Alcohol can reduce our reactivity to stress, and a new experiment suggests that this effect is stronger for particular types of stressful situations. The findings, published in the journal Clinical Psychological Science, revealed that alcohol more strongly alleviates reactivity when stressors are uncertain — like the stress of receiving an electric shock of unknown intensity.
Previous studies have revealed that consuming alcohol can alleviate the stress response. It has been proposed that this effect encourages people to use alcohol as a stress-coping mechanism, which then reinforces alcohol intake and promotes addiction. It has also been suggested that this stress response dampening is stronger for specific types of stressors. Study author Daniel E. Bradford and his team say that establishing these types of stressors could help inform the prevention and treatment of alcohol use behavior.
“Our laboratory wants to improve mechanistic understanding of the psychological effects of stress and drugs,” explained Bradford, an assistant professor and principal investigator of the Biology and Emotion of Addiction Via Experimental and Reproducible Science (BEAVERS) Lab at Oregon State University.
“The topic of this manuscript interests us because it follows the theory that alcohol may affect responses to some types of stressors more than other types of stressors. More specifically, alcohol may affect responses to stressors that are in some way uncertain more so than stressors that are certain, regardless of how controllable those stressors seem. Because there are different psychological and neurological components to responding to uncertain versus other stressors, this has implications for exactly how alcohol affects stress as well as how the negative effects of alcohol and other drug consumption could be best dealt with.”
Bradford and his colleagues devised a study to test whether the certainty and controllability of a stressor modulates alcohol’s effects on reactivity. A total of 128 college-aged adults participated in the lab experiment. Depending on the condition, the participants were either given alcohol, no alcohol, or a placebo.
They then participated in a paradigm where they received electric shocks during blocks of trials that were either certain (a cue warned participants of the shock intensity) or uncertain (a cue provided a range of possible shock intensities), and either controllable (participants were told they could lower the intensity of the shocks) or uncontrollable (participants were told they could not control the intensity). The subjects self-reported their anxiety levels throughout the task.
Six noise probes were also presented throughout the trial, and the researchers measured participants’ eye-blink startle response. They also used electroencephalogram (EEG) recordings to measure brain responses to the startle probes, also called event-related potentials (ERPs). The researchers specifically focused on the suppression of the P3 ERP response, which served as a measure of emotionally-motivated attention.
The findings revealed that, in all stressor scenarios, alcohol significantly dampened subjective anxiety potentiation, startle potentiation, and probe P3 suppression. But for both anxiety potentiation and startle potentiation, this dampening effect was significantly greater for uncertain versus certain threats. By contrast, alcohol’s dampening effect remained the same for uncontrollable versus controllable stressors.
The findings indicate “that alcohol may not affect responses to all sort of stressors equally, and which types of stress responses alcohol effects may partly determine when alcohol will work best as a stress reliever,” Bradford told PsyPost. “Furthermore, people who use alcohol to deal with uncertain stressors (like being in public with strangers or going on a blind date) may find alcohol particularly reinforcing, and thus harder to abstain from using.”
The researchers note that it will be important for future studies to explore uncertain stressors that more closely resemble stressors in the real world, as opposed to the electric shock stressor. This would increase the generalizability, clinical relevance, and ecological validity of the findings.
“There are always major caveats in research,” Bradford said. “Some to note about this research is that it is based on translational experimental models which help us to understand things like neural mechanisms but this experimental situation may not generalize that well to everyday situations outside of the laboratory. For example, the stressors used in this laboratory story were threat of mild electric shock like is used in rodent research.”
“We still need to see how well these effects generalize to other types of stressors that may be more present in day-to-day life. Furthermore, while stressor uncertainty may be a potentially important aspect of the stressors when to comes to drug use, it is almost certainly not the only one. We still need to rule out other aspects of stressors like how long they last.”
“I will note that the data processing and analysis parameters of this study were preregistered, which can help you trust the statistical results,” Bradford added. “Preregistration helps guard against any unintentional (or intentional) messing around with the processing and analysis to try and get an outcome that the researchers want. You can learn more about this by reading about the Replication Crisis, the Open Science Movement or the Reproducibility Revolution.”
The study, “Alcohol’s Effects During Uncertain and Uncontrollable Stressors in the Laboratory”, was authored by Daniel E. Bradford, Jack M. Shireman, Sarah J. Sant’Ana, Gaylen E. Fronk, Susan E. Schneck, and John J. Curtin.
