Alcohol Use Disorder: A Step Toward Treatment?

Posted on February 13, 2019

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Alcohol Use Disorder (AUD) is characterized and diagnosed in an individual when their use of alcohol becomes compulsive and reaches a level that results in dysfunction to their daily lives. These individuals tend to feel intense cravings for alcohol and experience extreme withdrawals when they do not get their fix. Mood disorders such as depression and bipolar disorder have been evidenced to show links with AUD with the former being more prevalent. With regards to the link between the two, there has been difficulty to tease apart the directionality of cause and effect where drinking alcohol excessively can result in depression-like symptoms as alcohol alters mood, while those with mood disorders may turn to excessive consumption of alcohol as a form of self-medication.

This led to a team of researchers from the Oregon Health and Science University in Portland to study a zinc-binding receptor known as the G-protein coupled receptor 39 (GPR39) that has been linked to depression to investigate AUD. The study was initially conducted with animals first as interpersonal differences in level of alcohol consumption was not something unique to humans. The first used rhesus macaques and found that those with a natural propensity to consume more alcohol had reduced GPR39 activity. This led them to theorize the possibility that enhancing GPR39 activity might reduce alcohol intake.

Presently, there is a commercially available chemical, the TC-G 1008 that binds and activities GPR39. These researchers then gave this drug to the rhesus macaques and found that the increased GPR39 activation significantly reduced the amount of alcohol they consumed by 47%. The drug did not affect their behavior in any other way or their overall fluid intake, and repeated consumptions also kept alcohol consumption to a lower level. When this drug was flushed out of their system, their alcohol consumption levels reverted to its pretreatment levels. Furthermore, researchers also found a positive correlation with GPR39 and glutamate activity in the nucleus accumbens. Glutamate is the primary excitatory neurotransmitter in the brain and is involved in reward and reinforcement, and previous study has indicated its implication in alcohol misuse as well. Thus, researchers believed how the TC-G 1008 affected alcohol consumption was due to the changes in levels of excitatory and inhibition in the nucleus accumbens brought about by the drug.

With the promising result from the animal study, the next step for these researchers would be to replicate the study but with humans instead to examine if the same mechanism could apply. Results for this have yet to be concluded but it is a step towards finding a commercially available compound that could eliminated a fraction of the urges associated with AUD as currently there are only a limited number of approved drugs for alcoholism. Researchers hope that by modulating levels of GPR39, they would be able to devise new methods of treatment for both AUD and mood disorders, two disorders that at present pose a great difficulty to treat effectively.

Category(s):Addictions, Depression, Mood Swings / Bipolar

Source material from Medical News Today