Traumatic Stress May Alter Boys' and Girls' Brains Differently

A new brain-scanning study has found that traumatic stress affects the brains of adolescent boys and girls differently.

Among youth with post-traumatic stress disorder (PTSD), the study 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 helps to integrate one’s feelings, actions and several other brain functions, said researchers from the Stanford University School of Medicine.

“The insula appears to play a key role in the development of PTSD,” said the study’s senior author, Victor Carrion, M.D., a professor of psychiatry and behavioral sciences at Stanford. “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.”

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.

Prior research has shown that girls who experienced trauma are more likely to develop PTSD than boys who experience trauma, but scientists have been unable to determine why.

For the new study, researchers conducted MRI scans of the brains of 59 children between the ages of nine and 17.  According to the researchers, 30 of the study participants — 14 girls and 16 boys — had trauma symptoms, while the remaining 29 — a control group of 15 girls and 14 boys — did not.

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 report they 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.

“It is important that people who work with traumatized youth consider the sex differences,” said Megan Klabunde, Ph.D., the study’s lead author and an instructor of psychiatry and behavioral sciences. “Our findings suggest it is possible that boys and girls could exhibit different trauma symptoms and that they might benefit from different approaches to treatment.”

The insula normally changes during childhood and adolescence, with smaller insula volume typically seen as children and teenagers grow older. The findings imply that traumatic stress could contribute to accelerated cortical aging of the insula in girls who develop PTSD, according to Klabunde.

“There are some studies suggesting that high levels of stress could contribute to early puberty in girls,” she said.

The researchers also noted that their work may help scientists understand how experiencing trauma could play into differences between the sexes in regulating emotions.

“By better understanding sex differences in a region of the brain involved in emotion processing, clinicians and scientists may be able to develop sex-specific trauma and emotion dysregulation treatments,” the researchers said in the study, which was published in Depression and Anxiety.

To better understand the findings, the researchers said what’s needed next are longitudinal studies following traumatized young people of both sexes over time.

Source: Stanford University Medical Center