Effects of Maltreatment on Brain Development

There have been a few requests lately for more information on how trauma affects a child’s brain and the child’s ability to form attachments and learn. The following is a summary of an article, Understanding the Effects of Maltreatment on Brain Development, published by the US Department of Health and Human Services’ Child Welfare Information Gateway www.childwelfare.gov/pubs/issue_briefs/brain_development

Thanks to the relatively recently developments in the study of brain development including functional magnetic resonance imaging, there is now evidence to show that brain function is altered significantly. “…genetics predisposes us to develop in certain ways. But our experiences, including our interaction with other people have a significant impact on how our predispositions are expressed. In fact, research now shows that many capacities thought to be fixed at birth are actually dependent on a sequence of experiences combine with heredity. (Shonkoff and Phillips, 2000).”

An infant is born with almost all of the brain neurons that it will ever have. As the brain developed in the fetus these neurons began to specialize, developing specific tasks for the lifespan of the person. This development continues after birth and on into adulthood. The first regions to develop are those concerned with bodily functions and maintaining life. “But the majority of brain growth and development takes place after birth, especially higher brain regions involved in regulating emotions, language and abstract thought. Each region manages its assigned functions through complex processes that involved chemical messengers (Perry, 2000a).”

Plasticity is the term used to describe the brain’s ability to change in response to stimulation. This is dependent on the stage of development and the specific region of the brain that is affected. The part of the brain that is “wired” to respond to the human voice or facial expression anticipates the exposure and when this does not happen, the brain will discard these pathways. The brain will discard pathways that are not being used and develop other pathways that are needed for survival.

There are sensitive periods for the development of certain capabilities. “For example, infants have the genetic predisposition to form strong attachments to their caregivers. But if a child’s caregivers are unresponsive or threatening, and the attachment process is disrupted, the child’s ability to form any healthy relationships during his or her life may be impaired )Perry, 2001a).

Babies are born with implicit memory which means they have a perception of the environment that can be recalled in unconscious ways (responding to the sound of mother’s voice). Explicit memory is tied to language development and provides children around the age of 2 with the ability to talk about themselves in the past or future or in different places or circumstances. However, children who have been abused or suffered other trauma may not be able to retain the explicit memories that they need to be able to tell about their trauma. Instead, they will experience the implicit memories such as bodily or emotional sensations that manifest as nightmares, flashbacks or other uncontrollable reactions.

Children can learn to tolerate moderate stress and greater amount of stress can be tolerated if he/she has a positive relationship with an adult caregiver. However, without this positive interaction in significant amounts at critical periods, the brain can be altered by the toxic stress. Specific effects depend on the age of the child, whether the trauma was one-time or chronic, the identity of the abuser, and whether there is a dependable nurturing adults present, the type and severity of the abuse, the intervention, and how long the maltreatment lasted.

“Altered brain development in children who have been maltreated may be the result of their brains adapting to their negative environment. If a child lives in a threatening, chaotic world, the child’s brain may be hyperalert for danger because survival may depend on it. But if this environment persists, and the child’s brain is focused on developing and strengthening its strategies for survival, other strategies may not develop as fully. The result may be a child who has difficulty functioning with a world of kindness, nurturing, and stimulation.”

Children who are exposed to long term and severe abuse, either emotional or physical/sexual, will develop responses such as a persistent fear response, hyperarousal, dissociation and disrupted attachment (inability to form relationships). The neural pathways have formed these responses as a means of surviving the impact of the trauma. However, these responses also result in increased susceptibility to stress, excessive help-seeking and dependency or excessive social isolation, and the inability to regulate emotions. The effects are cumulative and can lead to life long difficulties in interpersonal relationships.

“Some of the specific long-term effects of abuse and neglect on the developing brain can include (Teicher, 2000): diminished growth in the left hemisphere, which may increase the risk for depression; irritability in the limbic system, setting the stage for the emergence of panic disorder or posttraumatic stress disorder; smaller growth in the hippocampus and limbic abnormalities (areas of emotions and memories in the brain), which can increase the risk for dissociative disorders and memory impairments; impairment in the connection between the two brain hemispheres, which has been linked to symptoms of attention-deficit/hyperactivity disorder.

The U.S. Department of Health and Human Services Children’s Bureau (2009) encourages professionals to promote five “protective factors” that can strengthen families, prevent abuse and neglect, and promote healthy brain development: nurturing and attachment, knowledge of parenting and of children and youth development, parental resilience, social connections, and concrete support for parents.

For additional information go to www.nhcadsv.org to access the recent publication, The Mental Health Needs of Children Exposed to Violence in their Homes.