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People suffering from an alcohol dependency may see the production of an enzyme 'turned off' as the dependency grows, a group of scientists has found.

The enzyme, called PRDM2, is significantly decreased by a history of alcoholism and, as a result, it is claimed the 'knockdown' of the enzyme results in a greater alcohol consumption or a 'vicious cycle' of addiction.


Research, published in the journal Molecular Psychiatry, says that alcoholism sees the enzyme's creation stopped in the nerve cells of the brain's frontal lobe.

"PRDM2 controls the expression of several genes that are necessary for effective signalling between nerve cells," Markus Heilig from Linköping University, and leader of the study, says. "When too little enzyme is produced, no effective signals are sent from the cells that are supposed to stop the impulse".

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For the study, the researchers found that alcohol dependency in rats leads to a decrease in production of PRDM2.

The rats in the study were exposed to alcohol vapour for 14 hours each day, over a period of seven weeks – testing was approved by the National Institute on Alcohol Abuse and Alcoholism. For 'self-administration' of alcohol, the animals were trained to drink from water containing alcohol.

As a result of making the rats dependent on alcohol, the researchers say, the reduction of the enzyme caused a 'disruption' in the rodents' impulse control.


"This is why the laboratory animals continue to consume alcohol, even when it is unpleasant," a statement from the university says. "If they are subjected to stress, they also quickly relapse into drinking alcohol."

To test this theory, the researchers stopped the production of the enzyme in rats that weren't dependent on alcohol and found the impulse behaviour of the rats was also 'disrupted'.

"We see how a single molecular manipulation gives rise to important characteristics of an addictive illness," Heilig explained. "Now that we’re beginning to understand what’s happening, we hope we’ll also be able to intervene."