Childhood Trauma Causes Long-lasting Changes in Brain Architecture
News Editor: Tina Pentland
While it is generally well-recognised that various forms of childhood abuse are risk factors in the development of psychological problems including mental illness and sexual dysfunction in adult life, the exact mechanisms mediating this link are still poorly understood. However, a recent study of adult women who were abused in childhood, has now found that structural changes in areas of the brain associated with sensory awareness and physical and emotional response—the somatosensory cortex—may provide that link. The study, “Decreased cortical representation of genital somatosensory field after childhood sexual abuse”, published in the American Journal of Psychiatry, was developed specifically to test a hypothesis that sexual dysfunction is linked to changes in brain structure that occurred in childhood, due to abuse. The results of the study were quite startling because not only did the researchers find a link between structural changes in the brain and adult sexual dysfunction, they also found that different areas of the brain which regulate different types of behaviour were affected, according to the type of abuse the victim had suffered earlier. A possible explanation for these findings is that changes in the brain, which can be attributed to neural plasticity during the brain’s development, function as a defence mechanism to de-sensitise the abuse victim in childhood but that such changes contribute to differential behaviour in later life—precisely because the areas of the brain responsible for various types of sensory perception and response are no longer sensitive to normal inputs.
An international team of researchers from the Miller School of Medicine at the University of Miami, the Institute of Medical Psychology at Charité University of Medicine, Berlin, and the McGill Centre for Studies in Aging, carried out the study in collaboration with scientists at Emory University in Atlanta. In order to test their hypothesis linking changes in brain architecture and later dysfunction, the team examined the brains of 51 adult women who had been exposed to various forms of abuse in childhood, using magnetic resonance imaging (MRI) to identify the precise location of the sensory fields in question, and “cortical thinning” as the dependent variable. The extent of the emotional and sexual abuse, which could be linked to the degree of cortical thinning, was measured according to a scale based on the Childhood Trauma Questionnaire (CTQ) where age, depression and all other CTQ subscales were controlled.
This study is one of the first to document long-term alterations in specific brain areas as a consequence of child abuse or neglect. The authors hope that it will provide useful insights into developing appropriate treatments for people who carry a lifelong burden of psychiatric or psychological problems due to childhood trauma.