Researchers at Massachusetts General Hospital (MGH) and Boston University School of Medicine (BUSM) used brain MRIs in a new study to find the effects of alcoholism on the brain’s reward system may be different in women and men.
The study was designed to test whether differences in the alcoholism-associated reward system previously observed in men would have the same effects in women.
"Until now, little has been known about the volume of the reward regions in alcoholic women, since all previous studies have been done in men," said co-author Gordon Harris, PhD, of the 3D Imaging Service and the Center for Morphometric Analysis in the Martinos Center for Biomedical Imaging at MGH in a statement. "Our findings suggest that it might be helpful to consider gender-specific approaches to treatment for alcoholism."
The study, published in Psychiatry Research Neuroimaging, enlisted 30 men and 30 women with histories of long-term alcoholism and 60 nonalcoholic volunteers. The alcoholic patients had been abstinent for anywhere between four weeks to 38 years. Each patient completed detailed medical histories and neuropsychological assessments prior to having brain MRIs that were analyzed in terms of the total brain and structures in the reward network.
The researchers replicating the results of earlier studies, finding the average size of the reward region structures of alcoholic men were 4.1 percent smaller than those of nonalcoholic men. When it came to alcoholic women, the average sizes of the reward region structure were 4.4 percent larger than nonalcoholic women. The duration and intensity of heavy drinking may have played a role in gender-specific effects.
The researchers, however, found that the current study was unable to determine whether these differences preceded or resulted from the development of alcoholism. For both alcoholic men and women, each year of sobriety was linked with a 1.8 percent decrease in the size of the ventricles, suggesting recovery from the damaging effects of alcoholism on the brain.
"We're planning to take a more detailed look at the impact of factors such as the severity of drinking and the length of sobriety on specific brain structure, and hope to investigate whether the imaging differences seen in this and previous studies are associated with gender-based differences in motivational and emotional functions," said co-author Marlene Oscar-Berman, PhD, a professor of psychiatry, neurology, anatomy and neurobiology at BUSM.