Study: Child abuse damages brain

Dr. Hao Huang’s study found adolescents who were abused or witnessed home violence developed changes in their brains’ white matter.

By Jan Jarvis

Being abused as a child can cause structural changes in the brain that may set the stage for depression and substance abuse in adulthood, researchers at UT Southwestern Medical Center report.

In a study published in Neuropsychopharmacology in August, researchers compared the brains of adolescents who had been abused or witnessed violence in their homes with those who had not. They found changes occurred only in the brains of those who had been abused or witnessed violence.

The study results, despite the small sample size, might help identify high-risk adolescents in need of preventive intervention, said Dr. Hao Huang, Assistant Professor of Radiology in the Advanced Imaging Research Center. The findings shine light on the developing brain and how domestic violence or emotional, physical, or sexual abuse affects it, said Dr. Huang, lead author of the study.

“This could be a way to intervene or prevent a mental disorder before symptoms develop,” said Dr. Huang, who would like to do a larger trial as a follow-up. “That is what we hope.”

The structural damage caused by abuse in early childhood can be reversed, but it is not a fast process and may take months to years, he said.

“With no intervention, it is very likely that a child who is maltreated will develop major depression or substance abuse disorder,” Dr. Huang said.

For this study, researchers used a type of magnetic resonance imaging called diffusion tensor imaging to scan the brains of 32 teenagers, 19 of whom had been abused or witnessed violence in their homes. Five of the 19 developed depression later compared to one in the control group. Four of the 19 became substance abusers, but only one of the teens that had not been maltreated did. All participants were scanned at the study’s outset and followed at six-month intervals for up to five years to obtain information on development of mood and substance abuse disorders. 

The imaging technique that was developed in Dr. Huang’s lab to scan the teens’ brains made it possible to use a noninvasive approach to assess the integrity of white-matter tracts, Dr. Huang said. 

The human brain is composed of two parts: gray and white matter. The white matter tracts work like wires connecting different gray-matter regions of the brain and transmit signals among them, Dr. Huang explained.

“It’s how the different regions talk to each other,” he said.

Most noteworthy, changes in the white matter of the brain could be seen even before the teens were diagnosed with depression, lending further support for the link between childhood abuse and mental illness.

“We found damage before the development of a disorder,” Dr. Huang said. “It is structural evidence. It’s not based on how someone feels.”

Not everyone who experiences abuse and has damage to their white brain matter will develop depression, Dr. Huang said. There will be some who develop into normal adults. But the research could lead to earlier intervention for children at risk for depression, a condition that affects more than 20 million adults.

“The earlier, the better for these kids,” Dr. Huang said.