University of Michigan researchers analyzed data of 177 teens, ages 15-17, who had been followed in a larger study since birth. Around 70 percent of the participants were African-American and almost half lived below the poverty line.
Children growing up in poverty are particularly vulnerable to early-life adversity. Those who experience poverty have a much higher risk of being exposed to violence and suffering from a lack of social support, which can have long-term consequences including higher rates of diabetes, cancer, and other diseases.
The research team scanned the brains of the participants with MRI, focusing on the white matter connectivity between several key areas: the amygdala, which is known to play a role in fear and emotion-processing, and specific regions of the prefrontal cortex (PFC).
Previous research by this team had shown that reduced connectivity between the two brain regions is linked to a heightened response to threats in the amygdala.
The scans suggest a link between violence exposure and social deprivation in childhood. Children who had experienced more violence (abuse, exposure to intimate partner violence, or neighborhood violence) and social deprivation (child neglect, lack of neighborhood cohesion, and a lack of maternal support) showed reduced connectivity between the amygdala and the PFC in the teen years.
Neither variable on its own was linked to brain changes. When a child experienced violence but also had social support, the reduced connectivity wasn’t evident. The same was true when a child experienced social deprivation but no violence.
“The implication is that social deprivation may exacerbate the effects of childhood violence exposure when it comes to these white matter connections. Social support, on the other hand, may act as a buffer,” said U-M researcher Dr. Christopher Monk.
The researchers were surprised to find no association between brain changes and mental health issues such as depression or anxiety. However, since mental health problems often manifest during the transition from adolescence into young adulthood, they plan to follow up with the study participants to track mental health and determine whether the link between violence exposure, social deprivation, and brain changes persist.
Source: American College of Neuropsychopharmacology