© Suzanne Tucker | Shutterstock
Differences in the brains of abused or non-abused adults could be the source of abuse-related mental illness.
Changes in the brain linked to childhood abuse and maltreatment may prime a child for future mental health problems, new research finds.
The study, which compared the brains of teenagers who had been abused as children with those of very similar teens who had not experienced any mistreatment, is one of the first to follow individuals before they are diagnosed with a mental illness. That strengthens the case for a causal link between the damage and the disease, the researchers said.
"Maltreatment makes the subjects vulnerable to major depressive disorder and substance disorder," study researcher Hao Huang, a scientist at the University of Texas Southwestern Medical Center, told LiveScience. "And the damage can be seen even before they develop any disorder."
The abused brain
Numerous studies have linked childhood abuse
to long-lasting changes in the brain. In February, researchers reported in the journal Proceedings of the National Academy of Sciences
that abused, neglected and maltreated kids have smaller hippocampuses
than kids who aren't abused. The hippocampus is involved in memory formation and can shrink as a result of exposure to stress hormones, the researchers told LiveScience.
A more recent study, involving children raised in Romanian orphanages, even found that simple neglect - particularly the lack of a warm and responsive caregiver to bond with - causes permanent changes
in the gray matter and white matter of the brain.
Gray matter is made up of the nerve cell bodies in the brain, while white matter is made of the fat-sheathed projections of these cells, bundled together like telephone wire. White matter makes it possible for brain regions to communicate with one another.
Huang and his colleagues focused their research on the white matter of teenagers' brains. They screened these teens carefully to make sure they were free of medical and psychiatric problems. Nineteen victims of abuse were included, along with 13 teens who were similar to the first group except for never having experienced abuse.
Abuse (also called maltreatment) included physical and sexual abuse
, as well as at least six months of witnessing domestic violence in the home.