A new study recently published in the American Journal of Psychiatry has found an association between child abuse and the reduction of gray matter in the brain that is responsible for information processing.
Child abuse, also referred to as child maltreatment, describes all forms of physical and emotional abuse, sexual abuse, neglect, negligence and any other exploitation that harms the health, development, dignity or survival of a child under the age of 18 years.
The World Health Organization (WHO) state that worldwide, around 20% of women and 5-10% of men report being sexually abused as children, while 23% of individuals report being physically abused during childhood.
Past research has established that child abuse can lead to alterations in brain structure. But the team involved in this latest study, including Joaquim Radua, a researcher at FIDMAG Sisters Hospitallers Foundation for Research and Teaching in Spain, says neuroimaging studies investigating the extent of these alterations have been “inconsistent.”
With this in mind, the researchers set out to see just how much child maltreatment influences brain structure.
Findings show ‘serious consequences of child abuse on brain development’
The team analyzed the data of 12 studies that used voxel-based morphometry (VBM) – a neurorimaging method that assesses differences in brain anatomy between two groups of individuals.
The studies included 56 children or adolescents and 275 adults with a history of childhood abuse, as well as 56 children and 306 adults who had not been exposed to childhood maltreatment.
Using a 3D meta-analytical neuroimaging technique created by Radua – called “signed differential mapping” – the team was able to determine the volumes of gray matter in each individual.
They found that the individuals who had been exposed to childhood maltreatment had much smaller volumes of gray matter in certain brain areas, compared with those who had no history of child abuse.
In detail, those who had a history of child abuse had reduced gray matter in their the right orbitofrontal/superior temporal gyrus, amygdala, the parahippocampal and middle temporal gyri and the left inferior frontal and post central gyri.
The team notes that the most consistent reduction of gray matter volume among those exposed to child abuse was in the ventrolateral prefrontal and limbic-temporal regions – areas linked to cognitive control.
Since these brain regions develop relatively late – after the child abuse may have occurred – the team says this may explain why some victims of child abuse typically have compromised cognitive control.
In addition, the team found that reductions in gray matter in the right orbitofrontal-temporal-limbic and left inferior frontal regions of those with a history of child abuse remained even among those who were unmedicated, “indicating that these abnormalities were not related to medication but to maltreatment,” says Radua.