New Study Reveals Why Many People Can't Stop Drinking
How to know if your brain's "brake" is functioning properly
According to the National Abuse on Alcohol Abuse and Alcoholism, 26.9 percent of American adults reported that they engaged in binge drinking in 2015, and 15.1 million adults had Alcohol Use Disorder (AUD), which is defined as "a chronic relapsing brain disease characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences." According a more recent study, one out of every eight Americans struggles with alcohol abuse, which is especially on the rise for women, minorities, and senior citizens.
But, in spite of the fact that it's officially characterized as a "brain disease," we still treat AUD as a self-control issue. "Why can't you just stop?" friends and family members will often say to someone struggling with alcohol abuse—a phrase that, while well-intentioned, often has the counterproductive effect of plunging the victim into a greater state of guilt, shame, and self-abuse. Now, a new study published in the Journal of Neuroscience further indicates that the reason some people seem incapable of putting down the bottle even after they've started stumbling around or slurring their words may be due to a malfunction in the brain.
University of California Santa Barbara neuroscientist Karen Szumlinski and her colleagues uncovered a mechanism in a small brain structure called the bed nucleus of the stria terminalis (BNST), which helps people assess how alcohol is affecting their body and modifies their urge to drink any more.
"If a little bit of intoxication is making you nervous, the BNST is doing its job," Szumlinkski said.
The researchers discovered that the BNST is unique in that it includes a "brake" mechanism that helps limit alcohol consumption by releasing a scaffolding protein called Homer2. However, if the BNST fails to function properly, you lose the ability to realize you've had enough to drink, and continue consuming more alcohol.
The researchers tested this by manipulating the protein in mice, and found that when they reduced the expression of Homer2 in the BNST, the mice binge drank more—a lot more.
"It really showed that something's going on when you drink alcohol," Szumlinski said. "[BNST] serves as a brake to reduce or at least curb your alcohol consumption. But if any kink happens in that little bit of signaling there, you lose the brakes. Your brake line has been cut, and now you exhibit uncontrolled drinking behavior."
Skeptics might say, "Well, so what? It's mice." But the reason mice are often used in lab testing is because they share a lot of the same genetic and neurological characteristics as humans, including but not limited to the complex brain processes that drive people to binge drink.
"How we perceive how drunk we are is going to influence our subsequent drinking," Szumlinski said. "Although their behavior is telling us they are completely intoxicated, maybe they don't feel hammered. Or maybe when they're feeling drunk, they don't perceive that as a bad thing. Their awareness of their intoxicated state does not line up with their high-dose alcohol preference or their drinking behavior. And so presumably that might have something to do with BNST glutamate function."
The study also disputes the widespread belief that how much you drink depends on how high your tolerance levels are.
"There's a lot of literature, including lots of human data, that says if you are more sensitive to the intoxicating effects of alcohol, you are less likely to drink," Szumlinski said. "This study says you can be incredibly sensitive to the intoxicating effects of alcohol, but that doesn't necessarily feed back on you the way it should."
Further research needs to be done to confirm that this brake mechanism functions the same way in humans and, if so, how to help treat people whose BNTS might not be working properly. But, for now, the takeaway is that we should recognize that—for some people—switching to water isn't as easy as it seems. And for more on the ways alcohol affects your body, see Why Alcohol Wakes You Up in the Middle of the Night.