Individual differences in alcohol responsivity: physiological, psychomotor and subjective response domains.

OBJECTIVE: Psychometrically stable measures of individual differences in response to consuming alcohol were developed as part of an ongoing project investigating "high-tolerant" drinking drivers. The derived measures were correlated with diagnostic criteria of alcohol abuse and dependence, as well as drinking frequency, heavy drinking and tolerance estimations.
METHOD: Male subjects (N = 94), 21 to 59 years old, participated in each of two identical alcohol consumption sessions (mean dose = 0.78 g/kg). Multiple response measures obtained before and after drinking (mean BAC = 78 mg/dl, descending) were used to compute postconsumption regression residuals that were factor analyzed.
RESULTS: Factors reflecting psychomotor, subjective and physiological responsivity to alcohol were extracted. Confirmatory factor analyses indicated consistent psychomotor and physiological factor structures across the two testing sessions, but a bifurcation of the subjective measures. Test-retest correlations of the responsivity residuals indicated medium to moderately large effect sizes (mean = .32, range = .15-.51). Residuals summated within each response domain indicate moderate internal consistency (mean = .56, range = .45-.72) and higher reliabilities than single measure indices (range = .53-.59). Summated residuals within the response domains suggest diminished responsivity is associated with more severe alcohol-use diagnoses and were differentially predictive of self-reported drinking practices.
CONCLUSIONS: Alcohol responsivity is multidimensional. Individual differences across different domains can be measured reliably and are associated with different patterns of alcohol use and abuse. Greater attention should be given to the specific domain of alcohol responsivity measures obtained in past and future research that relates individual differences to alcohol-related problems.