Researchers link maltreatment in children with lower brain volumes

German researchers have conducted a neuroimaging study of toddlers who experienced childhood maltreatment, finding that those who had experienced such abuse in the six months prior to scans being taken had lower total brain volume. This was primarily due to smaller gray matter volume and was associated with lower cognitive abilities. 

 

Childhood maltreatment refers to various forms of abuse and neglect experienced by children under the age of 18 years. It encompasses physical, emotional, and sexual abuse, as well as physical and emotional neglect. 

 

Such maltreatment can have long-lasting effects on a person’s mental and physical health, with previous studies indicating that such experiences can lead to conditions such as depression, anxiety, substance abuse, and chronic health conditions later in life. 

 

One of the possible mechanisms through which these effects of maltreatment develop is thought to be through changes to the structure and function of the brain, with the brains of children being particularly vulnerable given their still developing state. 

 

Studies on both humans and animals reported associations between childhood maltreatment and variations in brain structure, function, and connectivity.

 

Published in Neurobiology of Stress, the study explores whether maltreatment severity is associated with global brain volume and volumes of specific areas and tissues in the brains of children. 

 

Study author Judith Joseph and her colleagues were also interested in whether these differences in brain volume are associated with the intellectual ability of children. The researchers hypothesized that both brain volume and intellectual ability are related to the severity of maltreatment, expecting that children who have been more severely maltreated will exhibit lower volumes of specific brain tissues and overall brain volume, as well as diminished intellectual abilities.

 

To reach their findings the researchers explored brain scans of 86 children aged between three and five years, who had experienced physical and emotional abuse and/or neglect in the six months prior to the study. The children were recruited from a wide range of local child welfare and protection services.

 

Caregivers were interviewed by trained clinicians to gauge the severity of the maltreatment experienced, covering the degree of sexual abuse, physical abuse, emotional maltreatment, and three subtypes of neglect: failure to provide, lack of supervision, and moral, legal, and educational maltreatment which children may have endured. 

 

At the beginning of the study and again 12 months later, the children underwent cognitive ability tests. Fifty-one of the children also underwent magnetic resonance imaging of their brains.

 

The results indicated that children who had experienced more severe maltreatment tended to have smaller brain volumes. Specifically, an increase in maltreatment severity by one standard deviation was associated with a 3.61 per cent decrease in intracranial volume. In terms of specific brain tissues, children who were more severely maltreated generally had lower gray matter volume, which correlated with lower intellectual abilities both at the beginning of the study and one year later.

 

“Greater maltreatment severity in early childhood is related to smaller brain size at a very young age with significant consequences for intellectual ability, likely setting a path for far-reaching long-term disadvantages,” the researchers note. 

 

“Insights into the molecular and neural processes that underlie the impact of maltreatment on brain structure and function are urgently needed to derive mechanism-driven targets for early intervention,” they concluded.

 

Greater maltreatment severity is associated with smaller brain volume with implication for intellectual ability in young children using the link provided.