Researchers have found that the brains of men and women are less alike than previously thought, opening up new insights into mental health.
Professor Richard Watts, from the University of Canterbury in New Zealand, led an international study which, through MRI brain scans, uncovered distinct differences in the cellular structure of grey matter regions deep within the brains of the male and female subjects.
Professor Watts said the findings challenged the accepted view that once individual variation in brain size were accounted for there were almost no differences between male and female brains.
He said the contrasts were most obvious in areas that play a major role in mental health, such as the thalamus, hippocampus and amygdala.
“These regions are involved in emotions, memory, learning and attention.
“Previous work has concentrated on sex-related differences in the volumes of brain regions, but by using more advanced imaging technology our team has discovered there are much bigger differences in the cellular structure of these regions, with only a small overlap found between the sexes.”
Professor Watts said the study could shed light on sex differences in the susceptibility of males and females to a range of mental health problems.
“The brain regions and measures that showed the largest differences are also strongly associated with mental health disorders, and this finding may help explain why men and women are at different risk for specific disorders, such as anxiety and mood disorders, autism, and attention-deficit hyperactivity disorder.”
He said this would provide a biological explanation for previous research that had shown females were more likely to suffer from anxiety and mood disorders than males, and autism and antisocial behaviour were more common in males.
Professor Watts said the study was limited because only self-reported “male” or “female” gender was recorded, without consideration of other gender identities.
“Future work will try to uncover to what extent the structural brain differences found relate to biological sex, or to gender,” he said.
