In the largest functional brain imaging study to date, researchers have identified specific differences between the brains of females and males.
3D surface and midsagittal images illustrating regional sex differences in rCBF (regional cerebral blood flow). Image credit: Daniel G. Amen et al, doi: 10.3233/JAD-170432.
Lead author Dr. Daniel Amen, a psychiatrist and founder of Amen Clinics, Inc, and co-authors analyzed a healthy and very large psychiatric population to determine the effect of gender, using single photon emission computed tomography (SPECT).
They compared 46,034 brain SPECT imaging studies provided by nine clinics.
The sample included 119 healthy volunteers and 26,683 patients with a variety of psychiatric conditions such as brain trauma, bipolar disorders, mood disorders, schizophrenia/psychotic disorders, and attention deficit hyperactivity disorder (ADHD). A subset of 11,587 patients had complete diagnostic information.
A total of 128 brain regions were analyzed for subjects at baseline and while performing a concentration task.
“This is a very important study to help understand gender-based brain differences,” Dr. Amen said.
“The quantifiable differences we identified between men and women are important for understanding gender-based risk for brain disorders such as Alzheimer’s disease.”
“Using functional neuroimaging tools, such as SPECT, are essential to developing precision medicine brain treatments in the future.”
The brains of women in the study were significantly more active in many more areas of the brain than men, especially in the prefrontal cortex, involved with focus and impulse control, and the limbic or emotional areas of the brain, involved with mood and anxiety.
The visual and coordination centers of the brain were more active in men.
“Our results demonstrated significant gender differences in a healthy and clinical population,” the authors said.
“Understanding these differences is crucial in evaluating functional neuroimaging and may be useful in understanding the epidemiological gender differences among psychiatric disorders.”
“Women have significantly higher rates of Alzheimer;s disease, depression, which is itself is a risk factor for Alzheimer’s disease, and anxiety disorders, while men have higher rates of ADHD, conduct-related problems, and incarceration (by 1,400%),” they added.
The study finding of increased prefrontal cortex blood flow in women compared to men may explain why women tend to exhibit greater strengths in the areas of empathy, intuition, collaboration, self-control, and appropriate concern.
The study also found increased blood flow in limbic areas of the brains of women, which may also partially explain why women are more vulnerable to anxiety, depression, insomnia, and eating disorders.
The results were published online this month in the Journal of Alzheimer’s Disease.
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Daniel G. Amen et al. Gender-Based Cerebral Perfusion Differences in 46,034 Functional Neuroimaging Scans. Journal of Alzheimer’s Disease, published online August 4, 2017; doi: 10.3233/JAD-170432
