Alcohol addiction is a widespread mental health issue, affecting individuals globally. Males are more prone to showing symptoms of addiction. In addition, recent research highlights important sex-based differences in alcohol consumption, especially under conditions of stress. Sex differences are relevant since disorders like post-traumatic stress disorder often co-occur with alcohol abuse, but exactly how stress and alcohol influence behavioral responses of both sexes is still unclear. A study in Behavioural Brain Research examines how chronic ethanol exposure and traumatic stress impact male and female Wistar rats, using a Pavlovian fear conditioning paradigm to analyze avoidance responses to threats.

Researchers first exposed the rats to ethanol vapor over several days, inducing addiction as shown by withdrawal symptoms. Following this step, the rats underwent a single prolonged stress protocol involving physical restraint and forced swimming to simulate traumatic stress. After the stress exposure, the researchers assessed the rats’ conditioned fear responses and their capacity for fear extinction. During fear conditioning, control females displayed lower freezing levels than males, showing less passive fear behavior. A similar pattern emerged during the fear extinction phase, with females again showing more active responses. Females displayed smaller alcohol consumption and fewer withdrawal symptoms compared to males.

When examining how alcohol and trauma exposure impacted fear conditioning, results indicated no major effects on conditioned fear in either sex. Males exposed only to alcohol (without a traumatic experience) demonstrated a more active response compared to control males, exhibiting reduced freezing behaviors.

Although prior exposure to alcohol and stress had minimal effects, mice demonstrate a clear sexual dimorphism in threat responses: females tend toward active avoidance strategies, while males exhibit more passive responses. Recognizing these sex-specific behavioral responses is essential for designing future experiments to understand and treat mental health disorders.

Original reference: Mayberry, H.K., Rinker, J.A. and Chandler, L.J. Behav. Brain Res. 477, 115294 (2025)