What was once speculation is now being confirmed by scientists: the brains of women and men are different in more ways than one.
Discoveries by scientists over the past 10 years have elucidated biological sex differences in brain structure, chemistry and function. “These variations occur throughout the brain, in regions involved in language, memory, emotion, vision, hearing and navigation,” explains Larry Cahill, Ph.D., an associate professor in the Department of Neurobiology and Behavior at the University of California, Irvine.
While women and men struggle to communicate with each other and ponder why they don't think and react to things in similar ways, science is proving that the differences in our brains may have more serious implications beyond our everyday social interactions.
Scientists are looking into ways that sex-based brain variations affect the thought processes and behavior of men and women differently. According to Cahill, “their discoveries could point the way to sex-specific therapies for men and women with neurological conditions such as Alzheimer's disease, schizophrenia, depression, addiction and post-traumatic stress disorder.”
To better understand the implications of sex differences in the brain, it is important to examine disease entities in depth. Take Alzheimer's disease, for example. Significant differences exist between men and women who suffer from the disease.
“There are growing indications that the disease pathology, and the relationship between pathology and behavioral disturbance, differs significantly between the sexes,” Cahill wrote in a paper published in Nature Reviews Neuroscience. Pathology refers to the way a disease develops within the body.
“Let us first consider Alzheimer's disease-related pathology. Alzheimer's disease-related neurofibrillary pathology associated with abnormally phosphorylated tau protein differs in the hypothalamus of men and women: up to 90 percent of older men show this pathology, whereas it is found in only 8-10 percent of age-matched women.”
In other words, abnormalities caused by Alzheimer's disease may differ between the sexes and result in different symptoms or behavioral problems for women and men with the disease.
There are several other notable differences in pathology between the sexes in Alzheimer's disease. Gaining a better understanding of the relationship between pathology and how disease presentation affects men and women differently could pave the path for future sex-specific therapies.
Schizophrenia is another disease that affects men and women differently. Differences include age of onset, symptoms and the time course of the disease. In addition, structural brain differences are apparent. According to Cahill, “men with schizophrenia show significantly larger ventricles than do healthy men, whereas no such enlargement is seen in women with schizophrenia.”