conference. Delay discounting is the proposition that the perceived value of something rises steeply as the reward gets closer in time. A variation of this idea is seen in the classic marshmallow test for children: One marshmallow now, or two if you wait until later?

“Craving traps you in delay discounting,” said Lewis. “Immediate reward is worth more than imagined future happiness. The job of dopamine in the striatum is to increase the attractiveness or value of one goal, and to reduce the attractiveness and value of all the other goals. This is a brain that is well designed for addiction. You get tons of dopamine rising up in anticipation of reward. So you’re really stuck in the immediate. At which point you’ve effectively lost contact with the rest of your life. In the narrative of who you are, you can’t even include next week, or the next morning.”

Nonetheless, Lewis finds serious problems with the standard disease model of addiction, as championed by NIDA’s Nora Volkow and other in the NIH, however brain-based he may be. As a developmental neuroscientist, Lewis is predisposed to viewing the brain as a locus of change by definition. “The disease model uses brain change as a foundational premise. But brains change with development, anyway. And in fact, brains are designed to change.”

Any proper model of addiction, he insisted, has to correspond with what we know about brain change. “But it also has to correspond with addicts’ experiences. I was a drug addict from about age 25 to 30. I was in really bad shape. And now I talk with a lot of drug addicts, and one of the things that I keep hearing is that scientists and clinicians don’t really know what they’re doing—they don’t know where to go with it. They know that addiction is really nasty, but they don’t know what it’s like, unless they’ve been there.”

Lewis offered a view of addiction that shifts the semantic focus from disease to development. The drug is not the culprit. By reconceptualizing addiction as a developmental disorder, he suggested, we can move the debate forward into the world, where the action is:

Addiction results from accelerated learning, the acquisition of thought patterns that rapidly self-perpetuate because of the brain’s tendency to become sensitized to highly attractive rewards. This is a developmental process, accelerated by a neurochemical feedback loop that is particular to strong attractions. Like other developmental outcomes, addiction isn’t easy to reverse, because it’s based on synaptic restructuring. Like other developmental outcomes, it arises from neural plasticity, and uses it up at the same time.

And the mechanisms responsible are the same ones responsible for many things that involve desire, learning, reward seeking, and compulsive behavior—including the so-called behavioral addictions like overeating and compulsive sex. However, “the severe consequences of addiction don’t make it a disease, any more than the consequences of violence make violence a disease.”

In an email exchange after the conference, I followed up with Dr. Lewis on some of these matters, and he sent me the following additional thoughts on the “diseasing” of addiction:

Proponents of the disease model argue that addiction changes the brain. And they're right: it does. But the brain changes anyway, at every level, from gene expression, to cell density, to the size and shape of the cortex itself. Of course, neuroscientists who subscribe to the disease model must know that brains change over development. Their take on pathological brain change would have to be very specific in order to be convincing. For example, they would have to show that the kind (or extent or location) of brain change characteristic of addiction is nothing like that observed in normal learning and development. But this they cannot do. The kind of brain changes seen in addiction also show up when people take up rock collecting, fall in love, learn how to cook, or become obsessed with their appearance. The brain contains only a few major traffic routes for learning and goal seeking. And, like the main streets of a busy city, they are often under construction.  Brain disease may be a useful metaphor for how addiction seems, but it's not a valid explanation for how it actually works.

What is This Thing Called Neuroplasticity?

And how does it impact addiction and recovery?

Bielefeld, Germany—

The first in an irregular series of posts about a recent conference, Neuroplasticity in Substance Addiction and Recovery: From Genes to Culture and Back Again. The conference, held at the Center for Interdisciplinary Research (ZiF) at Bielefeld University, drew neuroscientists, historians, psychologists, philosophers, and even a freelance science journalist or two, coming in from Germany, the U.S., The Netherlands, the UK, Finland, France, Italy, Australia, and elsewhere. The organizing idea was to focus on how changes in the brain impact addiction and recovery, and what that says about the interaction of genes and culture. The conference co-organizers were Jason Clark and Saskia Nagel of the Institute of Cognitive Science at the University of Osnabrück, Germany.

One of the stated missions of the conference at Bielefeld’s Center for Interdisciplinary Research was to confront the leaky battleship called the disease model of addiction. Is it the name that needs changing, or the entire concept? Is addiction “hardwired,” or do things like learning and memory and choice and environmental circumstance play commanding roles that have been lost in the excitement over the latest fMRI scan?

What exactly is this neuroplasticity the conference was investigating? From a technical point of view, it refers to the brain’s ability to form new neural connections in response to illness, injury, or new environmental situations, just to name three. Nerve cells engage in a bit of conjuring known as “axonal sprouting,” which can include rerouting new connections around damaged axons. Alternatively, connections are pruned or reduced. Neuroplasticity is not an unmitigated blessing. Consider intrusive tinnitus, a loud and continuous ringing or hissing in the ears, which is thought to be the result of the rewiring of brain cells involved in the processing of sound, rather than the sole result of injury to cochlear hair cells.

The fact that the brain is malleable is not a new idea, to be sure. Psychologist Vaughn Bell, writing at Mind Hacks, has listed a number of scientific papers, from as early as 1896, which discuss the possibility of neural regeneration. But there is a problem with neuroplasticity, writes Bell, and it is that “there is no accepted scientific definition for the term, and, in its broad sense, it means nothing more than ‘something in the brain has changed.’” Bell quotes the introduction to the science text, Toward a Theory of Neuroplasticity: “While many scientists use the word neuroplasticity as an umbrella term, it means different things to different researchers in different subfields… In brief, a mutually agreed upon framework does not appear to exist.”

So the conference was dealing with two very slippery semantic concepts when it linked neuroplasticity and addiction. There were discussions of the epistemology of addiction, and at least one reference to Foucault, and plenty of arguments about dopamine, to keep things properly interdisciplinary. “Talking about ‘neuroscience,’” said Robert Malenka of Stanford University’s Institute for Neuro-Innovation and Translational Neurosciences, “is like talking about ‘art.’”

What do we really know about synaptic restructuring, or “brains in the wild,” as anthropologist Daniel Lende of the University of South Florida characterized it during his presentation? Lende, who called for using both neurobiology and ethnography in investigative research, said that more empirical work was needed if we are to better understand addiction “outside of clinical and laboratory settings.” Indeed, the prevailing conference notion was to open this discussion outwards, to include plasticity in all its ramifications—neural, medical psychological, sociological, and legal—including, as well, the ethical issues surrounding addiction.

Among the addiction treatment modalities discussed in conference presentations were optogenetics, deep brain stimulation, psychedelic drugs, moderation, and cognitive therapies modeled after systems used to treat various obsessive-compulsive disorders. Some treatment approaches, such as optogenetics and deep brain stimulation, “have the potential to challenge previous notions of permanence and changeability, with enormous implications for legal strategies, treatment, stigmatization, and addicts’ conceptions of themselves,” in the words of Clark and Nagel.

Interestingly, there was little discussion of anti-craving medications, like naltrexone for alcohol and methadone for heroin. Nor was the standard “Minnesota Model” of 12 Step treatment much in evidence during the presentations oriented toward treatment. The emphasis was on future treatments, which was understandable, given that almost no one is satisfied with treatment as it is now generally offered. (There was also a running discussion of the extent to which America’s botched health care system and associated insurance companies have screwed up the addiction treatment landscape for everybody.)

It sometimes seems as if the more we study addiction, the farther it slips from our grasp, receding as we advance. Certainly health workers of every stripe, in every field from cancer to infectious diseases to mental health disorders, have despaired about their understanding of the terrain of the disorder they were studying. But even the term addiction is now officially under fire. The DSM5 has banished the word from its pages, for starters.

Developmental psychologist Reinout Wiers of the University of Amsterdam used a common metaphor, the rider on an unruly horse, to stand in for the bewildering clash of top-down and bottom-up neural processes that underlie addictive behaviors. The impulsive horse and the reflective rider must come to terms, without entering into a mutually destructive spiral of negative behavior patterns. Not an easy task.

Who Smokes Dope, And How Much?

Marijuana stats skew perceptions of use.

Most statistical surveys of marijuana focus on a single quantitative measurement: How many people are using? But there’s a problem: More marijuana use does not necessarily translate into more marijuana users. And that’s because a clear majority of the consumption, and black market dollars, come from the heaviest smokers.

Drug policy researchers at the RAND corporation decided that frequency of use and amount of consumption were valuable parameters gone missing in most policy discussions. So they put the focus not just on use, but also on “use-days,” and pulled a number of buried tidbits from a very big data pile. If you zero in on consumption, and not just consumers, they insist, you will find a wholly different set of inferences.

For example: “Although daily/near-daily users represented less than one-quarter of past-month cannabis users in 2002 and roughly one-third of past-month users in 2011, they account for the vast majority of use-days and are thus presumably responsible for the majority of consumption,” write Rachel M. Burns and her RAND colleagues in Frontiers of Psychiatry. As with alcohol, the majority of cannabis consumption can be accounted for by a minority of users. The heaviest users, the upper 20 percent, consume 88 percent of the U.S. marijuana supply, say the RAND researchers. “Furthermore, if over time there were no change in the number of cannabis users, but the ratio of light vs. heavy users switched from 80/20 to 20/80, then consumption would increase by 250% even though there was no change whatsoever in the number of users.”

The RAND group used two data sets on cannabis consumption—the National Survey on Drug Use and Health (NSDUH) in the U.S., and the EU Drugs Markets II (EUMII) in Europe. Data included figures for past-year and past-month use, past-month use days, and past-month purchases.

Other intriguing figures come to light when you study cannabis use, as opposed to cannabis users. The researchers declared that “only 14% of past-year cannabis users [primarily males] meet the criteria for cannabis abuse or dependence, but they account for 26% of past-month days of use and 37% of past-month purchases.”

Happen to smoke blunts? That turns out to be very telling, according to the RAND study. “Perhaps the most striking contrast concerns blunts. Only 27% of past-year cannabis users report using a blunt within the last month, but those individuals account for 73% of cannabis purchases.” Casual users, it seems, don’t do blunts.

Clearly, it takes a lot of casual users to smoke as much marijuana as one heavy user. But exactly how many? The RAND researchers ran the numbers and concluded that, in terms of grams consumed per month, it would take more than 40 casual smokers to equal the intake of a single heavy user. The share of the market represented by daily/near-daily users is clearly the motive force in their analysis.

The study in Frontiers in Psychiatry also found patterns of interest on the buy side. General use took an upswing beginning in 2007. While the probability of arrest per marijuana smoking episode hovers somewhere in the neighborhood of 1 in 3,000, everything changes if you are purchasing cannabis. RAND reported that young people collectively make more purchases per day of reported use than do older users. Therefore, “statistics indicating that the burden of arrest falls disproportionately on youth relative to their share of all users may not be prima facie evidence of discrimination if making more purchases per day of use increases the risk of arrests per year of use.” Once again, those aging Baby Boomer potheads get the best deal. They have more money with which to buy bigger amounts less often, thereby greatly lessening their chances of arrest and prosecution.

This also applies to minority arrests for marijuana offenses. “Non-Hispanic blacks represent 13% of past-year cannabis users vs. 23% of drug arrests reported by those users, but they report making 24% of the buys. Thus, some of their higher arrest rate may be a consequence of purchase patterns… African-Americans may not only make more buys but also make riskier buys (e.g., more likely to buy outdoors).”

The researchers were able to draw some conclusions about the growth in marijuana usage from 2002 through 2011, based on the NSDUH data. Their main conclusion, after exploring the demographics of this 10-year record of use, is that “consumption grew primarily because of an increase in the average frequency of use, not just because of an increase in the overall number of users.”  The driver of consumption turns out to be… greater consumption. And that increased consumption is coming from… older adults. Those older adults, it turns out, are smoking more weed.

The shift is dramatic: “In 2002, there were more than three times as many youth as older adults using cannabis on a daily/near-daily basis; in 2011 there were 2.5 times more older adults than youth using on a daily/near-daily basis.” The record of alcohol and cigarette use over the same period showed no such inversion of use patterns.  And the tweeners? “In 2002, 12-17-year-olds represented 13% of daily/near-daily users; in 2011, that had dwindled to 7%.” These trends are not just the obvious result of an increase in the proportion of older adults in the population at large. Increases in the proportion of older heavy cannabis users were much greater than the general population drift.

Among the questions raised by the RAND analysis:

— Are older marijuana smokers primarily recreational, or medicinal?

—Do increased use days among older, college-educated marijuana smokers indicate greater social acceptance, or something else?

—Are younger people replacing traditional cannabis use with other substances?

—Why did Hispanic use increase more over the study period than other ethnic groups?

Burns R.M., Caulkins J.P., Everingham S.S. & Kilmer B. (2013). Statistics on Cannabis Users Skew Perceptions of Cannabis Use, Frontiers in Psychiatry, 4   DOI: 10.3389/fpsyt.2013.00138

Photo Credit: http://www.sho.com/sho/weeds/home

Holiday Decorating Abuse

America’s tragic seasonal illness.

These victims spend the holiday season awash in replacement bulbs and outdoor extension cords, the sturdy cords in orange or blue, as they monitor their surroundings with pathological hypervigilance.

A forlorn, out-of-control lightscape where a festival of moderate holiday dazzle used to reign. Oh, the humanity.

Oh, sure, the perpetrators can be cited for various misdemeanors, but rarely are the over-displays removed by the appropriate authorities. And rarely can the disordered decoraters stay sober for, say, more than a year at a time….

In the end, sometimes extreme and difficult measures are required to enable the perpetrator to stop and consider the consequences....

Happy Holidays, and here's to responsible outdoor lighting!

What Mark Kleiman Wants You To Know About Drugs

The public policy guru guiding state legalization efforts.

Mark A. R. Kleiman is the Professor of Public Policy at UCLA, editor of the Journal of Drug Policy Analysis, author of many books, and generally regarded as one of the nation’s premier voices on drug policy and criminal justice issues. Mr. Kleiman provides advice to local, state, and national governments on crime control and drug policy. When the state of Washington needed an adviser on the many policy questions they left unanswered with the passage of I-502, which legalized marijuana in that state, they turned to Kleiman.

In the past two years, Kleiman has co-authored to Q and A-style books: Drugs and Drug Policy: What Everyone Needs to Know (2011) with Jonathan P. Caulkins and Angela Hawken; and Marijuana Legalization: What Everyone Needs to Know (2012) with Hawken, Caulkins, and Beau Kilmer.

Here, excerpted from the two books, is a brief sampling of Kleiman and his colleagues on a variety of drug and alcohol issues.

Is marijuana really the nation’s leading cash crop?

“Alas, the facts say otherwise. Analyses purporting to support the claim must contort the numbers, citing the retail price of marijuana but the farmgate price of other products, or pretending that all marijuana consumed in the United States is sinsemilla, or ignoring the fact that most marijuana used in the United States is imported, or simply starting with implausible estimates of U.S. production…. marijuana [is] in the top fifteen, but not the top five, cash crops, ranking somewhere between almonds and hay, and perhaps closest to potatoes and grapes.”

How much drug-related crime, violence, and corruption would marijuana legalization eliminate?

“Not much…. Eighty-nine percent of survey respondents report obtaining marijuana most recently from a friend or relative, and more than half (58 percent) say the obtained it for free. That stands in marked contrast to low-level distribution of heroin and crack which often occurs in violent, place-based markets controlled by armed gangs.”

How much would legal marijuana cost to produce?

“The punch line is that full legalization at the national level—as opposed to only legalizing possession and retail sale—could cut production costs to just 1 percent of current wholesale prices…. This would make legal marijuana far and away the cheapest intoxicant on a per-hour basis.”

How would legalization affect me if I’m a marijuana grower?

“It would almost certainly put you out of business. At first glance, legalization might seem like a great opportunity for you…. But legalization will completely upend your industry, and the skills that made you successful at cultivating illegal crops will not have much value. A few dozen professional farmers could produce enough marijuana to meet U.S. consumption at prices small-scale producers couldn’t possibly match. Hand cultivators would be relegated to niche markets for organic or specialty strains.”

Would marijuana regulations and taxes in practice approach the public health ideal?

“If there is a licit, for-profit marijuana industry, one should expect its product design, pricing, and marketing actions to be designed to promote as much frequent use and addiction as possible. Efforts to tax and regulate in ways that promote public health would have to contend with an industry mobilizing its employees, shareholders, and consumers against any effective restriction. Since the industry profits from problem users, we should expect that lobbying effort to be devoted to blocking policies that would effectively control addiction. The alcohol and tobacco industries provide good examples.”

Can we persuade children not to use drugs?

"Even the best prevention programs have only modest effects on actual behavior, and may programs have no effect at all on drug use…. Anesthesiologists know far more about drugs and drug abuse than could possibly be taught in middle-school prevention programs; nonetheless, they have high rates of substance abuse, in part because they have such easy access.”

Why is there a shortage of drug treatment?

“Some specific categories—especially those in need of residential care, and more especially mothers with children in need of residential care—face chronic shortages. But if we had enough capacity for all those who need treatment, many of those slots would be empty because not all the people who ought to fill them want treatment.”

How much money is involved?

“Most of the numbers about drug abuse and drug trafficking that officials peddle to credulous journalists are little better than fiction. Estimates of hundreds of billions of dollars per year in international drug trade—which would make it comparable to food, oil, and arms—do not have a basis in the real world. The most recent serious estimate of the total retail illicit drug market in the United States—by all accounts the country whose residents spend the most on illicit drugs—puts the figure at about $65 billion.”

When it comes to drugs, why can’t we think calmly and play nice?

“American political analysts talk about ‘wine-track (college-educated) and ‘beer track’ (working-class) voters…. So the politics of drug policy is never very far from identity politics…. The notion that illicit drug taking is largely responsible for the plight of minorities (and of poor people generally) and that income-support programs have the perverse consequence of maintaining drug habits has been a staple of a certain form of American political rhetoric at least since Ronald Reagan.”

Are we stuck with our current alcohol problem?

"By no means…. tripling the tax would raise the price of a drink by 20 percent and reduce the volume of drinking in about the same proportion. Most of the reduced drinking would come from heavy drinkers, both because they dominate the market in volume terms and because their consumption is more price-sensitive…."

Hazelden Offers Companion to the “Big Book”

New guide attempts a modest AA update.

The founders of AA published their book, Alcoholics Anonymous (The Big Book) back in 1939. The world has changed a great deal since then, so it’s not surprising that there have been periodic calls for an update. Barring an official revision, which is unlikely, Hazelden, the Minnesota treatment organization, has published an updated companion volume to the Big Book. (Narcotics Anonymous published their version of the basic text in 1962). “The core principles and practices offered in these basic texts hold strong today,” says Hazelden, “but addiction science and societal norms have changed dramatically since these books were first published decades ago.”

Hazelden’s book, Recovery Now, billed as an easy-to-follow guide to the teachings of Alcoholics Anonymous and Narcotics Anonymous, dispenses with the divisive question of medications for withdrawal straightaway. In a foreword by Dr. Marvin D. Seppala, chief medical officer at Hazelden, the doctor makes it clear: “I agree with the majority of treatment professionals who support using these meds to help with cravings when it is appropriate to do so. Addiction is a disease that calls for the best that science has to offer.” The unnamed authors of the “little green book” agree, stating that “for some mental health disorders, medications such as antidepressants are needed. These aren’t addictive chemicals and so professionals, as well as AA and NA, accept that we can take them and still be considered clean and sober (abstinent).” There are now, as well, specific Twelve Step groups for those with both addiction disorders and mental health disorders: Dual Diagnosis Anonymous and Dual Recovery Anonymous among them.

As Seppala points out in the foreword, when some alcoholics and other drug addicts hear about the research showing that addiction is similar to many other mental and physical disorders we call diseases, it reorients their thinking amid the shame, stigma, and negative emotional states associated with active addiction. For some, it opens the door to treatment.

Okay. Hazelden, Betty Ford, and many other major treatment providers are no longer fighting a rear-guard action against a host of medications, from buprenorphine to Zoloft. But two-thirds of the Big Book consists of stories of how people recognized and dealt with their sundry addictions. That’s really about it, which tracks well with AA’s core operating principle: one drunk helping another. AA believes that much of its success stems from the fact that the program is run by the members, without direct rule setting and intervention from organizations, including their own. (All statements hold for NA as well).

What else? Recovery Now takes on another sticking point for many: the fact that “the AA Big Book and other writings include traditional male-focused and religious language, like discussing God as a ‘he.’” And there is the matter of “the realities and stereotypes of the 1930s, which is why it contains a chapter titled ‘To the Wives.’” Hazelden continues the recent tradition of broadening acceptable interpretations of “higher power.” One example given is from Samantha, a young cocaine and alcohol addict: “My higher power is the energy of this group. I call her Zelda.”

The book presents some of the psychological aspects of the AA program as a sort of reverse cognitive behavioral therapy. CBT attempts to teach people how to unkink their thinking and turn harmful thoughts into helpful ones. AA attempts to convince people to first change their behavior—“fake it until you make it”—and helpful thoughts will follow.

Perhaps the genuine sea change lies in this passage, which can be contrasted with the faith and certainty with which the Big Book proclaims that AA will work for all but the most stubbornly self-centered. Even with the myriad of choices of AA groups now available, Hazelden acknowledges that “a group based on the Twelve Steps doesn’t work for all of us. Some of us have found help in recovery groups that offer alternatives to the Twelve Steps, such as SMART Recovery, Women for Sobriety, and Secular Organizations for Sobriety.”  This is a change of heart, given that groups like SMART Recovery don’t necessarily buy the idea of total abstinence, and often structure recovery as an exercise in controlled drinking. Hazelden also suggests that many of “us” have found the necessary ongoing support for recovery at churches, mental health centers, and nonreligious peer support groups.

As for anonymity, Recovery Now states: “While Twelve Step members do not reveal anything about another member of the group, any one of us may choose to go public with our own story.” Another promising development is the proliferation of Twelve Step meetings catering to specific populations—AA meetings for African Americans, Latinos, Native Americans, women, seniors, gays, and drug-specific (Cocaine Anonymous).

In the end, one of the best arguments for attendance at the AA program (free of charge) is that many addicts have “worn out our welcome” with families and friends, “and they have a hard time putting all that behind them and supporting us completely. But at most Twelve Step recovery meetings we can find the support we need.”

Addiction in the Spotlight at Neuroscience 2013

Testing treatments for nicotine, heroin, and gambling addiction.

Several addiction studies were among the highlights at last month’s annual meeting of the Society for Neuroscience (SfN) in San Diego. Studies released at the gathering including therapies for nicotine and heroin addiction, as well as some notions about the nature of gambling addiction.

And now, as they say, for the news:

— Transcranial Magnetic Stimulation (rTMS), the controversial technique being tested for everything from depression to dementia, may help some smokers quit or cut down, according to research coming in from Ben Gurion University in Israel. Abraham Zangen and colleagues used repeated high frequency rTMS over the lateral prefrontal cortex and the insula of volunteers. Participants who got the magnetic stimulation quit smoking at six times the rate of the placebo group over a six-month period. Work in this area is limited, but there is some preliminary evidence that some addictions may respond to this form of treatment. azangen@bgu.ac.il

—Speaking of the insula—a site deep in the frontal lobes where neuroscientists believe that self-awareness, cognition, and other acts of consciousness are partially mediated—research now suggests that out-of-control gamblers may be suffering, in part, from an overactive insula. People with damage to the insular region are less prone to both the “near-miss fallacy (where a loss is perceived as “almost” a win) and the “gambler’s fallacy (where a run of luck is “due” to a gambler after a string of losses). The volunteer gamblers played digital gambling games while undergoing functional MRIs. Luke Clark of the University of Cambridge, along with researchers from the University of Iowa and the University of Southern California, uncovered a “specific disruption of both effects” in a study group with insula damage. This ties in with earlier research demonstrating that smokers with insula damage lost interest in their habit. This one remains a puzzler, and further research, that brave cliché’, is needed, especially since disordered, or “pathological” gambling is now classified in the DSM5 as an addiction, not an impulse control disorder.  lc260@cam.ac.uk

—And speaking of stimulation, if you go deep with rat brains, you can stimulate a drug reward area and reduce the motivation for heroin in addicted rats. Deep brain stimulation (DBS), an equally controversial treatment approach, now in use as a treatment for Parkinson’s and other conditions, is a surgical procedure involving the implantation of electrodes in the brain. When Carrie Wade and others at the Scripps Research Institute and Aix-Marseille University in France electrically stimulated the subthalamic nucleus and got addicted rats to take less heroin and become less motivated for the task of bar pressing to receive the drug. Earlier work had demonstrated a similar effect in rats’ motivation for cocaine use. “This research takes a non-drug therapy that is already approved for human use and demonstrates that it may be an option for treating heroin abuse,” Wade said in a prepared statement.  clwade@scripps.edu

—Too much stimulation leads to stress, as we know. And George Koob, recently named the director of the National Institute on Alcohol Abuse and Alcoholism, discussed his work on the ways in which dysregulated stress responses might act as triggers for increased drug use and addiction. Koob focused on the negative reinforcement of stressful emotional states: “The argument here is that excessive use of drugs leads to negative emotional states that drive such drug seeking by activating the brain stress systems with areas of the brain historically known to mediate emotions and includes the stress/fear-mediating amygdala and reward-mediating basal ganglia.” For Koob, “stress can cause addiction and addiction can cause stress.” gkoob@scripps.edu

—Finally, hardcore gamblers show a boost in reward-sensitive brain areas when they win a cash payout, but less activation when presented with rewards involving food or sex. The study features more volunteers playing games inside fMRI machines, and purports to demonstrated that problem gamblers are less motivated by erotic pictures than by monetary gains, “whereas healthy participants were equally fast for both rewards.” This “blunted sensitivity” in heavy gamblers suggests the possibility of a marker for problem gambling, in the form of a distorted sensitivity to reward, said Guillaume Sescousse of Radboud University in The Netherlands, during a mini-symposium at the conference. “It is as if the brain of gamblers interpreted money as a primary reward…. for its own sake, as if it were intrinsically reinforcing.” g.sescousse@fcdonders.ru.nl