Although it has been suggested that brain functions in young men and women are changed by long-term alcohol use, new research discovers the changes are significantly different in men and women. The findings show that the risk of long-term harm from alcohol are increased in young people, with men possibly more at risk.
A Finnish research group worked with 11 young men and 16 young women who had heavy 10- year alcohol use, and compared them with 12 young men and 13 young women who had little or no alcohol use. All were between 23 to 28 years old at the time the measurements were taken.
The researchers examined the responses of the brain to being stimulated by magnetic pulses — known as Transcranial Magnetic Stimulation (TMS), which activates brain neurons. The brain activity was measured using EEG (electroencephalogram).
Previously, the researchers had found that heavy alcohol users showed a greater electrical response in the cortex of the brain than non-alcohol users, which indicates that there had been long-term changes to how the brain responds.
This time, they found that young men and young women responded differently, with males showing a greater increase in electrical activity in the brain in response to a TMS pulse.
“We found more changes in brain electrical activity in male subjects, than in females, which was a surprise, as we expected it would be the other way around. This means that male brain electrical functioning is changed more than female brains by long-term alcohol use,” said Dr. Outi Kaarre, University of Eastern Finland and Kuopio University Hospital, Finland.
The EEGs also allowed the researchers to show that male brains have greater electrical activity associated with GABA (gamma-amino butyric acid) neurotransmission than do female brains.
Said Kaarre, “Generally, our work showed that alcohol causes more pronounced changes in both electrical and chemical neurotransmission in men than women.”
There are two types of GABA receptors, A and B, Kaare said. Long-term alcohol use affects neurotransmission through both types in males, but only one type, GABA-A, is affected in females.
“We’re still trying to figure out what this means, but GABA is a pretty fundamental neurotransmitter in the inhibition of many brain and central nervous systems functions,” she said. “It’s involved in many neurological systems, and is important in anxiety and depression. Generally it seems to calm down brain activity.
“We know from animal studies that GABA-A receptor activity seems to affect drinking patterns, whereas GABA-B receptors seem to be involved in overall desire for alcohol. It has been suggested that women and men may respond differently to alcohol. Our work offers a possible mechanism to these differences.
“It may be that we need to look at tightening regulations on youth drinking, since none of our study participants met the diagnostic criteria for alcohol use disorders and still these significant changes in brain functioning were found. It may also mean that gender differences should be taken into account when planning pharmacological treatment for alcoholism.”
Experts believe the findings are important as young women are now drinking more.
“This may also mean that a different group of women is getting involved in early heavy alcohol use than used to be the case; in other words, when heavy drinking occurs more frequently and tends to become the norm, women do not need to have some aberrant personal characteristic to become an early heavy user of alcohol,” said Professor Wim van den Brink , Professor of Psychiatry and Addiction at the Academic Medical Centre, University of Amsterdam.
“These are very interesting findings, especially since young women are catching up with young men when it comes to drinking and heavy drinking in Europe. The finding of a different EEG-pattern in male and female early heavy drinkers may indeed have important consequences for the treatment of male and female patients with an alcohol use disorder.”
Study findings were presented at the European College of Neuropsychopharmacology (ECNP) meeting in Paris.