Child abuse can reduce the volume of grey matter in the brain that is responsible for processing information, a new study has found.

The study, by experts at London's King's College and the FIDMAG Sisters Hospitallers Foundation for Research and Teaching in Spain, analysed the association between childhood maltreatment and the volume of cerebral grey matter.

"Childhood maltreatment acts as a severe stressor that produces a cascade of physiological and neurobiological changes that lead to enduring alterations in the brain structure," said Joaquim Radua, a researcher at FIDMAG.

In order to understand the most robust abnormalities in grey matter volumes, the research team, which included the National University of Singapore, carried out a meta-analysis of the voxel based morphometric study on childhood maltreatment.

VBM is a neuroimaging analysis technique that allows investigation of focal differences in brain anatomy comparing magnetic brain resonance of two groups of people.

The study included twelve different groups of data made up of a total of 331 individuals (56 children or adolescents and 275 adults) with a history of childhood maltreatment, plus 362 individuals who were not exposed to maltreatment (56 children or adolescents and 306 adults).

In order to examine the cerebral regions with more or less grey matter volumes in maltreated individuals, a three-dimensional meta-analytical neuroimaging method was used called 'signed differential mapping' (SDM), developed by Radua.

Relative to comparison subjects, individuals exposed to childhood maltreatment exhibited significantly smaller grey matter volumes: in the right orbitofrontal/superior temporal gyrus extending to the amygdala, insula, and parahippocampal and middle temporal gyri and in the left inferior frontal and postcentral gyri.

"Deficits in the right orbitofrontal-temporal-limbic and left inferior frontal regions remained in a subgroup analysis of unmedicated participants, indicating that these abnormalities were not related to medication but to maltreatment," said Radua.

The abnormalities in the left postcentral gyrus were found only in older maltreated individuals.

These findings show that the most consistent grey matter abnormalities in individuals exposed to childhood maltreatment are located in ventrolateral prefrontal and limbic-temporal regions.

These regions have relatively late development, i.e. after the maltreatment and the malfunction could explain the affective and cognitive deficit of people with a history of child abuse, researchers said.

The study was published in the American Journal of Psychiatry.