It is no secret that experiencing childhood trauma can have many negative effects on an individual’s life both in childhood and adulthood. Trauma can include events such as physical or sexual abuse, surviving a serious car accident, witnessing a violent event, and more. As trauma is defined in the dictionary as a deeply distressing or disturbing experience, it is no surprise that a disturbing event during childhood can have negative effects throughout an individual’s lifetime. However, this paper will dive deeper into the behavioral, cognitive, emotional, and neurobiological implications of childhood trauma. Specifically, it will discuss the impact childhood trauma has on the developing brain with regards to neurobiology and subsequent functioning. In addition, it will explore the behavioral manifestation of trauma in children through reexperiencing, avoidance, and more. Lastly, it will demonstrate the correlation between trauma and depression and PTSD in adulthood.
During the first few years of a child’s life and even into adolescence, children are more likely to spend a significant amount of time with family and/or caregivers. That being said, if a child is exposed to violence, abuse, or neglect during these early years in a primary setting such as the home, this may stimulate a constant fear within the child including fear that the event may happen again (Cross, Fani, Powers, & Bradley, 2017). Because these events have such a strong impact on the child’s emotions and happen at such a crucial stage of development, it is likely to have a profound effect on neurobiological development.
It is extremely important to understand why the brains of children are so vulnerable to trauma as opposed to an adult. The rate of development during early childhood is “unprecedented compared to any other period in the lifespan” (Young, Kenardy, & Cobham, 2011). Thus, the timing of the trauma is incredibly important to consider. As explained by Cross et al. (2017), when children develop, they go through “sensitive periods” where they are more vulnerable to experiences and neural inputs. These sensitive periods are marked by increased plasticity, or flexibility, during which experience is highly influential on synaptic growth and organization of neural circuits. Therefore, exposure to trauma during these sensitive periods can be highly influential when it comes to neurobiological development. In addition, these sensitive periods may be prolonged if the environmental input is inconsistent or unexpected (Cross et al., 2017). Because childhood trauma is often characterized as being unexpected, it may prolong these sensitive periods, leading to increased vulnerability of the developing brain.
In addition, childhood trauma can have significant impacts on the structure and function of the hippocampus, prefrontal cortex, and amygdala. It is important to recognize that these three regions of the brain are all connected and function together as well as individually. Research demonstrated by Cross et al. discusses that these brain regions mature at an unequal pace but are still highly connected when it comes to development. Because brains are structurally and functionally connected, the prefrontal cortex for example could facilitate or inhibit activity in another region such as the amygdala. This is a great demonstration of how every region of the brain is connected in some way. Thus, chronic stress resulting from childhood trauma reduces connectivity within the network of the brain which can have lasting negative effects. Childhood trauma can impact these regions in ways that can “diminish capacity for consciously managing recollections of the events and moderating fear responses” (Cross et al., 2017). In other words, trauma can impact how the brain interprets and copes with the fear trauma creates.
While trauma can have a significant impact on the structure of the brain, it can also largely influence how the brain functions and processes information. The brain is composed of over 100 billion neurons, all of which are designed to change and adapt in response to external inputs (Perry, Pollard, Blakley, Baker, & Vigilante, 1995). That being said, the brain functions in a use-dependent fashion. In other words, the brain shapes and adapts based on the frequency of certain events. A few good examples of use-dependent storage are learning and cognitive memory. As Perry et al. describes, “the more a neural network is activated, the more there will be use-dependent internalization of new information.” Thus, when a child experiences trauma more than once in their childhood, this manifests in a use-dependent fashion, adapting to this experience and storing this representation for later use.
One of the many functions that is impacted by childhood trauma is executive function in the prefrontal cortex. As mentioned before, research on childhood trauma has shown that there is a significant impact on the structure and functioning of the prefrontal cortex. Executive functions in this region include working memory, cognitive flexibility, inhibitory control, and the ability to form abstract concepts (Cross et al., 2017). Working memory is the part of short-term memory involved in rapid perceptual processing. Cognitive flexibility and inhibitory control include inhibiting previously learned responses to learn a new response and inhibiting overlearned or automatic responses. These functions of the prefrontal cortex are all extremely important in learning to cope and adjust to different experiences. Research has shown that exposure to trauma leads to significant impairments in executive function processes (Cross et al., 2017).
Another function of the brain impacted by trauma is emotional regulation. As defined by Cross et al., this function consists of strategies used to manage behavioral, cognitive, and physiological responses to emotion and includes many components such as understanding, awareness, and acceptance of experiences. Importantly, developmental research has demonstrated that childhood trauma has a significant impact on children’s emotional awareness, understanding, and regulation. This is largely due to lack of appropriate role models and dependence on executive function (Cross et al., 2017). Specifically, because childhood trauma often involves abuse from a primary caregiver or violence within the home, this often results in children lacking good role models to help demonstrate proper emotional regulation. In addition, emotional regulation may be lacking due to its slight dependence on executive function. For example, executive function uses working memory to fend off excessive bad thoughts or stimuli and helps to adapt to new coping methods when old strategies are no longer useful (Cross et al., 2017). It is clear that emotional regulation relies partially on executive function. That being said, when executive function is impaired from childhood trauma, emotional regulation is also negatively affected. This is another great example of how regions and functions in the brain are connected.
While trauma has many effects on the brain itself, it also has subsequent behavioral ramifications. Childhood trauma often manifests through reexperiencing, avoidance, and dissociation. Reexperiencing often includes participating in post-traumatic play in which they repeat the themes from the trauma over and over again. This often results in an increase in distressing nightmares as well as an increase in intense emotional and physical reactions when exposed to reminders of the trauma (Young et al., 2011). Avoidance includes children secluding themselves from things that may remind them of the trauma including exposure to conversations, people, objects, situations, and places. This can be detrimental to social development because these children often are not able to interact with others in a healthy way. This makes it difficult to create healthy relationships with peers. Lastly, these two manifestations can lead to dissociation, which is characterized as an episode where the child appears frozen and unresponsive to stimuli. On the opposite spectrum, trauma can manifest through hyperarousal, which results in disturbed sleep, temper tantrums, and more (Young et al., 2011). Regardless of how the trauma manifests, each behavior can have negative developmental implications that result in inappropriate coping methods, impairment in social development, and decrease in overall mental health.
As an adult, childhood trauma can have a significant impact on whether or not someone develops depression. Although it is difficult to establish a cause/effect relationship between the two, multiple instances of research have found that those who are exposed to childhood trauma are more likely to experience depressive symptoms (Colman et al., 2013). These researchers conducted a study in which 3,930 participants were asked if they had experienced a list of childhood traumatic events, if they had undergone recent a constant life stressor, and if they were depressed. Results demonstrated that individuals who had undergone some sort of childhood trauma were more likely to be depressed in the event of a life stressor such as losing a job or household financial problems (Colman et al., 2013). This survey was conducted with these individuals over a period of 15 years, which demonstrated that the experience of childhood trauma stuck with them throughout the years and had a lasting impact in adulthood.
Interestingly, another group of researchers conducted a survey of 349 chronically depressed patients to determine what types of childhood trauma were linked to more depressive symptoms. As a self-report measure, participants were asked about their histories, and severity of depression was measured by diagnoses made by trained professionals. Results found that about 76% of the participants had experienced significant instances of childhood trauma (Negele, Kaufhold, Kallenbach, & Leuzinger-Bohleber, 2015). In addition, 37% of the patients were exposed to multiple instances of trauma. It is important to note that the individuals who experienced multiple childhood traumas had more severe depressive symptoms than those with only one trauma (Negele et al., 2015). This makes sense considering the fact that repetition within the brain at a young age creates a more solidified mental representation, which leads to more lasting negative effects. Lastly, Negele et al.’s study found that individuals who experienced emotional and sexual abuse in childhood were likely to exhibit more severe depressive symptoms than other forms of childhood trauma. These are all important implications of how childhood trauma manifests as depression in adulthood.
It is clear to see that childhood trauma manifests in many different ways throughout childhood and adulthood. Specifically, it is important to understand the many effects trauma has on the structure and function of the brain has as well as resulting behavioral manifestations. These resulting impacts can have many impacts on social, cognitive, emotional, and neurobiological development that are all connected in some way or another. Lastly, it is imperative to understand the likelihood of depression developing in adults who undergo trauma. It is clear through these many impacts that childhood trauma has many lifelong implications on the individual.