Heavy drinkers reported more positive and rewarding effects, while light drinkers reported stronger sedation and sluggishness.
New research suggests that a person’s response to alcohol can predict their future drinking behaviour, including their frequency of binge drinking and the risk of developing an alcohol-use disorder. Andrea C. King, Ph.D., professor of psychiatry and behavioural neuroscience at the University of Chicago and colleagues found that heavy drinkers actually experience greater sensitivity to the rewarding and stimulating effects of alcohol, along with lower sedation. This “double whammy” of alcohol effects predicted those who progressed to more severe drinking and alcohol-use disorders over two years of follow-up, researchers discovered.
Researchers recruited nearly 200 subjects between the ages of 21 and 35 and without alcohol dependence, divided into heavy drinker and light drinker groups. Heavy drinkers reported consuming 10-40 drinks on average per week, with at least one weekly binge episode. Light drinkers drank between 1 and 5 drinks on average per week and rarely binged.
The subjects were brought to a living room-like setting in the laboratory on three separate occasions and given one of three drinks: a placebo, a low dose of alcohol, or a high dose of alcohol, each disguised with flavored drink mix. After finishing the drink, subjects filled out survey questions about how they were feeling and took regular breathalyser tests for three hours.
While the light drinkers were more sensitive to the overall effect of the alcoholic drinks than heavy drinkers, how they described the experience was very different. Heavy drinkers reported more positive and rewarding effects, while light drinkers reported stronger sedation and sluggishness.
The researchers then followed their subjects for two years, asking them four times a year to report on past-month drinking behaviour, including the number of times they had engaged in binge drinking behaviour.
Over the 2 years, the heavy drinkers fell into four groups: those that reduced binge drinking (“gradual maturing”), those that maintained a moderate or high frequency of binge drinking, and those who increased binge drinking episodes (“exacerbating”). Subjects in the “exacerbating” group also drank more frequently and in higher quantities, suffered more alcohol-related consequences, and were more likely to qualify for a DSM-IV diagnosis of alcohol abuse or dependence.
The researchers suggest that an individual’s initial response could predict later drinking behaviour. Subjects who exacerbated their binge drinking habits were more likely to have reported positive and stimulating effects of alcohol in the laboratory, even though they were unaware at the time of what they were drinking.
The researchers propose a revised theory of alcohol response that may impact how clinicians may spot and pre-empt unhealthy drinking habits.
“If we know more about who’s going to become a problem drinker, we may be able to prevent future escalations and intervene earlier, before development of severe alcoholism,” King said. “The stimulant-type responder could learn that while such a response pattern may not be their fault, it could put them at risk for longer-term problems and consequences.”
Source: Rewarding, Stimulant, and Sedative Alcohol Responses and Relationship to Future Binge Drinking. A. C. King, H. de Wit, P. J. McNamara, D. Cao. Archives of General Psychiatry, 2011; 68 (4): 389 DOI