The Effects of Complex Trauma on Brain Development

Introduction

Exposure to complex trauma in early childhood leads to structural and functional brain changes. Structural changes alter the volume or size of specific brain regions. Proven structural changes include enlargement of the amygdala, the alarm center of the brain, and shrinkage of the hippocampus, a brain area critical to remembering the story of what happened during a traumatic experience. Functional changes alter activity of certain brain regions. These include overproduction of stress hormones in childhood that can wear down the immune system and lead to depletion by adulthood of hormones necessary tolerate and recover from stressful situations encountered in daily life.

Many such abnormalities identified through neuroimaging that have previously been attributed to psychiatric illness have been scientifically proven to be the result of prior childhood maltreatment.

Timing and Type of Trauma Matters

Implicated brain regions and interconnecting pathways have been found to have sensitive periods in childhood when they are most vulnerable to the effects of trauma exposure.

In addition, exposure to specific forms of complex trauma in childhood — including neglect, emotional/verbal abuse, sexual abuse, and witnessing domestic/family violence — has been shown to have distinct effects on specific brain regions.

Complex Trauma Changes the Brain: For Worse or Better?

The effects on brain development caused by exposure to complex trauma in childhood have been associated with:

• psychopathology
• maladaptive coping, and
• heightened behavioral and health risk trajectories.

The Good News

Nevertheless, there is an interesting wrinkle to this story. Leading neuroscientists, foremost among them Dr. Martin Teicher at Harvard University, have demonstrated, on the basis of considerable research, that many of these seemingly negative effects are best understood as survival-based alterations that are actually highly adaptive.

In other words, while these changes in the brain are associated with a number of problems, they came about to help people survive in the face of ongoing trauma as well as to anticipate and prepare for living in a world that continues to be dangerous and hostile.

Are Trauma-Related Brain Changes Permanent, or Can They be Reversed?

Previously presumed to represent irreversible damage, neuroscientific research has begun to suggest that some structural changes to the brain caused by exposure to complex trauma are reversible.

Individual studies have demonstrated the capacity to reverse negative alterations in certain important brain structures. For example, corrective repair to reductions in volume or size have been observed for these important brain structures:

• White matter: the connective bundles that relay and communication between different brain regions
• Hippocampus: an important part of the limbic system involved in consolidation of memories.

Then there is the fascinating series of studies on telomeres, the protective “caps” at the ends of each chromosome that are necessary for DNA replication which in turn is essential to for all living things, including humans, to keep living.

Accelerated erosion of telomeres has been linked to exposure to complex childhood trauma and implicated in premature mortality in humans. However, there is good news: emerging research has begun to reveal the power of meditation-based interventions in particular to restore telomeres and reverse this otherwise deadly alteration to the brain brought on by early life stress.