The largest study to date of blood flow in the brain, conducted by 2010 NARSAD Young Investigator Grantee Theodore Satterthwaite, M.D., and a University of Pennsylvania team, has established for the first time that there are significant differences in how brain blood flow evolves during adolescence in males and females. These differences, reported online in the Proceedings of the National Academy of Sciences on May 27th, may have important implications in regard to neuropsychiatric disorders with adolescent onset and strong gender disparities, such as mood disorders, anxiety disorders, and schizophrenia.
Blood perfusion, the process of blood delivery to tissues, is fundamental to the physiology of all organs, and especially important for brain function. Cerebral blood flow was known to be greater in adult females than in males, but just when these sex differences emerge or what biological processes cause them has not been known.
For the current study, which was supported in part by the Brain & Behavior Research Foundation, the researchers examined MRI brain scans of 922 youths between the ages of eight and 22. The youths were participants in the Philadelphia Neurodevelopmental Cohort, a collaborative effort of the Brain Behavior Laboratory at the University of Pennsylvania and the Center for Applied Genomics at the Children’s Hospital of Philadelphia. The research team included Raquel E. Gur, M.D., Ph.D., and Ruben C. Gur, M.D., co-recipients of the Foundation’s 2009 Lieber Prize for Outstanding Achievement in Schizophrenia Research, and 2005 NARSAD Young Investigator Grantee Daniel H. Wolf, M.D., Ph.D.
While cerebral blood flow declines in early adolescence at a similar rate in males and females, the study found that in mid-puberty it continues to decline in males while rising in females, and that the disparity is specifically associated with the events of puberty, such as hormonal changes.
The researchers state that these results “have potential relevance to a wide range of psychiatric disorders that often manifest following puberty and have marked sex disparities, including depression, anxiety disorders and schizophrenia. Future research could test the hypothesis that increased perfusion in postpubertal females may be linked to the greater risk in females for mood and anxiety disorders and a lower risk of schizophrenia.”