lop (assuming that the changes were a product and not a cause of the heavy drinking). It’s still not totally clear how the changes translate into behaviors like craving, dependence, or abstention, but the researchers have some early guesses.
The study has not been published in a peer-reviewed publication yet, so should be considered preliminary.
The participants were 11 men and 16 women between the ages of 23 and 28 years old who did not criteria for alcohol use disorder, but all reported drinking patterns over the previous 10 years or so that put them into the category of “heavy” drinkers. People who reported little or no alcohol use served as controls.
The team measured the electrical and chemical activity in the participants’ brains, and found some disparities between the men and women who were heavy drinkers. In particular, there were differences in the activity of receptors for the neurotransmitter GABA, which is generally responsible for inhibiting brain activity, and is important for regulating anxiety (its receptors are what benzodiazepines bind) and is thought to play a role a role in depression.
“Generally, our work showed that alcohol causes more pronounced changes in both electrical and chemical neurotransmission in men than women,” said study author Outi Kaarre in a statement. “There are two types of GABA receptors, A and B. Long-term alcohol use affects neurotransmission through both types in males, but only one type, GABA-A, is affected in females.” She added that this was the opposite of what the team expected to see.
Animal studies have suggested that the GABA-A receptor activity may influence drinking patterns, while GABA-B is connected to desire for alcohol, according to the researchers. The fact that both types of receptor were affected in men in the current study may shed some light, for one, on the role medications may play in treating alcohol dependence: If only one type of receptor is affected in women, for instance, this could help explain why drugs like Baclofen, which only targets GABA-B receptors, have had mixed results. And beyond meds, the differences in brain response between men and women may help clinicians understand more about what drives each sex to heavy drinking in the first place, how they react to alcohol, and why they develop dependence.
According to the NIH, men are nearly twice as likely as women to have alcohol use disorder, and research has suggested that men are more likely to binge drink and to drink heavily. But it seems that women’s drinking has largely caught up to men’s in recent years: Research last year found that the gender gap in alcohol use has decreased, with women’s use approaching that of men. And a study last month found that people are in general drinking more than they were 10 years ago, with women’s alcohol use rising especially fast, for a variety of reasons.
An important caveat to the new study is that it’s possible that the brain differences existed before the drinking, not because of it. But other studies have certainly found gender differences in alcohol use, and in its effects on the brain, which can be devastating over time. It’s likely a two-way street. Much more needs to be done to understand how the brain reacts to alcohol, in the short and the long term, in both women and men. In the meantime, drinking only lightly if you already do, cutting down if you drink heavily, and not starting if you don’t drink seems to be the best advice.