A low subjective response (SR) to alcohol is associated with fewer acute negative consequences in a heavy drinking sample, researchers say.
Study authors speculate that a low SR may protect against problems in the short term, but likely becomes a risk factor for longer-term problems as tolerance to alcohol develops.
Prior studies have shown that a low subjective response (SR) to alcohol is a risk factor for alcohol use disorders (AUDs). Research on moderate drinkers has shown that acquired tolerance is different from initial response, and is also significantly associated with drinking problems.
A new study of linkages among early SR, acquired tolerance, alcohol use, and alcohol-related problems among problem drinkers has found that a low, early subjective response - an ability to "hold one's liquor" - may protect against problems in the short term, but likely becomes a risk factor for longer-term problems as tolerance to alcohol develops.
"People who feel less impaired after drinking are at increased risk for developing AUDs," William R. Corbin, corresponding author of the study from Arizona State University, said.
"A low SR to alcohol may result from differences in drinking history. For example, with heavier drinking, tolerance develops whereby individuals feel less intoxicated than they used to at the same level of consumption.
"Tolerance is a well-established correlate of alcohol problems and is one of the diagnostic criteria for alcohol dependence. Because studies of SR must be conducted with individuals of legal drinking age, 21 years or older, participants typically already have considerable drinking experience, making it difficult to determine if differences in SR are due to innate individual differences or differences in the acquisition of tolerance.
"Our study is only the second to try to differentiate between innate differences in SR and tolerance, and understand their unique relations with drinking behaviour and alcohol problems.
"The prior study sample was comprised of relatively light drinkers, while the current study examined the unique role of initial SR and tolerance in a sample of heavy drinking young adults," Corbin said.
Corbin and his colleagues examined associations between early subjective response and acquired tolerance and both drinking behaviour and alcohol-related problems, within a sample of 113 heavy drinking young adults (75 men, 38 women) who had volunteered for a clinical trial of naltrexone in combination with brief motivational counselling.
"Consistent with the one prior study on this topic, we found that both initial SR and tolerance were related to drinking behaviour, with heavier drinking among those with a low initial SR and greater acquired tolerance," Corbin said.
"In direct contrast with the prior study, a low initial SR was associated with fewer alcohol-related problems in this heavy-drinking sample, and tolerance was not a significant predictor of problems.
"The participants in our sample were young heavy drinkers who had not yet passed through the peak period of risk for AUDs.
"We speculate that protection against alcohol-related problems among young heavy drinkers with a low SR may allow them to continue to drink more heavily as they miss the 'stop' signal to cease drinking. A continued escalation in heavy drinking may ultimately contribute to an increased risk for AUDs," he said.
Corbin said this study provides further evidence for differential roles of initial SR and acquired tolerance.
"Whereas both were associated with drinking behaviour, only initial SR was related to AUDs among heavy drinkers with considerable acquired tolerance," he said.
"This finding highlights the importance of assessing both initial SR and tolerance and suggests that the relation between initial SR and alcohol problems may change over the course of an individual's drinking history.
"A low initial SR may contribute to heavier drinking and more related problems early in an individual's drinking history and prior to the development of substantial tolerance. However, our findings suggest that, as tolerance develops, the combination of an initially low SR and tolerance may protect against acute alcohol problems," he added.
The study has been published in Alcoholism: Clinical and Experimental Research. (ANI)