Here's how stress-booze combo messes with your head

Many people think that necking a cocktail will help them relax, but it turns out the relationship between stress and booze is a two-way street.

Drinking alcohol results in an alcohol use disorder (AUD) when consumption becomes excessive and dependence develops. Both stress and anxiety can contribute to the development of an AUD. Chronic stress can increase drinking, and chronic drinking can elevate anxiety and dysregulate normal responses to stressors.

Behavioural flexibility and adaptive behaviour - essential for controlling excessive drinking - are core functions of the prefrontal cortex (PFC), this study used mice to examine the effects of combined alcohol and stress exposure on PFC function.

Researchers trained adult male mice to drink alcohol (15% v/v) on a one-hour-per-day/one-bottle schedule.

Once their drinking was stable, mice were exposed to cycles of chronic intermittent alcohol or air vapor, followed by test cycles of one-hour-per-day drinking. Four hours before each test, the mice were exposed to either no-stress, or 10 minutes of forced swim stress.

After two cycles of exposure, the study authors assessed PFC-dependent cognition, and at the end of the study, the mouse brains were examined for markers of neural activity.

The researchers found evidence of rapid disruptions in signaling across cognitive networks and impairments in two tests of PFC-dependent cognitive function in mice exposed to both alcohol and stress.

Identifying the cognitive consequences of stress and alcohol may make it possible to develop treatments for AUD that work by restoring cognitive control over drinking behaviour.

Future research should examine gender-specific changes in cognition and neural function associated with the interaction of alcohol and stress, as demonstrated in male mice here.

The study appears in journal Alcoholism: Clinical and Experimental Research.