Alcohol addiction ruins millions of lives every year, but scientists may have found a cure for this terrible affliction.
A new treatment for alcohol use disorder (AUD) has been trialled in monkeys with impressive results and, if these translate to human trials, the impact could be monumental.
A team of neuroscientists and physiologists from across the US tested a new type of gene therapy to see if they could directly target the underlying brain circuitry associated with sustained heavy drinking.
As they noted, in the journal Nature Medicine, people suffering from AUD commonly return to alcohol use even if they attempt to quit.
This is largely to do with what’s known as mesolimbic dopamine (DA) signalling – meaning how the central nervous system circuit communicates the feelgood neurotransmitter dopamine.
A protein called glial-derived neurotrophic factor (GDNF) is key to keeping these neurons in this reward circuitry functioning.
However, experts have found that levels of GDNF are reduced in people with AUD during periods of alcohol abstinence, most notably in a region of the brain called the ventral tegmental area (VTA), as IFLScience notes.
Therefore, the researchers decided to test whether using gene therapy to deliver more GDNF to the VTA could help reinforce this crucial dopaminergic signalling and prevent patients from suffering an alcoholic relapse.
Levels of GDNF were found to be lower in people with AUD during periods of alcohol abstinenceiStock
The team of scientists explained how alcohol consumption in non-addicts prompts the release of dopamine, creating a pleasurable buzz feeling, but chronic alcohol use causes the brain to adapt and stop releasing so much dopamine.
“So when people are addicted to alcohol, they don’t really feel more pleasure in drinking,” Dr Kathleen Grant, a senior co-author of the study, said in a statement.
“It seems that they’re drinking more because they feel a need to maintain an intoxicated state.”
For their research, Dr Grant and her colleagues used eight rhesus macaque monkeys, who were exposed to increasing concentrations of alcohol over four 30-day “induction” periods.
The monkeys then had free access to alcohol and water for 21 hours a day for six months, during which they developed heavy drinking behaviours.
This was then followed by a 12-week abstinence phase, with the GDNF treatment performed four weeks in for half of the subjects.
The gene therapy was delivered using a a viral vector containing a copy of the human GDNF gene injected directly into the primate’s VTA, according to IFLScience.
And the results were truly jaw-dropping.
“Drinking went down to almost zero,” Dr Grant said. “For months on end, these animals would choose to drink water and just avoid drinking alcohol altogether. They decreased their drinking to the point that it was so low we didn’t record a blood-alcohol level.”
AUD affects a staggering number of adolescents even though they legally shouldn't be able to drinkiStock
The most exciting aspect of their findings is the suggestion that gene therapy could offer a permanent solution for people with the most severe cases of AUD.