Brain differences between sexes get more pronounced from puberty

"Researchers studying brain-imaging data from people aged between 8 and 100 found that sex differences in the brain's connections are minimal in early life, but then increase drastically at puberty; some of these differences continue to grow throughout adult life. The study was published as a preprint on bioRxiv, and has not yet been peer reviewed. The work could help us to understand why men and women have different likelihoods of developing some mental-health disorders - and perhaps give insight into treating them, say the researchers."

"For example, women are about twice as likely as men to develop anxiety or depression, and boys are about four times more likely to be diagnosed with autism spectrum disorder than girls. "We are very excited about this study, which to our knowledge is the first one to compare how sex differences in brain networks evolve over the lifespan," says Amy Kuceyeski, a computational neuroimager at Weill Cornell Medicine in Ithaca, New York."

"and say the study does not address differences in gender roles, which are known to be important factors when researching brain mechanisms of health and disease. Human brains do not belong in distinct 'female' and 'male' categories, says Daphna Joel, a neuroscientist at the University of Tel Aviv in Israel, referring to a 2015 study she co-authored, which suggests that each human brain is a mosaic of features, some of which are more common in men, others in women."

Functional MRI data from 1,286 people aged 8–100 reveal that sex differences in functional brain connectivity are minimal in early childhood, increase sharply at puberty, and some continue enlarging through adulthood. Differences concentrate in networks related to the default mode, attention, and limbic systems, potentially linking to sex-skewed prevalence of mental-health conditions such as higher rates of anxiety and depression in women and higher autism diagnoses in boys. Some neuroscientists caution that observed connectivity differences may reflect gender-role and social influences rather than biological sex alone and emphasize that individual brains display mosaics of features rather than binary categories.

Read at Nature