Lack of Enzyme in the Brain May Be Tied to Alcohol Addiction

Alcohol Addiction

A recently published study has discovered an enzyme in the brain that researchers believe affects impulse control. The enzyme is not produced in patients suffering from alcohol addiction, which could lead to continued alcohol abuse in the face of negative consequences.

The idea that alcoholism or other forms of addiction are tied to impaired brain function—specifically the frontal lobe—is not new, but the underlying mechanism for the effect has remained unknown. The researchers, from Linköping University, believe they have identified an enzyme, PRDM2, which is behind the phenomenon.

PRDM2 governs various gene expressions that strengthen signals between nerve cells in the frontal lobe. These signals are what help regulate and stop impulsive behavior: too little PRDM2 and these signals don’t get sent, making impulses harder to resist.

Alcohol Dependency Reduces PRDM2 Production

The researchers directed their study towards rats and found that alcohol dependency reduced PRDM2 production. This limited production, in turn, was associated with a reduction in impulse control. The affected rats continued drinking alcohol even in the face of negative consequences; which in this case meant alcohol that had been tainted with foul-tasting quinine. When subjected to stress, the rats also quickly relapsed.

In another experiment, the researchers knocked out PRDM2 in the frontal lobes of rats that did not have an alcohol dependency. Despite not being alcohol-dependent, the rats still displayed impulse control problems.

The idea that an enzyme deficiency in the brain could be inhibiting those recovering from alcohol addiction is an interesting idea and needs to be explored more. In the long term, probing the topic for how PRDM2 affects different types of addiction, how or why drinking alcohol disrupts production, and whether new medical treatments for addiction could be developed are all potential avenues of inquiry. In the short term, the researchers are hoping that their finding helps reduce some of the stigma associated with alcoholism.

Barbier, E., et. al., “Dependence-induced increase of alcohol self-administration and compulsive drinking mediated by the histone methyltransferase PRDM2,” Molecular Psychiatry, 2016; 10.1038/mp.2016.131.