by Scientists have uncovered the biological mechanisms by which alcohol dependence can make people more sensitive to pain.
The research, recently published in British Journal of Pharmacology, may lead to the development of new drugs for the treatment of chronic pain and hypersensitivity related to alcohol abuse.
“Pain is both a common symptom in patients suffering from alcohol dependence and a reason people are driven to drink again,” senior author Marisa Roberto of the Scripps Research Institute said in a statement.
Alcohol use disorder (AUD) includes conditions commonly called alcohol misuse, alcohol dependence, and alcohol addiction, affecting nearly 30 million people in the United States.
Previous research has shown that AUD can trigger the development of numerous chronic diseases such as heart disease, stroke, liver disease and some cancers.
Long-term alcohol use has also been related to pain with over half of people with AUD reporting experiencing persistent pain of some kind.
Some of the reported symptoms related to AUD include alcoholic neuropathy, a severe form of nerve damage that causes chronic pain and other symptoms.
This pain is in turn also associated with further alcohol consumption, the scientists said.
Research has also shown that AUD is linked to changes in how the brain processes pain signals, as well as changes in how the immune system is activated.
In some people who experience the withdrawal effects of alcohol, AUD can lead to a condition called allodynia in which harmless stimuli are perceived as painful.
In the new study, scientists evaluated the underlying causes of these different types of alcohol-related pain.
They compared three groups of adult mice: rodents that drank excessively, those that had limited access to alcohol and were moderate drinkers, and mice that had never been given alcohol.
The researchers found that the alcohol-dependent mice developed allodynia during withdrawal, but subsequent access to alcohol significantly reduced their pain sensitivity.
About half of the mice that weren’t dependent on alcohol also showed signs of increased pain sensitivity during alcohol withdrawal.
However, unlike addicted mice, this was not undone by re-exposure to alcohol.
The researchers then measured the levels of inflammation-related proteins in the animals.
They found that while these molecules were elevated in both addicted and non-addicted animals, specific ones were increased only in addicted mice.
Based on this observation, they suggested that different biological mechanisms may drive the two types of pain.
“These two types of pain vary greatly, which is why it’s important to be able to distinguish them and develop different ways to treat each type,” said study co-author Vittoria Borgonetti.
The new findings also point to the types of proteins that may be useful as drug targets to combat alcohol-related pain.
Scientists are continuing to see how these molecules could be used to diagnose or treat alcohol-related chronic pain conditions.
“Our goal is to unveil new potential molecular targets that can be used to distinguish these types of pain and potentially be used in the future for the development of therapies,” said Nicoletta Galeotti, another study author.
