Childhood Trauma Leaves Lasting Marks on the Brain
Sensitive periods
Martin Teicher, a researcher at Harvard Medical School, agrees with the ACE team that there must be some biophysical pathway altered by childhood abuse. Since discovering more than a decade ago that victims of abuse showed abnormal electroencephalograms (EEGs), he has been studying alterations in brain structure and function linked to adverse childhood experiences.
“Early childhood maltreatment acts as a stressor,” said Teicher. “It can result in a cascade of physiological changes to the brain. And by affecting how the developing brain is structurally and functionally wired, that childhood abuse leads to the emergence of psychiatric disorders.”
But not every person exposure to childhood trauma develops psychiatric problems. Teicher’s research suggests there are particular “sensitive periods” where abuse can derail normal brain development, leading to those later issues.
“We’ve found that the hippocampus is particularly vulnerable to abuse at three to five years of age, the corpus callosum between nine and ten and the prefrontal cortex between fourteen and sixteen years of age. These areas are linked [respectively] to depression, suicide attempts, and addiction,” says Teicher. “We’re trying to hone in on the timing of exposure of abuse and its effects on the normal trajectories of brain development.”
His lab has found that the type of abuse is also important. “Specific types of abuse seem to affect the cortical regions and sensory pathways involved in relaying and processing that aversive information,” says Teicher. “Witnessing domestic violence, for example, affects gray matter in the visual cortex and affects pathways that convey information from the visual system to the limbic system. In contrast, psychological abuse and bullying makes changes to development in auditory processing pathways.”
Teicher believes the data is clear—ACEs play a pivotal, biological role in later psychopathology and other negative health outcomes. And as we learn more about how they do so, he argues, doctors need to be very aware of childhood histories to make sure those with depression or other health issues are treated correctly.
“If the neurobiology of individuals with a history of childhood trauma is different, then the way these individuals respond to typical treatments is also going to be different. And that’s critical to finding the right therapy,” he says. “Individuals with childhood abuse and major depression will have a much poorer response to drug treatment, for example, than those without that history. That means that history is a critical determinant in how to approach their treatment and should never be underestimated.”
