From The Quarterly, Fall 2014

Over the last two decades, researchers have learned that severe stress experienced early in life can change the brain in ways that affect behavior well into adulthood. New research led by Deanna M. Barch, Ph.D., of Washington University in St. Louis, a 2013 NARSAD Distinguished Investigator Grantee, has made progress in identifying these brain changes in young children. Her colleagues in this work include Joan L. Luby, M.D. and Kelley N. Botteron, M.D., who have received multiple grants from the Foundation.

The team reported their findings in the July 2014 issue of the Journal of the American Academy of Child & Adolescent Psychiatry. The results suggest that hyperactivity in the limbic areas of the brain—those involved in emotions and behavior—may be a biomarker (or biological predictor) that doctors can use to identify children exposed to stress and trauma that are likely to go on to develop stress-related disorders.

It is more difficult to study young children than adults when it comes to mental health. Abuse of a child or a child’s caretaker is likely hidden and many children cannot articulate their symptoms. For these reasons, an objective biomarker of stress and trauma would be of immense value.

Dr. Barch’s team selected a group of children aged three to five years old who were given initial psychiatric evaluations. Some of the children were deemed to be “healthy controls,” others had been subjected to stress or trauma, and some had already developed disorders such as depression. As these children grew to ages seven to 12 they were given functional magnetic resonance imaging (fMRI) brain scans to measure the level of activity in the brain while they responded to pictures of faces. The faces expressed the gamut of emotions from fearful, sad, or neutral to happy.

Most important, perhaps, was the observation that children who had experienced life stress or trauma showed higher levels of limbic brain activity than did healthy children. Unexpectedly, the specific areas of the brain that were overactive differed, depending on whether the child had experienced stress or trauma.

In all of the children who had experienced stress, an important part of the limbic system, the amygdala*, was hyperactive when pictures were shown of faces displaying emotion. Activity was normal when the face lacked emotion. Children who had experienced trauma showed over-activity when shown sad faces, but not other “emotional” faces. Children diagnosed with depression and those with other psychiatric illnesses showed abnormal activity in different parts of the limbic areas.

Their findings, the authors state, “suggest that limbic hyperactivity may be a biomarker of early life stress and trauma in children and may have implications in the risk trajectory for depression and other stress-related disorders.” This new work may be providing a pathway for early diagnosis and intervention in stress-related psychiatric illness.