For centuries, people have suspected that there are more differences between men and women than what can be seen on the outside. Eventually, we were able to understand that these gender differences exist even in the physiology of male and female brains. A new study has uncovered when these differences occur, and it may help to explain how gender can make you more susceptable to certain psychiatric disorders.

During puberty our bodies and brains undergo a number of changes as we transition from childhood into adulthood. Among these changes is a shift in the amount of cerebral blood flow (CBF) in our brains. In a recent study, researchers discovered that during puberty the CBF changes in contrasting ways for young men and women, Medical News Today reported. Researchers found that at age 16, male CBF declined while female CBF increased. By the time adolescence ends, women have a much higher CBF than males.

This difference was greatest in the orbitofrontal cortex, the area of the brain that controls social behavior and emotional regulation. "These findings help us understand normal neurodevelopment and could be a step towards creating normal 'growth charts' for brain development in kids. These results also show what every parent knows: boys and girls grow differently. This applies to the brain as well," Dr. Satterwaite, lead researcher on the study explained to Medical News Today.

These differences in CBF may explain why there are higher risks of depression and anxiety disorders for women, and higher risk of schizophrenia in men, Medical News Today explained. The researchers also believe that these differences may explain why women frequently out-perform men on social cognition tasks.

Before this study, the exact physiology of brain developments during puberty were not researched in depth. It was known that adult women had higher blood flow than men, but what researchers did not know was when this difference in CBF occurred. “We hypothesized that the gap between women and men would begin in adolescence and coincide with puberty,” said Satterwaite, explaining the motivation behind his study. The team used an MRI to image the brains of over 900 young adults between the ages of 8 and 22. All of the volunteers were members of the Philadelphia Neurodevelopmental Cohort, Science World Report explained.

The World Health Organization defines gender as a critical determinant of mental health and mental illness. Although mental disorders will affect men and women the same, there are observable gender differences found in those who suffer from certain conditions. The WHO lists gender differences such as men being three times as likely to be diagnosed with antisocial personality disorder than women and depression being more persistent in women than men.

Source: Satterthwaite TD, Shinohara RT, Wolf DH, et al. Impact of puberty on the evolution of cerebral perfusion during adolescence. Proceedings of the National Academy of Sciences of the United States of America. 2014.