Study Suggests Breakthrough in Tackling Alcoholism – Normalizing Dopamine Levels in the Brain Can Reduce Alcohol Cravings, Study Shows?xml:namespace prefix = o ns = “urn:schemas-microsoft-com:office:office” /
More than 16 million adults in the U.S. have an alcohol-use disorder
By Gautam Naik
Oct. 14, 2015
Scientists have shown that a drug that normalizes dopamine levels in the brain can reduce alcohol cravings in people dependent on drink.
The finding was based on two studies, one conducted on people and one on rats. In the human trial, patients who took the experimental drug showed a marked reduction in alcohol craving. A separate animal study suggested that the drug works by acting on dopamine levels.
“It is proof of concept” that alcohol dependency can be treated by targeting the dopamine system, said Pia Steensland, neuroscientist at Karolinska Institute in Sweden and co-author of both studies. “We need to do larger trials” to validate the results.
Current drugs for alcohol dependency aren’t especially effective. The population of patients is genetically diverse, so only certain subgroups benefit. Prescription rates are low. As a result, the need for better medicines is huge.
Alcohol makes the brain’s reward system release more dopamine than normal, triggering a feeling of well-being. But as more alcohol is drunk, the more the reward system is desensitized and the less dopamine is released. Eventually, a person drinks more alcohol not just to feel euphoric, but to attain a state of physical and emotional normality. Thus, addiction sets in.
More than 16 million adults in the U.S. have an alcohol-use disorder and nearly 88,000 people die each year from alcohol-related causes, according to the National Institutes of Health. In 2006, alcohol misuse cost the U.S. economy $223.5 billion, the NIH said.
For the human study, published Wednesday in the journal European Neuropsychopharmacology, scientists recruited 56 Swedish alcohol dependent men and women, who typically would drink the equivalent of a bottle of wine a day.
The participants abstained from drink for at least four days. Half were then given a placebo and half got OSU6162, a drug believed to stabilize dopamine levels. The patients were randomized and neither they nor the researchers knew who was getting the experimental drug and who was getting the placebo.
For two weeks, the participants could drink as much as they liked. On day 15, each person was offered a glass of their favorite drink. According to the study, the OSU group reported not enjoying their first sip as much as the placebo group. After the drink was finished, the OSU group reported a lower craving for alcohol compared to the placebo group.
In addition, those with the poorest impulse control-and thus at greater risk of relapse after a period of abstinence-responded best to the experimental drug.
Both the OSU and placebo groups reported only mild side effects. This is significant because other dopamine-based medicines, such as those used to treat schizophrenia, completely block dopamine and can lead to nasty side-effects, such as nausea.
The rights to OSU6162 are owned by Arvid Carlsson, professor emeritus at the Sahlgrenska Academy in Sweden and co-author of the human study. Dr. Carlsson, 92 years old, shared in the 2000 Nobel Prize for medicine for discovering that dopamine is a transmitter in the brain. His team also developed OSU6162.
To better understand how OSU6162 might work, Dr. Steensland and other researchers did a separate study on rats, also published Wednesday in the journal Addiction Biology. Rats that voluntarily drank alcohol over the course of almost a year had lower dopamine levels than animals that drank no alcohol. When OSU6162 was given to the “alcohol rats,” their dopamine levels returned to normal.
The human trial wasn’t designed to comprehensively evaluate whether the experimental drug could help people drink less. But because of the promising early-stage results, Dr. Steensland and her colleagues now hope to do a longer-term trial involving many more patients.