Ascending and descending rates of change in blood alcohol concentrations and subjective intoxication ratings.

Subjective feelings of intoxication help determine drinking-related behavior. Most experiments in this area have examined levels of intoxication at different blood alcohol concentrations (BACs) rather than the rate of change of these variables over time. In the present experiments, the rate of change of BACs and of intoxication ratings were compared on both the ascending and the descending limbs of these variables after alcohol challenge. BACs and intoxication ratings reached peak values at the same time when alcohol consumption took 55 min. However, when consumption was rapid (10 min), intoxication ratings reached peak values earlier than did BACs. In both experiments, intoxication ratings returned to baseline sooner than did BACs. The results suggest that internal cues to the effects of alcohol decline rapidly on the descending limb of the blood alcohol curve. The present methodology provides a way to compare the rate of change of variables with different measurement scales.