Child abuse can affect brain functions later life: Study

By Dr. Ananya Mandal, MDDec 6 2011

According to a new research from Yale University, teenagers who were abused as young children show changes in their brains that put them at risk for behavioral problems in adulthood.

The study looked at brain scans of adolescents who suffered physical abuse and neglect showed differences in the part that controls executive function - mental processes such as planning, organizing and focusing on details. The study appeared in the Archives of Pediatric and Adolescent Medicine. Changes were also seen in brain areas that regulate emotions and impulses, the study said.

The study authors write that nearly 3.7 million U.S. children are assessed for child abuse or neglect each year, but the number may be higher as many cases don’t come to the attention of professionals. The research, which evaluated teenagers who hadn’t been diagnosed with a psychiatric disorder, suggests abuse or neglect victims be monitored to reduce the risk of disorders like depression and addiction, researchers said.

Philip Fisher, a professor of psychiatry at the University of Oregon and a senior scientist at the Oregon Social Learning Center in Eugene, who wrote an accompanying editorial in the journal said, “What these findings show is that experiences that people have early in life can really subsequently and fundamentally alter the way their brain develops…These kids, in spite of the fact that they didn’t have actual disorders, have the potential to be very vulnerable for problems over the course of their development.” Fisher added that human brains continue to develop through early adulthood, particularly the area that regulates emotions and executive function.

For the study the researchers included 42 children aged 12 to 17 who didn’t have a psychiatric diagnosis. The researchers used questionnaires to determine if the children suffered from physical abuse, physical neglect, emotional abuse, emotional neglect and sexual abuse. They then took images of their brains using MRI.

Results from scans revealed that girls were more likely to have differences in brain areas related to emotional processing, making them more vulnerable to mood disorders like depression, while boys had changes to areas for impulse control, which could make them more vulnerable to drug and alcohol addictions, said study author Hilary Blumberg, an associate professor of psychiatry and diagnostic radiology in the Child Study Center at Yale School of Medicine in New Haven, Connecticut.

Previous studies that scanned the brains of soldiers exposed to violent combat situations showed the same pattern of heightened activity in these two brain areas - the anterior insula and the amygdala - which experts say are associated with detecting potential threats. This suggests that both maltreated children and soldiers may have adapted to become “hyper-aware” of danger in their environment, the researchers said.

“Enhanced reactivity to a...threat cue such as anger may represent an adaptive response for these children in the short term, helping keep them out of danger,” said Eamon McCrory of Britain's University College London, who led the study. But he added that such responses may also be underlying neurobiological risk factor which increases the children's susceptibility to later mental illness like depression. McCrory said still relatively little is known about how such early adversity “gets under the skin and increases a child's later vulnerability, even into adulthood.”

Additionally those who suffered from abuse as well as neglect also showed brain changes. The study didn’t show distinct patterns in the brains of children who were sexually abused, although Blumberg said that may be because the number of children who were sexually abused was small. “It was very important to see the findings with regard to neglect,” Blumberg said. “That was an area that had been little studied.”

“We are only now beginning to understand how child abuse influences functioning of the brain's emotional systems,” McCrory said. “This research...provides our first clues as to how regions in the child's brain may adapt to early experiences of abuse.” As a next step the researchers are following up the teenagers to see if they develop behavior problems like depression or substance abuse.