The development of alcohol tolerance: acute recovery as a predictor.

Two experiments examined individual differences in the rate of alcohol tolerance development as a function of acute recovery. Male social drinkers (n = 18) were trained on a complex psychomotor task and subsequently returned for four drinking sessions in which they received the same dose (0.84 ml absolute alcohol/kg) and performed the task at intervals while blood alcohol concentrations (BAC) rose and fell (peak BAC = 77.2 mg/dl). A subject's acute recovery from the impairing effect of alcohol during session 1 was measured by the difference in his performance at the same BAC on the rising and the falling limb of the curve. Rate-of-tolerance development was measured by the rate of change in the subject's average impairment under the alcohol during sessions 1-4. Acute recovery scores in both experiments significantly predicted the rate at which tolerance developed, accounting for 64% of the variance in these scores (P less than 0.0001). Subjects who displayed more acute recovery developed tolerance more quickly. The evidence was considered to imply that the same process may give rise to both acute recovery and tolerance.