Scientists May Have Discovered The Brain Pathways That Cause Alcoholism
Alcoholism is a devastating disease that doesn’t just affect the problem drinker. It has a ripple effect that tears apart families and devastates communities.
According to The Washington Post, the rate of alcoholism among U.S. adults has risen 49% since the beginning of the Millennium. Approximately one in eight American adults, or 12.7% of the U.S. population, now meets diagnostic criteria for alcohol use disorder.
Alcoholism can lead to serious health problems, including fetal alcohol spectrum disorders, hypertension, cardiovascular diseases, stroke, liver cirrhosis, several types of cancer and infections, pancreatitis, and type 2 diabetes.
Problem drinkers are also at risk for serious injuries due to impaired coordination and a predilection towards violent behavior.
Alcoholism is one of the most serious health issues affecting the U.S., but we know very little about its causes. Why can some people drink occasionally while others become compulsive? Why do compulsive drinkers continue to drink even when faced with serious consequences?
One of the leading theories is that alcoholism is genetic. According to How Stuff Works, “children of alcoholics are four times more likely to become alcoholics themselves.”
Alcohol dependence is not only psychological but can be physiological as well.
Prolonged exposure to alcohol makes some people reliant on the drug to experience pleasure and alleviate pain. The intense withdrawal symptoms felt by regular users can also push them to grab the bottle.
New research by the Salk Institute may completely change how we think about alcoholism and alcoholics, though. Salk’s scientists believe they have found a brain circuit in mice that controls compulsive alcohol drinking.
“I hope this will be a landmark study, as we’ve found (for the first time) a brain circuit that can accurately predict which mice will develop compulsive alcohol drinking weeks before the behavior starts,” says Kay Tye, a professor in the Systems Neurobiology Laboratory.
“This research bridges the gap between circuit analysis and
alcohol/addiction research, and provides a first glimpse at how representations
of compulsive alcohol drinking develop across time in the brain,” Tye
It all began with an experiment on how binge drinking affects the brains of mice.
The researchers provided the animals with alcohol to examine their consumption. Then, they added a bitter taste to the drink to see which animals continued to consume even after experiencing negative consequences.
In the process the researchers identified three types of drinkers: low drinkers, high drinkers, and compulsive drinkers. The compulsive drinkers showed insensitivity to negative consequences.
“In the process, we stumbled across a surprising finding where we were actually able to predict which animals would become compulsive based on neural activity during the very first time they drank,” Cody Siciliano, first author and assistant professor in the Department of Pharmacology at Vanderbilt University, said according to Salk.
Some of the mice were found to be susceptible to binge-drinking even before they had a sip of alcohol.
The researchers then studied neural activity in two parts of
the animals’ brains associated with responding to adverse events and behavioral
They found that the development of compulsive alcohol
drinking was related to neural communication patterns between the two brain regions
and was a biomarker for predicting future compulsive drinking.
They, then used optogenetics to control activity in the neural pathways in the mice and were able to either increase the compulsive drinking or reduce it. “Now, we can look into the brain and find activity patterns that predict if mice will become compulsive drinkers in the future before the compulsion develops,” says Tye.
“We do not know if this brain circuit is specific to alcohol or if the same circuit is involved in multiple different compulsive behaviors such as those related to other substances of abuse or natural rewards, so that is something we need to investigate,” Tye continued.
If humans have similar neural pathways as the mice in the study, it could have a profound effect on how alcoholism and, possibly other addictions, are treated. The solution could be as simple as controlling the neural pathways that lead people to compulsive behaviors.
It could also allow people to learn whether they are prone to alcoholism or not, preventing many from developing the disease in the first place.