Alcohol Releases “Feel-Good” Chemicals in Your Brain
Author Jennifer Mitchell and her colleagues recruited 13 heavy drinkers and 12 people who do not drink heavily to use as a control group. Each participant received an injection of a radioactive drug that would light during PET scans of their brains. This drug binds to opiate receptors, so in this way researchers could locate receptors in the participants' scans.
After locating the receptors, the research team had participants drink alcohol, and then re-injected them with the radioactive drug. The team expected to see fewer "lights" because the alcohol would release natural endorphins that bind to the receptors before the tagged drug could get to them. That is exactly what happened.
"This is something that we have speculated about for 30 years based on animal studies, but have not observed in any human beings until now," said Dr. Mitchell. "It provides the first direct evidence of how alcohol makes people feel good."
Whenever there was more activity in the orbitofrontal cortex of their brains, the heavy drinkers reported more feelings of intoxication that this was not true of the control group.
"This indicates that the brains of heavy, problem drinkers are changed in a way that makes them more likely to find alcohol pleasant, and it may be a clue to how problem drinking develops in the first place," said Dr. Mitchell. "That greater feeling of reward might cause them to drink too much."
The results of this study may help researchers design drugs that target the opiate receptors that are involved when a person drinks alcohol.
This study was published in the journal Science, Translational Medicine.