17, No. 2
How Trauma Affects Child Brain Development
The sheer volume of research on trauma, brain development, and outcomes for children can be daunting. Fortunately, understanding and applying key concepts to child welfare practice doesn’t have to be complicated.
Trauma and the Brain
Neurons are the building blocks of the brain. During development, neurons create networks that link to create systems. These systems are how the brain regulates all functions. Brain functions are organized from the most simple to the most complex. The development of these functions is sequential, meaning prior events impact future development.
A key fact that child welfare professionals, judges, and others who work with child welfare-involved families should know is that there are critical developmental times when neural pathways are being formed that can be significantly altered by traumatic events (Perry, 1995, 2009).
When experiences are traumatic, the pathways getting the most use are those in response to the trauma; this reduces the formation of other pathways needed for adaptive behavior. Trauma in early childhood can result in disrupted attachment, cognitive delays, and impaired emotional regulation. Also, the overdevelopment of certain pathways and the underdevelopment of others can lead to impairment later in life (Perry, 1995).
By age three, the brain is almost 80% of its adult size; by age five it is 90% (zerotothree.org). Although this creates a sense of urgency regarding intervention, it is also important to know that the brain has the most plasticity in infancy and early childhood, meaning there is the most opportunity for change. This is both the reason that prolonged trauma in early childhood can be so devastating, but also a window of opportunity for interventions that can alter the brain in positive ways (CWIG, 2011).
Children and Teens
The impact of trauma at this age also depends on the onset. If trauma continues into the school-age years from early childhood, the impact is greater on overall functioning. There is some evidence that trauma that begins during the school-age years will have a different impact than trauma that begins in early childhood. Specifically, school-age onset seems to result in more externalizing behaviors (acting out) whereas early childhood onset results in more internalizing behaviors (withdrawal, depression, self-blame) (Manly, 2001; Kaplow, 2007).
In adolescence the brain goes through another period of accelerated development. The pruning of unused pathways increases, similar to early childhood. This process makes the brain more efficient, especially the part of the brain that supports attention, concentration, reasoning, and advanced thinking. Trauma during adolescence disrupts both the development of this part of the brain and the strengthening of the systems that allow this part of the brain to effectively communicate with other systems. This can lead to increased risk taking, impulsivity, substance abuse, and criminal activity (NCTSN, 2008; Chamberlin, 2009; Wilson, 2011; CWIG, 2009).
What You Can Do