Why alcohol makes people violent

The mystery of why alcohol makes people violent has finally been solved.

Scientists recruited 50 young men and asked them to consume either vodka or placebo drinks which were alcohol free.

They found that after just two drinks activity diminished in the prefrontal cortex of the brain – an area, which is involved in tempering a person’s level of aggression.

Although experts had suspected for some time that the prefrontal cortex was involved, it is the first time it has been seen happening.

The research was published in the journal Cognitive, Affective & Behavioural Neuroscience.

Dr. Thomas Denson of the University of New South Wales in Australia, said: “Although there was an overall dampening effect of alcohol on the prefrontal cortex, even at a low dose of alcohol we observed a significant positive relationship between dorsomedial and dorsolateral prefrontal cortex activity and alcohol-related aggression.

“These regions may support different behaviors, such as peace versus aggression, depending on whether a person is sober or intoxicated.”

To find out the real-time effects of alcohol on the brain, scientists used magnetic resonance imaging (MRI) scans that measure blood flow and show which areas are most active.

Participants were given alcohol or placebo then asked to complete a provoking task while lying in the scanner to gauge their levels of aggression.

Being provoked was found to have no influence on participants’ neural responses.

However, when behaving aggressively, there was a dip in activity in the prefrontal cortex of the brains of those who had consumed alcoholic drinks.

This dampening effect was also seen in the areas of the brain that are involved reward. Also, heightened activity was noted in the hippocampus, the part of the brain associated with people’s memory.

“We encourage future, larger-scale investigations into the neural underpinnings of alcohol-related aggression with stronger doses and clinical samples,” added Denson.

“Doing so could eventually substantially reduce alcohol-related harm.”