Drinking in a social setting triggers the release of dopamine, which causes a euphoria not seen when drinking alone, according to a new study. Researchers hope that by identifying which part of the brain is stimulated by social drinking, it will lead to a better understanding of problem drinking.
While drinking with friends or coworkers is often associated with good feelings and a cheerful mood, drinking alone conjures up visions of loneliness, depression, and sometimes alcoholism. Alcohol consumption is known to release dopamine in the brain, leading to a feeling of euphoria. Indeed, chasing the dopamine high associated with alcohol can lead to problem drinking.
In a new study, researchers from the University of Texas El Paso (UTEP) examined the biological process behind social drinking, the role of dopamine and how it produces these positive feelings.
“Social environments influence how individuals respond to alcohol, but there are no mechanistic studies on how and why this occurs,” said Dr. Kyung-An Han, a biologist at UTEP and co-author of the study.
To study the effect of alcohol consumption on behavior in a social setting, researchers used intoxicated fruit flies or Fruit flyIt may seem like an odd choice, but it really isn't: we share about 75% of the genes that cause human diseases.
Flies were exposed to ethanol vapor either alone or in a group setting, and their average speed was measured to determine the degree of ethanol-induced response. The researchers observed that 'solo-drinking' lone flies showed a slight increase in movement, while those intoxicated in a group exhibited significantly increased speed and movement.
UTEP Study Shows How Social Drinking Increases Euphoria
They then tested the dopamine levels of the drunk flies and compared them to a control group. Despite having normal or increased dopamine levels, the drunk flies produced only a small increase in activity when they were alone. But this was not the case when they were in a group, as the drunk flies with increased dopamine levels showed even greater hyperactivity.
“We showed that both social environments and dopamine act together to increase flies' response to ethanol,” Han said.
Finally, the researchers set out to determine which of the five dopamine receptors in the brain contributed most to this process. They found that it was the D1 dopamine receptors, which are known to play important roles in things like learning, memory, and reward mechanisms.
“The human D1 receptor gene is linked to Alcohol Use Disorder, and this study provides experimental validation for this,” Han explained. “For the team, the identification of the D1 receptor is crucial as it provides researchers at UTEP and beyond with a blueprint for follow-up studies.”
According to 2019 statistics from the World Health Organization (WHO), an estimated 400 million people aged 15 and over (7% of the world's population) worldwide are living with an alcohol use disorder (AUD). Alcohol abuse and alcohol dependence were separate diagnoses under the previous edition of the psychiatrists' diagnostic 'bible', the DSM-IV. However, with the publication of the current DSM-5, the two conditions have been combined into a single disorder, AUD.
The researchers hope their findings will shed light on future AUD treatments.
“Our study provides scientific information supporting the idea that the brain interprets and processes a person's social environment and that this signal converges on the dopamine system, which is also activated by alcohol consumption,” said Dr. Paul Rafael Sabandal, assistant professor of biological sciences and the study's other corresponding author. “It gives us as researchers an idea of which brain region and components may serve as the meeting point for all the signals that contribute to AUD.”
“The opportunity to work on projects that have a positive impact that can be implemented at scale was one of the reasons I became a scientist,” Han added. “I am humbled to know that our work has the potential to help people live better lives, and our team will continue to strive to achieve this goal.”
The study was published in the journal Biology of Addiction.
Source: UTEP