A new neuroimaging study conducted by psychologists at the University of California, Los Angeles (UCLA) has shown that abuse suffered in childhood leaves scars on the brain. Researchers have found correlations between the severity of different forms of maltreatment and the cortical thickness, surface area, and subcortical volume of the brain, based on magnetic resonance images of individuals. The effect was more pronounced in young women than in men and children. The results were published in Biological Psychiatry.
First author Haley Wang, currently a postdoctoral researcher in the UCLA Department of Psychiatry, collaborated with an international research collective called the ENIGMA Consortium to examine brain magnetic resonance images of 1,389 patients with posttraumatic stress disorder (PTSD) and major depressive disorder (MDD), along with 2,322 healthy control subjects. The images came from eight different countries. The team measured different dimensions of the brain, such as the thickness of the outermost layer, called the cortex, and the volume of the innermost layers, called the subcortex, as well as the total surface area of the brain. Participants responded to a standard questionnaire to retrospectively assess physical, emotional, sexual abuse, physical neglect, and emotional neglect experienced during childhood. Based on this data, the researchers developed two scores: one to reflect the overall severity of childhood abuse and one to reflect the overall severity of childhood neglect. Neglect was scored separately from abuse, in order to distinguish it from the effects of trauma.
Using an index that researchers have collected over the years of typical brain growth and development — a sort of growth chart for the brain — the researchers discovered a distinct, but not uniform, set of structural differences in the brains of individuals who scored high on childhood maltreatment. These differences suggest that the neurodevelopmental trajectories of these brain regions were altered following the experience of such adversity. More severe abuse was associated with unusually larger thalamus and pallidum volumes, smaller cingulate cortex isthmus regions, and larger medial orbitofrontal cortex surface area than expected for their age. More severe abuse was associated with more dramatic changes in these brain regions, particularly among young women. Many of these patterns observed in young women persisted in older women as well.
Neglect had more limited effects on brain structure: in young women, it was limited to surface area deviations mainly in the cingulate regions, located in the central part of the brain near the corpus callosum, while in young men the effects were limited to the smaller right middle temporal cortex, located in the lower right part. The findings challenge the idea that childhood trauma has a unique, static effect on the brain. In contrast, different types of adversity experienced in early childhood could be associated with a variety of changes in brain structure, which depend on age and gender.
