The Effect of Stress and Genetic Factors on Alcohol Consumption Among Males in Olancho District, Honduras
Alcoholism is a major public health problem globally. More than twenty studies have examined the association between the neurotransmitter dopamine DRD2 TaqI polymorphism and the onset of alcoholism, with half supporting an association. This study was based on the assumption that there is a relationship between the presence of the DRD2, one’s exposure to stress, and alcohol consumption. We examined the gene-stress interactional model in a sample of 309 males of Mayan descendents in the Olancho district of Honduras (age range 18-87). Participants were interviewed by a health care professional and blood samples were obtained for genetic identification. The Michigan Alcoholism Screening Test (MAST) and the Hispanic Stress Inventory (HSI) were administered. Three explanatory models were evaluated. The first model tested the effect of demographic variables alone as predictors of MAST scores, the second tested the effects of stress and DRD2 genotypes separately, and the third tested the effect of the interaction between stress and the DRD2 genotypes. The first two models did not yield significant results; neither MAST scores nor HSI scores were found to be associated with DRD2 genotypes. However, model three confirmed a significant (p<.05) interaction between DRD2 genotype and the stress score as a predictor of MAST score. Additionally, this difference was found to be largely accounted for by the HSI occupational/economic stress score, which had a highly significant (p=.003) interaction with DRD2 genotype as a predictor of MAST score. The MAST scores of the participants that did not carry the DRD2 (A2A2) were found to be nearly identical in low stress and high stress participants, whereas the MAST scores of heterozygotic form of the DRD2 (A1A2) participants increased modestly with stress (p=.01) and that of homozygotic form of the DRD2 (A1A1) participants increased markedly (p=.001). These findings confirm the hypothesis that DRD2 genotype-phenotype associations depend upon the magnitude of stress exposure. The findings of this study will help health care professionals to identify individuals and populations at risk and to design appropriate prevention and treatment programs at all levels.
International Public Health, Alcoholism -- Honduras; Stress -- ethnology -- Honduras; Alcoholism -- etiology; Alcoholism -- genetics
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