Childhood stress may cause delay in brain development
By Margaret Rogers
Children who experience acute stress in their early years may, as a result, have altered growth in a specific part of the brain and the 
abilities associated with it, according to researchers.
The research was conducted by University of Wisconsin-Madison (UW-Madison). Jamie Hanson, a psychology graduate student from UW-Madison said ‘There has been a lot of work in animals linking both acute and chronic stress to changes in a part of the brain called the prefrontal cortex, which is involved in complex cognitive abilities, like holding on to important information for quick recall and use. We have now found similar associations in humans, and found that more exposure to stress is related to more issues with certain kinds of cognitive processes.’
The researchers used tests to assess ‘spatial working memory’ in children who had experienced lasting stressful events in their lives. They found that they achieved lower scores in these tests compared to children who had not been exposed to stress. The stressed children also had more trouble when navigating tests of short-term memory, according to the researchers.
By using brain scans, the researchers could see that the anterior cingulate, a part of the prefrontal cortex that is thought to play key roles in spatial memory, takes up less space in children with greater exposure to acute stress.
Hanson said ‘These are subtle differences, but differences related to important cognitive abilities. We’re not trying to argue that stress permanently scars your brain. We don’t know if and how it is that stress affects the brain.’
He added ‘We only have a snapshot – one MRI scan of each subject – and at this point we don’t understand whether this is just a delay in development or a lasting difference. It could be that, because the brain is very plastic, very able to change, that children who have experienced a great deal of stress catch up in these areas.’
The child participants in this study were aged between 9 and 14. The researchers assessed stress levels using interviews with both the children and their parents. They collected extensive information on stressful events which ranged from slight to severe.
Hanson said ‘Instead of focusing in on one specific type of stress, we tried to look at a range of stressors. We wanted to know as much as we could, and then use all this information to later get an idea of how challenging and chronic and intense each experience was for the child.’
A full account of this study is published in the Journal of Neuroscience
