Lead study author Dr. Daniel G. Amen, of Amen Clinics, Inc. in Newport Beach, CA, and colleagues recently published their findings in the Journal of Alzheimer’s Disease.
When it comes to brain-related disorders, men and women are often disproportionately affected. For example, according to the Alzheimer’s Association, around 5.5 million people in the United States are living with Alzheimer’s disease. Of these individuals, around two thirds are women.
Studies have also found that women are almost twice as likely as men to develop depression over the course of a lifetime.
Many developmental disorders – such as autism and attention deficit hyperactivity disorder (ADHD) – however, are more common in males. According to the Centers for Disease Control and Prevention (CDC), autism is around 4.5 times more common in boys than girls.
But what are the reasons behind these sex disparities? According to Dr. Amen and team, it may be down to differences in brain activity.
Higher brain activity for women
The researchers came to their findings by analyzing brain scans from 119 healthy men and women, as well as 26,683 men and women who had been diagnosed with a psychiatric condition, such as ADHD, bipolar disorder, or schizophrenia.
Brain images for each participant were taken using single photon emission computed tomography (SPECT), a type of functional imaging technique that measures blood flow in specific brain regions, which is a good indicator of activity in that region.
SPECT imaging was conducted at study baseline and during a concentration task. In total, 128 brain regions were analyzed.
The study revealed that women showed much higher brain activity in more brain regions than men. For instance, at study baseline, their brain activity was increased in 65 brain regions, compared with only nine brain regions for men. During the concentration task, women showed increased activity in 48 brain regions, while men showed increased activity in just 22 brain regions.