Stress and alcohol drinking.

The concept of stress-relief by alcohol has led to many investigations in order to elucidate the mechanisms of interactions of stress and alcohol, and the stress-reducing effect of alcohol as a motivation for alcohol consumption. The hypothalamo-pituitary-adrenocortical (HPA) system is one of the biological systems affected by both stress and alcohol. However, there is a high individual variation in the response of the HPA axis to either stress or alcohol. Factors like quality, severity and duration of stress, dose of alcohol and frequency of stress or alcohol exposure add to the individual response to stress or alcohol. The individual response is determined by interactions of genetic, environmental and experiential factors. Facing that complexity, with even more factors to be named, the often reported inconsistencies in both human and animal studies are not only attributable to methodological differences. Nevertheless, there are studies showing an influence of stress on alcohol consumption which most likely depends on the sample of probands examined. To our view, the concept of stress-relief by alcohol as a basic motivation for developing alcohol drinking habits is only applicable to subgroups of drinkers. Individuals with a dysfunctional HPA axis, inherited and/or acquired, might represent such a subgroup of stress-motivated drinkers.