How does stress and trauma impact adolescent development?

There has been a lot of research that looks into how early life trauma can impact child development and mental health, but less is known about stress and trauma in adolescence. A new study published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging has utilised functional magnetic resonance imaging (fMRI) to investigate effects of acute trauma and stress during adolescence and found that repeated trauma can impact three brain networks, leading to developmental consequences.

Written by Bryony Porteous-Sebouhian

Lead author of the study, Rachel Corr, PhD from the University of North Carolina spoke to Technology Networks and said of the study breaking new ground:

“While negative health outcomes have been associated separately with early life victimization exposure, disrupted adolescent neurodevelopment, and aberrant neural network responses to acute stress, no previous research had examined how these factors are related to each other…This study aimed to put together these pieces of the puzzle.”

What is the brain’s triple network the study aimed to examine?

The three networks the study refers to are:

• the default mode network (DMN)
• the salience network (SN)
• the central executive network (CEN)

The DMN is a set of regions in the brain that is active when humans are being self-reflective, processing internally on their mental state, on thoughts about others, on past memories or looking to the future. The DMN is also deactivated when we are performing cognitive tasks such as solving a math problem.

The SN is responsible for both detecting and filtering various salient stimuli and with the other two networks contributes to communication functioning, social behaviour and self-awareness.

The CEN, also known as the frontoparietal network (FPN), this network is involved in allowing us to sustain attention, perform complex brain solving tasks and communicates with working memory.

Together, these three brain networks, the ‘triple networks’, control our cognition, emotion, perception, and social interaction.

How is the triple brain network impacted by adolescent trauma?

In the study, researchers observed the effects of acute stress on brain activity whilst undergoing and fMRI. They did this by asking 79 children aged 9 to 16 to solve a math problem first at their own pace, and then against a time limit.

The researchers found that there was an increase in functional connectivity between the DMN and CEN while the functional connectivity decreased between the SN and the other two networks. One control that the researchers identified was that those who had experienced ‘polyvictimization’, aka victimisation from parents, peers and other adults, were more likely to experience the reduced functional connectivity between the SN and other networks.

This would suggest, researchers say, that the brains of those adolescents may have adapted to repeated traumas, so that they are less reactive to stressful experiences. Meaning they were less able to complete the timed math solving task successfully.

Editor of the publication the study has been published in, Cameron Carter MD said of the study:

“This study shows how repeated trauma may lead to a maladaptive response to acute stress in important functional brain networks and reveals a potential mechanism by which multiple early life stressors may lead to increased neural vulnerability to stress and the associated liability to future mental health problems.”

This study brings in another new perspective into how trauma can impact the brains and functioning of young people. Importantly it suggests that the vulnerable stages of development are not isolated to between the ages of two and eight as previously thought.

This information is essential in building preventative treatment and therapeutic interventions around things such as Averse Childhood Experiences (ACEs) and proves that young people are vulnerable to the live altering effects of trauma further into adolescence than earlier research suggested.

Researchers acknowledged that there is need for a greater understanding on the neurodevelopmental effects of trauma on the brain, as this will provide researchers with a bigger framework when formulating possible psychiatric outcomes.