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A longitudinal neuroimaging study conducted in Brazil found that individuals who were exposed to maltreatment during childhood tended to have a smaller volume in the right hippocampus—a brain region important for memory and emotional regulation. This reduced volume persisted throughout adolescence and remained even after accounting for symptoms of depression. The findings were published in Psychological Medicine.
Childhood maltreatment refers to abuse or neglect experienced by a child. It can include physical, emotional, and sexual abuse, as well as physical and emotional neglect. Such experiences may occur within families or institutional settings and often involve a violation of trust and safety.
Exposure to maltreatment early in life can disrupt healthy brain development, affect stress regulation, and impair emotional processing. Children who experience maltreatment are at increased risk for mental health conditions, including depression, anxiety, posttraumatic stress disorder, and personality disorders. They may also face difficulties in forming healthy relationships and struggle with self-esteem and emotional regulation.
Building on prior research linking childhood maltreatment to altered brain development, study author Victoria Fogaça Doretto and her colleagues set out to examine how such experiences might influence hippocampal volume over time. The hippocampus, located in the medial temporal lobe, plays a key role in forming and retrieving memories and is also involved in spatial navigation and emotional regulation.
The researchers analyzed data from the Brazilian High-Risk Cohort Study, which began in 2009 and included children aged 6 to 12 from 57 schools in the cities of São Paulo and Porto Alegre. The current analysis focused on data from 795 participants, 43% of whom were girls. The average age of participants at the start of the study was 10 years.
At baseline, both children and their parents completed questionnaires assessing childhood maltreatment, including experiences of physical abuse, sexual abuse, emotional maltreatment, and neglect. Participants underwent psychiatric assessments and returned for follow-up visits three and six years later, at which point magnetic resonance imaging was conducted to assess brain structure.
The results showed that 23% of the children had experienced at least one type of maltreatment. Approximately 4% exhibited symptoms of depression, while 31% displayed symptoms of some form of mental disorder.
Children who had experienced higher levels of maltreatment at the beginning of the study tended to show smaller volumes in the right hippocampus at later neuroimaging time points. This association remained significant even after controlling for depressive symptoms. In contrast, no relationship was found between maltreatment and the volume of the left hippocampus.
“The present study showed that childhood maltreatment is associated with persistent reduction of hippocampal volume in children and adolescents, even after adjusting for the presence of major depressive disorder and genetic determinants of hippocampal structure,” the study authors concluded.
The study sheds light on the specificities of brain anatomy of individuals who experienced maltreatment as children. However, it should be noted that the design of this study does not allow any definitive causal conclusion to be derived from the results.
The paper, “Childhood maltreatment and the structural development of hippocampus across childhood and adolescence,” was authored by Victoria Fogaça Doretto, Ana Beatriz Ravagnani Salto, Sandra Schivoletto, Andre Zugman, Melaine Cristina Oliveira, Marcelo Brañas, Marcos Croci, Lucas Toshio Ito, Marcos Santoro, Andrea P. Jackowski, Rodrigo A. Bressan, Luis Augusto Rohde, Giovanni Salum, Eurípedes Constantino Miguel, and Pedro Mario Pan.
