Compulsive alcohol consumption wired differently in the brain

Is compulsive alcohol consumption wired differently in the brain?  Social drinking can be defined by the level of choice and the nature of the choice to drink alcohol.    Social drinkers drink with others.  It involves parts of the brain that underpin habits, but allow us to make free choices.

But what about compulsive drinking?  Are different areas of the brain activated in compulsive drinkers?  The answer it seems is yes.

Visual alcohol cues for heavy drinkers activate an area of the brain called the dorsal striatum.  In social drinkers it is the ventral striatum that is activated.  This suggests different brain circuits are at work in heavy, compulsive alcohol drinkers.

Heavy alcohol drinkers attempt to acquire alcohol despite the threat of a negative consequence more so than light drinkers, a study published in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging has found, and this behaviour is associated with unique activation of brain circuitry in heavy drinkers.

"Compulsivity circuit"

The findings provide evidence for a “compulsivity circuit” that may drive alcohol-seeking behaviour that is resistant to negative consequences.

First author Dr Erica Grodin and her colleagues designed a task to assess compulsive behaviour of heavy and light drinkers. In contrast to habits—which drive behaviour automatically even when it’s no longer rewarding—compulsive behaviour continues despite negative consequences.

In the task, participants could risk receiving a painful electric shock to earn points for alcohol or food.

Heavy drinkers chose alcohol reward despite risks

Heavy drinkers tried to earn alcohol despite the risk for shock, whereas light drinkers tended to not take the risk. Both groups were willing to seek alcohol and food rewards when there was no threat of a shock.

Previous studies have used animal models.  As lead author Erica Grodin tells us
This study is important because it is the first study to investigate compulsive alcohol seeking in a heavy drinking population. 

Brain function and compulsivity 

Prefrontal cortical regions and the insula are thought to play a role in compulsive behaviour because of their role in decision-making under conflict.  The current study confirmed these regions are involved in compulsive drinking. 

Brain imaging conducted during the task revealed that heavy drinkers had more activity in brain regions associated with decision-making under conflict—the anterior insula and prefrontal cortex—and with habit and reward—the striatum. Imaging also revealed functional connections between two brain regions that were stronger in people with stronger compulsivity.
This study highlights the complex rewiring that takes place in the heavy drinker's brain. Circuitry associated with conflict, risk and aversion become associated with those that process rewarding experiences, and this is associated with increased risky choice behaviour when alcohol is a possible reward.

Subscribe to The Thin End

Comments

Popular Posts