The Latest Research on Drugs and Addiction
Cocaine really depresses lab mice, Low-Income smokers have the most trouble quitting, and scientists identify biological markers that predict alcohol withdrawal seizures.
- The Mouse in the Addiction and Depression Maze [Scientific American]
Unlucky is (s)he who has both addiction and depression. But determining which came first can be daunting. Researchers at New York’s Mount Sinai School of Medicine wanted to explore this chicken-and-egg question behind mood disorders and drugs: Does substance use cause changes in the brain that produce depression, or is depression a byproduct of using? Out came the lab mice. In experiments published in January's issue of Neuron, the critters that were first given coke for a week and then exposed to stress got a case of the blues lasting much longer than in their coke-free peers. After cutting open their brains (talk about stress!), the neuroscientists found coke-users had lower levels of reward-center molecule histone deacetylase (HDAC)—exactly like mice that are bred to be prone to stress and depression. When researchers artificially stimulated HDAC, the result was a brighter mood. When it was dialed down, darkness set in.
The take-home? Don’t do coke for a week straight. Also, cocaine and other substances may spark a neurochemical reaction that turns down the expression of HDAC, so if you weren’t depressed before you started using, you probably will be soon, creating a mutually reinforcing addiction-depression loop.
- The Neuroscience of Chasing the Dragon [Science Daily]
HDACs are one of the hottest spots in addiction neuroscience because they appear to directly manipulate the expression of certain genes in one of the brain's reward regions, like a finger on a volume fader. In another HDAC study reported in Neuron, researchers at the University of Southwestern Texas made a discovery that could answer a common junkie's question: Why do we consume more and more alcohol or drugs in a futile pursuit of ever-diminishing satisfaction? Studying the same HDAC molecules in the same reward region of the brains as the coke-taking mice, these researchers found that the drug set in motion HDAC activity that limited not only the pleasure payoff but also the long-term memory of the experience.
The take-home? A built-in mechanism making you eternally frustrated and stupid—unable to remember, and therefore learn not to do the same thing over again and expect a different result—appears to define addictive behavior.
- The Poorest Smokers Make the Poorest Quitters [The American Journal of Public Health]
A new study of nicotine addicts in Arkansas—the third poorest state per capita—found that those with the least income had the lowest success rate in a statewide smoking-cessation program headed by Dr. Christine Sheffer, a former University of Arkansas prof. Although those at the top of the financial ladder and those at the bottom had equal quit rates right after the cognitive behavioral nicotine patch treatment, the poorest quitters were, three months into recovery, 55% more likely to start smoking again—and at six months, 250% more likely. In the March issue of the American Journal of Public Health, Sheffer offers several explanations: (1) Stressful money worries, job woes and discrimination plague the poor, while nicotine floods the brain with feel-good dopamine, making cigarettes a relatively cheap sedative. (2) Rates of teen smoking increase as household income decreases, and the earlier you start the harder it is to quit. (3) Lower-paying jobs are less likely to be protected by no-smoking rules.
The take-home? "The evidence-based treatments that are around have been developed for middle-class patients," says Sheffer. "So in therapy we talk about middle-class problems."
- Bonus Detox-Safety Brief [European Addiction Research]
For detoxing drinkers, withdrawal seizures pose a major health risk. German researchers have now identified biological markers to better predict the probability of seizures. They advise rehabs to measure both homocysteine (HCT) and carbohydrate-deficient transferrin (CDT) before detox in all alkies with a vulnerable profile.