Childhood Trauma and the Brain: How Therapy Can Restore Psychological Health After Sexual Abuse

Childhood is a pivotal time in human development, more so than any other phase of life. While physical growth is perhaps the most obvious change during this time, neurological growth is an even more critical—and more complex—process. “The functional capabilities of the mature brain develop throughout life, but the vast majority of critical structural and functional organization takes place in childhood,” writes Dr. Bruce D. Perry, a specialist in childhood trauma. This development is not a static and inevitable biological process. Rather, brain development is deeply dependent on environmental factors, including everything from prenatal care and nutrition to environmental toxins and parenting style. As such, childhood trauma such as sexual abuse can have a profound impact on the brain at particularly critical points of development, interfering with healthy neurological growth. “Simply stated, children reflect the world in which they are raised,” explains Dr. Perry. “If that world is characterized by threat, chaos, unpredictability, fear, and trauma, the brain will reflect that.”

Advances in neurological understanding and brain imaging technologies have revealed that the relationship between childhood trauma and the brain is complex and sexual abuse can affect the developing brain in multiple ways. Both structural and functional changes have been observed in response to traumatic childhood experiences, including:

• Hippocampus: Research has shown that survivors of childhood trauma have reduced volume in the hippocampus. This area of the brain is critical for learning, memory formation, conflict processing, emotional regulation, and and even establishing social bonds, which hippocampal atrophy may disrupt.
• Cerebellum: The cerebellum is central to executive functioning as well as coordination of motor behavior. Childhood trauma can diminish the volume of the cerebellum, potentially compromising cognitive functioning and movement.
• Corpus callosum: Brain imagining studies reveal that childhood trauma such as sexual abuse is associated with decreased volume in the corpus callosum, or white matter. This area of the brain transmits neural messages between the hemispheres of the brain and plays an important role in a variety of neurological functions, such as higher cognitive functions and complex emotional processes “in the context of social interactions.”
• Prefrontal cortex: The prefrontal cortex is responsible for a host of vital functions, including regulation of emotion, behavior, and cognition. People who have experienced childhood trauma may have a smaller prefrontal cortex and reduced volume in critical structures within the prefrontal cortex, including the orbitofrontal cortex, which plays a central role in emotional and social regulation.
• Amygdala: While childhood trauma has not been shown to affect the volume of the amygdala, it is associated with overactivity in this crucial structure, “which helps determine whether a stimulus is threatening and trigger emotion emotional response.”
• Cortisol levels: Cortisol is a stress hormone that modulates your blood pressure and metabolism, reduces inflammation, and assists in memory formation. More importantly, however, cortisol regulates how your body responds to threats and is involved in the fight or flight response mechanism. Maintaining a healthy level of cortisol is essential, as abnormally high or low cortisol levels can have significant physical and emotional effects. Unfortunately, survivors of childhood trauma may have abnormal cortisol levels that may affect cognition, learning, and socialization and elevate risk for externalizing disorders and affective disorders.
• Other neurochemicals: Childhood trauma can alter the dopaminergic, serotonergic, and noradrenergic systems, which are associated with mood, sleep, impulse control, attention, and fine motor control.

If and the degree to which a survivor of childhood sexual abuse will experience these brain changes is highly individual and may depend in part on the severity and duration of abuse.

While the general impact of many of these trauma-induced brain changes can be deduced from the function of particular structures and neurochemicals, those structures and neurochemicals interact in complex ways. For example, as Maia Szalavitz writes in Time, “To cope with overwhelming experiences of distress, the brain can alter patterns of signaling from the pathways involved, which can ultimately leave [multiple] regions underdeveloped from reduced input. The brain of a child who is raped, for example, may react by reducing the connectivity of the regions that were hurt.” As a result, the brain changes associated with childhood sexual abuse are multifaceted and it’s important to explore exactly how these disruptions typically manifest in the lives of childhood sexual abuse survivors.

This kind of childhood trauma tends to find expression in particular ways that come to define post-traumatic responses:

• Persistent fear response and hyperarousal: Fear responses are a normal and healthy part of life, helping us identify dangers and take action to protect ourselves in the face of threat. However, childhood trauma, particularly repeated trauma, can alter the natural and logical fear response. According to the U.S. Department of Health and Human Services, “Chronic activation of the neuronal pathways involved in the fear response can create permanent memories that shape the child’s perception of and response to the environment.” In other words, while a fear response may be rational and even helpful at the time of the traumatic event, repeated activation of that response can compromise survivors’ ability to “differentiate between danger and safety” and leave you in a constant state of fear. This persistent fear response can cause you to enter a state of hyperarousal and hypervigilance, as your are constantly on the lookout for potential threats. Hyperarousal and hypervigilance may, in turn, cause you to misinterpret environmental and social cues, as you see the world through the distorted lens of trauma. Additionally, you may struggle with concentration and learning, as your brain is occupied by the conscious and unconscious project of watchfulness.
• Emergence of mental health disorders: Much of the relationship between childhood trauma and brain changes involve regions, functions, and neurochemicals, associated with regulation of emotions and stress. Disruption of these regions and functions, both individually and in combination, may lead to the development of mood and anxiety disorders, including depression, posttraumatic stress disorder (PTSD), and social anxiety disorder. Additionally, childhood sexual abuse has been associated with the development of certain personality disorders, particularly borderline personality disorder, which may arise in part due to the neurological conditions created by early trauma.
• Diminished response to positive feedback: Childhood trauma has been found to interfere with reward processing and reduce survivors’ response to positive stimuli, reducing the ability to experience rewards and potentially interfering with motivation.
• Diminished executive functioning: Executive functioning involves a variety of activities, including inhibitory control, working memory, and cognitive flexibility. The brain changes caused by childhood sexual abuse can interfere with all facets of executive functioning, diminishing academic and professional performance, compromising social aptitude, disrupting everyday activities, and increasing risk-taking. In severe cases, survivors may experience intellectual impairment.
• Social impairment: The experience of childhood sexual abuse can fundamentally alter the way you regard other people and your ability to form healthy relationships. This may be particularly true if your abuse was a caregiver and the trauma disrupted a primary attachment bond. While this is understandable from a psychological standpoint, social interactions may also become more complicated and difficult due to the brain changes brought on by trauma. Persistent stress response combined with diminished ability to read social cues and potential disruptions of empathy can interfere with your ability to engage in positive social interactions both in the moment and over the long-term. For example, research shows that survivors of childhood trauma are more likely to exhibit aggressive behaviors even in non-threatening situations, which experts believe to be the result of not only interactions between major brain structures, but enhanced gene expression for monoamine oxidase A (MAOA) . MAOA is referred to as “the warrior gene” due to its association with aggressive behavioral traits, particularly in social contexts. The ability of trauma to alter gene expression serves as a prime example of how deep and complex the effects of such trauma can be.
• Altered Sensory Experiences: Many survivors of sexual abuse report experiencing a variety of somatic sensory disruptions, particularly when it comes to sexual organs and experiences. In recent years, researchers have begun to connect these disruptions to specific brain changes caused by childhood sexual trauma. In particular, trauma-induced changes in the somatosensory cortex of women have been associated with altered physical sensations and perceptions, particularly in the genital area. This may explain the reduced sexual desire, decreased sexual sensation, lower pain threshold, and even chronic genital pain some women report after experiencing childhood sexual abuse. If the abuse involved other parts of the body, the areas of the somatosensory cortex associated with those body parts also appear to be changed.

How exactly each person responds to the trauma of childhood sexual abuse is, of course, unique and may be influenced by a variety of factors, including resilience, social support, and the nature of the abuse. However, the above responses reflect common patterns often seen in survivors, the underpinnings of which become more clear as we gain greater insight into the relationship between childhood abuse and brain changes.