Traumatic stress found to affect brains of boys, girls differently

A new study suggests that a brain region that integrates emotions and actions appears to undergo accelerated maturation in adolescent girls with post-traumatic stress disorder (PTSD), but not in boys with the condition.

Among youth with post-traumatic stress disorder, the brain-scanning study by researchers at Stanford University School of Medicine found structural differences between the sexes in one part of the insula, a brain region that detects cues from the body and processes emotions and empathy.

"The insula appears to play a key role in the development of PTSD," said Victor Carrion, professor of psychiatry and behavioral sciences at Stanford and senior author of the study published online in Depression and Anxiety. "The difference we saw between the brains of boys and girls who have experienced psychological trauma is important because it may help explain differences in trauma symptoms between sexes."

Among young people who are exposed to traumatic stress, some develop PTSD while others do not. People with PTSD may experience flashbacks of traumatic events; may avoid places, people and things that remind them of the trauma; and may suffer a variety of other problems, including social withdrawal and difficulty sleeping or concentrating.

The Stanford research team conducted MRI scans of the brains of 59 study participants ages 9 to 17. Thirty of them, 14 girls and 16 boys, had trauma symptoms; and 29 others, the control group of 15 girls and 14 boys, did not. The participants had similar ages and IQs. Of the traumatized participants, five had experienced one episode of trauma, while the remaining 25 had experienced two or more episodes or had been exposed to chronic trauma.

The researchers saw no differences in brain structure between boys and girls in the control group. However, among the traumatized boys and girls, they saw differences in a portion of the insula called the anterior circular sulcus.

This brain region had larger volume and surface area in traumatized boys than in boys in the control group. In addition, the region's volume and surface area were smaller in girls with trauma than among girls in the control group.

The insula normally changes during childhood and adolescence, with smaller insula volume typically seen as children and teenagers grow older.

Thus, the findings imply that traumatic stress could contribute to accelerated cortical aging of the insula in girls who develop PTSD, said Megan Klabunde, the study's lead author and an instructor of psychiatry and behavioral sciences. "There are some studies suggesting that high levels of stress could contribute to early puberty in girls."

"By better understanding sex differences in a region of the brain involved in emotion processing," the researchers wrote in the study, "clinicians and scientists may be able to develop sex-specific trauma and emotion dysregulation treatments." Endit