ALDH2 status, alcohol expectancies, and alcohol response: Preliminary evidence for a mediation model

Background: A genetic variant in the alcohol-metabolizing enzyme (aldehyde dehydrogenase; ALDH2*2 allele), common in individuals of Asian heritage, has been associated with both physiologic response to alcohol and alcohol consumption. Prior research has also demonstrated that those with ALDH2*2 alleles have lower positive alcohol expectancies than those without these alleles. This preliminary study was designed to test whether the level of response to alcohol is the mechanism by which ALDH2 status may affect alcohol expectancies. Methods: Data were collected from 32 Asian American college students (14 women and 18 men). By use of a randomized, double-blind design, participants were administered oral placebo and alcohol at separate laboratory sessions. Data included blood tests to establish ALDH2 status, questionnaire measures of demographic information and alcohol expectancy, and several physiologic measures collected after placebo and alcohol administration. Results: ALDH2 status was related to alcohol response measures for both men and women. ALDH2 status was also related to tension reduction expectancies for women and to expectancies for cognitive behavioral impairment for men. In the male sample, the ALDH2/expectancy relationship was fully explained by the level of response to alcohol. Conclusions: These results represent a first step in understanding the mechanisms by which genetic factors, such as ALDH2 status, can affect alcohol-related learning.