A prospective evaluation of how a low level of response to alcohol predicts later heavy drinking and alcohol problems.

BACKGROUND AND OBJECTIVES: Evaluations of how a genetically influenced characteristic, such as the low level of response (a low LR) to alcohol, relates to later heavy drinking and alcohol problems usually include environmental contributors. The best way to understand how LR works in the context of these additional characteristics is to study the process prospectively, but such analyses tend to be complex and the papers are sometimes cluttered with jargon. This report attempts to offer a more straightforward description of the results from such a prospective model of how a lower LR at age 20 relates to alcohol outcomes at age 40. METHODS: A structural equation model of LR at age ∼20, outcomes of heavy drinking and problems at age ∼40, and additional characteristics at age ∼35 were tested in 378 men from the San Diego Prospective Study. RESULTS: The results support both direct effects of age-20 LR on age-40 heavy drinking and alcohol problems, as well as indirect effects of LR through characteristics of these men at age 35. The latter include using alcohol to cope with stress and heavier drinking among peers. CONCLUSIONS: A low LR to alcohol is an example of how both genes and environment can contribute to the risk for adverse alcohol outcomes. The identification of mechanisms through which LR impacts on later heavy drinking and problems can be approached in cross-sectional studies, but those may not be as sensitive as longitudinal models for identifying additional potential mediators of the LR-to-outcome relationship.

The overlap in predicting alcohol outcome for two measures of the level of response to alcohol.

BACKGROUND: Two different measures have been used to establish a person's level of response (LR) to alcohol as a risk factor for alcohol use disorders. LR values established by the alcohol challenge protocol and the Self-Report of the Effects of Ethanol (SRE) questionnaire usually correlate at 0.3 to 0.4, up to 0.6. However, it is not clear how this correlation relates to the ability of each measure to predict alcohol outcomes. This paper evaluates that overlap. METHODS: Sixty-six Caucasian males (mean age = 22 years) from 2 protocols participated in alcohol challenges with 0.75 ml/kg of ethanol, filled out the SRE, and were followed with a structured interview approximately 5 years later. The relationship between the subjective feelings of intoxication at the time of peak breath alcohol levels from the alcohol challenge and the SRE score for a time early in the drinking career were evaluated regarding predicting the drinks per occasion in the 6 months prior to follow-up. RESULTS: Cross-sectional correlations between alcohol challenge and SRE LR's ranged from -0.25 (p < 0.05) to -0.32 (p = 0.02) for the full sample, and the 2 LR measures correlated with drinking at follow-up (-0.26 and 0.41, respectively). The SRE measure was more robust than the challenge in a regression analysis predicting the outcome in the context of other baseline predictors (e.g., drinking at baseline). As much as 60% of the ability of the more well established (gold standard) alcohol challenge LR to predict outcome was shared with the SRE. The alcohol challenge accounted for as much as 44% of the ability of the SRE to predict outcome. CONCLUSIONS: The SRE-generated LR overlapped considerably with the alcohol challenge LR in the ability to predict future heavier drinking.

Clinical implications of tolerance to alcohol in nondependent young drinkers.

BACKGROUND: Ten percent of teenagers and young adults with no alcohol diagnosis and a third of those with alcohol abuse report tolerance to alcohol. However, relatively few data are available on the clinical implications of tolerance in nondependent men and women. METHODS: Data were gathered from 649 18-to-22-year-old drinking offspring from the Collaborative Study on the Genetics of Alcoholism (COGA) families. The prevalence and clinical correlates of tolerance were evaluated across subjects with no DSM-IV alcohol abuse and no tolerance, similar individuals with tolerance, subjects with alcohol abuse but no tolerance, and individuals with both alcohol abuse and tolerance. RESULTS: Tolerance was associated with an almost doubling of the number of drinks needed to feel alcohol's effects, and correlated with additional alcohol-related problems. In regression analyses, the most consistent and robust correlates of tolerance were the maximum number of drinks and alcohol problems, and tolerance remained informative after covarying for drinking quantity. CONCLUSIONS: Tolerance to alcohol may be a useful concept regarding nondependent drinkers that is not just a proxy for alcohol quantity but also reflects the presence of additional problems.