Effects of Stress on Alcohol Consumption

Animal Studies. Animal studies of the effects of stress on drinking behavior have used three types of stressors: shock, restraint, and psychological stressors such as isolation and dominance, sleep deprivation, and early weaning and handling. Alcohol ingestion has been measured during the stressor administration, on the day of the stressor, or on the days following the stressor.

Studies using laboratory animals have found that both physical and psychological stressors are associated with an increased tendency to develop a pattern of drug or alcohol use. One explanation for this relationship is that stress increases the reinforcement properties of drugs, perhaps by increasing glucocorticoid secretion, which in turn may enhance the drug-induced release of dopamine.

Across a number of studies, it appears that the probability of alcohol ingestion is especially enhanced following the termination of a stressor. This may be accounted for in part by the ability of alcohol ingestion to replenish endogenous opiate levels that may become depleted during periods of stress. Studies also suggest that a number of factors may affect the relationship between stress and drinking in animals.

Individual differences in preference for alcohol may affect the stress-alcohol interaction, with stress particularly likely to increase subsequent drinking among animals that have low initial preference for alcohol. Another difference that has been observed concerns neonatal experience, with rats that were weaned earlier showing increased alcohol consumption. Genetic factors have also been implicated as moderators of the effects of stress on alcohol ingestion, with various strains of mice ingesting different amounts of alcohol following stress.

Human Studies. In the 1940s, cross-cultural studies led to the proposal that societies that experienced the most stress were also the societies with the highest per capita levels of drinking. To examine whether stress precipitates alcohol consumption in humans, both survey and experimental studies have been conducted.

A number of retrospective studies have examined the relationship between stress and drinking. These studies indicate a modest increase in drinking (as well as a modest increase in heavy drinking) following stress. This effect may be influenced by a host of individual difference factors, including ethnicity, gender, and age.

Prospective studies have accumulated that assess both drinking and stress over specified time periods. These studies generally reveal a tendency for stress levels to correlate with drinking levels. Further, in many instances, individuals appear to drink in order to cope with stress.

In addition to survey research, experiments have been designed to test the causal relationship between stress and drinking. Often these studies first expose participants to some form of stressor (e.g., threat of shock, a stressful social interaction, or false performance feedback). Next, their alcohol intake is assessed while they participate in what is ostensibly a wine or beer taste-rating task.

The critical dependent measure, unbeknown to participants, is the quantity of alcohol consumed. Data from these tasks have been inconclusive. Some studies have found clear effects, such that individuals who were stressed consumed more alcohol than their nonstressed counterparts. Other studies have failed to observe this pattern, and in some cases the reverse has been found, with stress leading to a reduction in drinking. As previously noted with respect to animal research, it may be that drinking is especially likely to increase after the stressor has terminated.

Another issue that may obfuscate the findings with human participants is the varied approaches to inducing stress. In some cases, for example, it is unclear just how effective the stressors were. In summary, while laboratory studies have been equivocal, findings from survey research suggest that increases in stress are associated with increased alcohol consumption.