Gender Differences in the Brain Explain Why Men Have Higher Rates of ADHD

The brains of women are significantly more active than the brains of men, according to the largest functional brain imaging study to date conducted by Amen Clinics. This explains why there are higher rates of some conditions, such as attention-deficit/hyperactivity disorder (ADHD), in men compared with women, who have higher rates of depression.

The study, published by the Journal of Alzheimer’s Disease, attempted to quantify the differences between the brains of men and women by comparing 46,034 brain single photon emission computed tomography (SPECT) imaging studies from 9 clinics.

The researchers found that the brains of women were more active in more areas of the brain than the brains of men. For instance, a woman’s brain demonstrated more activity in the prefrontal cortex, which involves focus, impulse control, and the limbic or emotional areas of the brain, including mood and anxiety. However, the visual and coordination centers of the brain were more active in the brains of men.

“This is a very important study to help understand gender-based brain differences. The quantifiable differences we identified between men and women are important for understanding gender-based risk for brain disorders such as Alzheimer’s disease,” lead author, psychiatrist Daniel G. Amen, MD, founder of Amen Clinics, Inc., said in a statement. “Using functional neuroimaging tools, such as SPECT, are essential to developing precision medicine brain treatments in the future.”

The study analyzed 128 brain regions of 119 healthy volunteers and 26,683 participants with psychiatric conditions including brain trauma, bipolar disorders, mood disorders, schizophrenia/psychotic disorders, and ADHD, while the participants performed a concentration task.

Through the use of SPECT, the images showed an increase of blood flow in women compared to men, especially in the cingulate gyrus and precuneus, while men had higher blood flow in the cerebellum. Furthermore, women had a significantly greater rate of Alzheimer’s disease and depression, while men had higher rates of ADHD, conduct-related problems, and incarceration.

“Precisely defining the physiological and structural basis of gender differences in brain function will illuminate Alzheimer’s disease and understanding our partners,” stated George Perry, PhD, the editor-in-chief of the Journal of Alzheimer’s Disease and dean of the College of Sciences at The University of Texas at San Antonio.