Acute rewarding and disinhibiting effects of alcohol as indicators of drinking habits.

Rationale: Laboratory studies have reliably shown that heightened sensitivity to the rewarding effects of alcohol is associated with heavier drinking patterns. More recently, there has been research to suggest that heightened sensitivity to the disinhibiting effects of alcohol might also contribute to drinking habits. Most research on the acute effects of alcohol has focused on drinking magnitudes averaged across participants with little attention paid to how individual differences influence alcohol abuse potential. In large part, this is due to limited sample sizes in previous laboratory studies.

Objectives: This study overcomes previous limitations by testing the degree to which individual differences in acute sensitivity and tolerance to the rewarding and disinhibiting effects of alcohol relate to drinking behavior in a large sample size.

Methods: Data from six laboratory studies were aggregated to comprise a sample of 181 adults. Participants' level of "liking" (the effects of alcohol) and disinhibition were assessed following 0.65 g/kg alcohol once during the ascending limb of the blood alcohol concentration (BAC) curve and again at the same BAC during the descending limb of the curve. The measures were also assessed following placebo.

Results: Alcohol increased ratings of liking and behavioral disinhibition. Heavier drinking was associated with heightened sensitivity to liking on the ascending limb. Additionally, those who showed reduced acute tolerance to both disinhibition and liking were also heavier drinkers.

Conclusions: These data suggest that individual variability in liking the effects of alcohol and persistent disinhibition are key indicators of drinking habits.