Sensitivity to alcohol’s rewarding effects increases with age: New study

May 21, 2024

According to the results of a new study published in the journal Alcohol: Clinical & Experimental Research, adult brains are more sensitive to the reinforcing ‘reward’ effects of alcohol compared to adolescent brains. The study, carried out by a team of researchers from Bucknell University in Pennsylvania, U.S., is the first research to evaluate brain activity associated with pleasurable effects from a single exposure to alcohol, and demonstrates that one single exposure to a moderate dose of alcohol initiates brain activity that stimulates drug-seeking behaviour in potentially higher-risk groups.

“Everyone doesn’t feel the same reward from their initial encounter with alcohol,” says Dr. Judy Grisel, the study’s senior author, in a press release. “In certain individuals, like myself, they experience the kind of positive response where they want to feel that way again and are drawn to more. And the reaction to that drug — in this case, alcohol — could put them at higher risk of disordered use.”

The study was carried out in mice and found that adult mice were more sensitive to the effects of alcohol than adolescent mice, while the outcomes also depended on sex and endorphin levels. Among females, adolescents were stimulated by alcohol consumption, but insensitive to its locomotor effects as adults, while among males, adolescents were insensitive to its effects, and adults were sedated following alcohol consumption.

“Reduced sensitivity to alcohol’s reward may reflect increased risk for alcohol use disorders, as organisms tend to increase self-medication in the absence of reward,” Dr. Grisel added. “Reduced sensitivity to sedation and reward in adolescents may increase susceptibility for addiction, in line with current understanding that young people have exaggerated risk for developing drug use disorders.”