The Latest Science on Addiction and Treatment
Ever wonder why alcoholism seems to run in families? A sibling-brain study just discovered why.
- Sibling Brains Suggest Addiction Is Hereditary. [Science]
Dominating the week's addiction science news was a brain study of 47 sibling pairs—one a hard-core chronic addict, the other free of the disease. MRI scans revealed identical irregularities in key addiction-related regions of the brains—both between sibs and across the entire group—offering the first-ever concrete confirmation of the long-suspected link between addiction and heredity. The high-tech photos also show that these brain bloopers weren't the result of addictive behavior but, more likely, a cause of the condition.
Conducted at Cambridge University, the study was published in the journal Science, which considered it sufficiently path-breaking to warrant a commentary by Dr. Nora Volkow, the world-class neuroscientist who heads the National Institute on Drug Abuse (NIDA) under President Obama. Yet as breathlessly as the story was covered, few reporters bothered to read the Volkow brief, which points out that the differences between the sibling brains were at least as provocative as the likenesses. (Hat tip to Fix columnist Maia Szalavitz, who lucidly decodes the study on Time’s Heartland blog.)
For pointy-headed readers, the two main findings regarding identical irregularities were (1) a weaker frontostriatal circuit, which connects the prefrontal cortex—the self-control command center—to other white matter responsible for impulse control, and (2) a bigger putamen, a motor skills–and–learning regulator already implicated in the development of addiction. As for where the addicts differed from their sib? (1) a weaker medial orbitofrontal cortex (OFC), which plays a role in addiction to the extent that it directs the planning of behavior in terms of sensitivity to reward and punishment, and (2) a smaller precuneus, the seat of self-consciousness that, when disrupted, can lower tolerance for craving and frustration.
The BBC went so far as to track down one of the sibling pairs for an interview: two middle-aged women, longtime crack addict Sophia, with her "pallor," "nervousness" and stringy hair, and the "smartly dressed" Theresa, who sports an attention-getting Cleopatra hairdo and describes herself as a "control freak." We were hard-pressed to tell which was which.
- Will Anti-Smoking Drug Help Cokeheads Kick Their Habit? [Drug and Alcohol Dependence]
No pharmacological treatment exists for addiction to cocaine, methamphetamine or other stimulants. While the big money and glory lie in research into vaccines—which will take another decade (if ever) to get to market—more clinically oriented researchers are looking closer to home. How cool would it be if a drug already on pharmacy shelves could break an addict's cocaine stranglehold?
For example, scientists at the University of Pennsylvania's Treatment Research Center speculate that Chantix (varenicline), the only drug specifically made and marketed for nicotine addiction, might work against blow because of its unique action. Chantix is a partial nicotinic receptor agonist—it sparks the same neuronal targets that are stimulated by nicotine. But where cigarettes have a gigawatt effect, Chantix produces only a faint flicker, causing an uptick in the feel-good brain chemical dopamine that counters cravings. Plus, it blocks nicotine from the receptor because it is already occupying it. Testing their hypothesis in a study of 37 cocaine addicts, they found that varenicline had a small but significant efficacy. The Chantix-takers experienced markedly lower levels of the so-called reward effect compared with their placebo counterparts. Still, the drug only slightly reduced the actual number of abstinent days (its primary endpoint). That's not a deal-breaker, however, as Chantix has only modest success at its anti-smoking application, besting the cold-turkey technique by anywhere from 15% to 23%. But a drug with even a modest effect against coke cravings would be better than nothing.
- FDA Trounces Painkiller-Producing Plant [Fierce Pharma]
Pharma manufacturing plant shutdowns rarely make big news unless they cause major drug shortages, such as the ongoing Adderall drought. Yet in recent years, the drug industry has shown signs of losing its grip on quality control, especially in the production of over-the-counter (OTC) products. Last December, Swiss drug giant Novartis shuttered its huge painkiller factory in Lincoln, Nebraska, amid a full-on investigation by the Food and Drug Administration (FDA). The company had to recall its entire Excedrin line. The plant also made heavy-duty prescription painkillers such as oxycodone ER, percocet, morphine sulfate and Endocet—these, too, were contaminated.