Tracing the Effects of Childhood Trauma

April 30, 2020

What happens when the maternal-child relationship goes awry?  Bridget Callaghan thought about this question even as a child and is devoting her professional career to finding answers.

“We’re trying to understand how experiences, especially of adversity, influence the development of the brain and body, and how they interact to produce physical and mental health and disease outcomes,” said Callaghan, assistant professor of psychology and director of the Brain and Body Lab (BABLab) at UCLA.

Bridget Callaghan, PhD

A native Australian, Callaghan is a recipient of a 2020 Federation of Associations in Behavioral & Brain Sciences (FABBS) Early Career Impact Award.  She was nominated by the International Society for Developmental Psychobiology. 

At UCLA, Callaghan is recruiting 150 children ages 6 through 18, half living with their birth parents and the other half with adoptive parents after experiencing the foster care system.  She has 30 recruited so far and is using a memory game and collecting biological samples to garner information on how their brains and bodies—specifically their gastrointestinal tracts—may have been altered as a result of challenges in the early caregiving environment.

Participants look for toys and candy hidden inside a haunted-looking house on a computer screen.  They perform the same task two weeks later but with additional items and this time lying inside an MRI scanner affixed with a mirror reflecting the computer monitor. 

The imaging component helps Callaghan determine how adversity impacts the development of the hippocampus, which controls memory and emotion. She also takes stool samples to assess gastrointestinal bacteria and health. 

Among other goals, she wants to know how the microbiome, hippocampus and early life adversity converge to influence mental illness, specifically anxiety.

“We don’t have a good understanding of how adversity influences brain development, and we definitely don’t have good idea of how it influences the gastrointestinal tract and microbiome,” she said. “Animal studies tell us these things should be related, so it is important to look at it in humans.”

Callaghan’s work is an extension of studies she performed while earning her post-doc at Columbia University in 2019.  There, she recruited children who had been living in institutions and orphanages before adoption here in the United States. Those children also performed a memory game, similar to the one she uses now except the house was not scary looking and the children were scanned while they were learning the task. 

Among other findings, children in the control group “had a nice developmental gradient in the way the hippocampus responds to learning,” she said.  Children exposed to adversity had higher levels of gastrointestinal distress.

Callaghan said she hopes her research might lead to better treatments for people who have survived childhood trauma. And she hopes to get at an overarching question in psychology: how does early trauma enact such upheaval when most of us can’t even remember our toddler years.

“The experience could get under your skin in other ways,” she suggested, “such as through gastrointestinal function, emotions and behavior.”