Recent research published in biological psychiatry present evidence that experiencing abuse or neglect in childhood is associated with specific physical changes in brain structure that vary by age and gender. This study suggests that these structural differences are most pronounced during young adulthood, with young women exhibiting the most extensive brain changes after early life adversity.
A broad international team of researchers representing dozens of institutions in eight countries initiated this study to better understand the relationship between childhood adversity and brain development. Many people who experience abuse in childhood eventually develop stress-related mental health conditions such as major depressive disorder and post-traumatic stress disorder.
Past studies have often looked at the brains of people with these mental illnesses, without distinguishing between the effects of the mental illness and the effects of childhood trauma itself. The researchers wanted to isolate the physical effects of abuse across different stages of a person’s life and examine how the brain adapts to stress.
“Early childhood adversity, particularly childhood maltreatment, remains one of the strongest risk factors for mental illness,” said study author Tiffany C. Ho, associate professor at the University of California, Los Angeles, and director of the Cognitive, Emotional, and Neurodevelopmental Division at the Youth Research Institute.
Prominent psychological theories distinguish between adversity characterized by active threat, such as physical abuse, and adversity characterized by deprivation, such as emotional neglect. Threat-related trauma tends to affect areas involved in fear learning and stress regulation. Deprivation-related neglect often affects circuits that handle reward processing and social functioning.
To measure these subtle changes, the researchers used a technique called normative modeling. This approach tracks brain development, similar to how pediatricians use growth curves for children’s height and weight.
Creating a standard model of normal brain variation across different ages and genders could pinpoint where trauma-exposed brains deviate from expected developmental patterns. This method helps distinguish true trauma responses from normal biological differences between individuals.
To conduct the study, researchers analyzed data from 3,711 participants across 25 international locations in eight countries. The sample included 1,389 patients diagnosed with major depressive disorder or post-traumatic stress disorder and 2,322 healthy participants. The average age of the combined group was 33.3 years, and 59.9 percent of participants were female.
Participants completed a self-report survey called the Childhood Trauma Questionnaire (Short Form). This assessment measures the severity of mental, physical, and sexual abuse, as well as physical and emotional neglect. Scientists separated scores for general abuse and general neglect to see whether different types of trauma produce different physical effects.
The scientists then used magnetic resonance imaging, commonly known as MRI, to take highly detailed pictures of the participants’ brains. They measured 14 subcortical volumes that represent the size of the brain’s deep internal structures.
They also collected 68 measurements of cortical thickness and 68 measurements of surface area. Cortical thickness refers to the depth of the wrinkled outer layer of the brain, while surface area refers to the amount of total space covered by the folded outer layer.
The researchers divided the participants by gender and divided them into three different age groups. These groups included the pediatric cohort aged 18 years and younger, young adults aged 18 to 35 years, and older adults aged 35 years and older.
The data revealed that childhood maltreatment is associated with specific brain biases that are highly dependent on both biological sex and developmental stage. The strongest structural differences were observed in young adult women.
In this particular group, more severe abuse and neglect correlated with a smaller hippocampus and smaller putamen. The hippocampus is a deep region of the brain deeply involved in memory and learning, and the putamen helps regulate movement and learning.
Young women who experienced trauma also showed thinner entorhinal cortex, an area essential for navigating physical space and processing time. Additionally, they showed an increase in the surface area of the orbitofrontal cortex, a region at the very front of the brain that helps control emotions and complex decision-making.
For male participants, structural changes varied significantly depending on the specific type of trauma. Young adult men with a history of abuse showed a wide range of differences, including a thicker medial orbitofrontal cortex.
These men also showed larger volumes in the thalamus and globus pallidus. The thalamus acts as a major relay station for sensory information, and the globus pallidus is involved in motivation and behavior. In contrast, neglect had very weak associations with brain structure in men.
The researchers found no significant trauma-related structural brain differences in the pediatric group. They point out that the physical effects of early life adversity can remain dormant during childhood until fully manifesting in early adulthood.
Some brain regions in adults showed larger structures, while others were smaller than the standard growth curve predicted. This opposite pattern suggests that the brain tends to actively reorganize neural circuits to cope with trauma over time.
“The neuroanatomical scar of childhood abuse is not monolithic; its impact varies depending on the form of adversity experienced (e.g., abuse and neglect), gender, and age,” Ho told SciPost. “Overall, young adult women show more widespread effects of abuse on brain structure, whereas the effects of neglect are much more limited, and these patterns persist at a smaller scale in older age.”
“Young adult males, like females, exhibit some of the structural brain changes associated with childhood maltreatment, but in contrast, childhood neglect experiences in males appear to have minimal effects on the neuroanatomical features examined in this study.”
This study provides an extensive investigation into trauma and brain structure. However, as with all studies, there are some limitations. Because this study relies on cross-sectional data, data that captures a single, timely snapshot of each individual, it cannot conclusively prove that childhood maltreatment directly caused these brain changes.
Self-report surveys also rely on participants’ personal memories, which can sometimes be inaccurate. The survey also misses other forms of early adversity, such as exposure to environmental toxins and severe housing instability.
The lack of findings in the pediatric group may simply be due to the small sample size of 349 children. The scientists suggest that this particular group may not have had enough statistical power to detect subtle physical differences in the developing brain.
Future studies could follow the same individuals over several years to see in real time how trauma changes brain development. Scientists also aim to investigate whether these distinct physical differences can predict how well patients will respond to psychological and medical treatments.
Ultimately, understanding these unique brain patterns could help doctors design more personalized treatments for individuals who have experienced adversity early in life. Recognizing how trauma shapes the brain is a necessary step to providing better care.
“My research focuses on the neuroscience of human adversity, stress and depression,” Professor Ho said. “One of the more surprising findings of my research is that the effects of depression and other similar conditions (such as PTSD) on the brain are quite small and may even be partially explained by the effects of early life adversity on the brain.”
“At the same time, it is remarkable how common experiences of childhood adversity and childhood abuse are, and that most people who are exposed do not necessarily develop a mental illness. This speaks to how adaptable and resilient the human brain is.”
The study, “Childhood Abuse and Deviations from Normative Brain Structure: A Large-Scale Analysis of 3,711 Individuals from the ENIGMA MDD and ENIGMA PTSD Working Groups,” was authored by Haley R. Wang, Zhen-Qi Liu, Elena Pozzi, Ahmed Hussain, Priyanka Sigar, Chadi Abdallah, Nina Alexander, Justin Baker, and Jochen. Bauer, Jennifer Urbano Blackford, Josh Sisler, Colm G. Connolly, Andrew Cotton, Judith Daniels, Udo Dunrowski, Maria Densmore, Terry DeLune Cassini, Danai Dima, Stefa N du Plessis, Amit Etkin, Negar Fani, Lucas Fisch, Jacquelyn Fitzgerald, Thomas Frodl, Cynthia HY Fu, Alisafet Gonul, Evan M. Gordon, Ian Gotlib, Roberto Goya- Maldonado, Ninke A. Groenewald, Dominique Grotegert, Tim Hahn, J. Paul Hamilton, Laura Hahn, Ilan Harpas-Rotem, Courtney C. Haswell, Ryan Herringa, Julia Herzog, Jonathan Ipser, Neda Jahanshad, Tanja Jovanovic, Milissa Kaufmann, Tilo Kircher, Maximilian Konowski, Sheri-Michelle Kupowitz, Axel Krug, John Crystal, Ruth Lanius, Christine Larson, A. Mit Lazaroff, Lauren Lebois, Elizabeth Lehr, Yifat Levy, Meng Li, Antje Mansey, Adi Maron-Katz, Andrew McIntosh, Katie McLaughlin, Suzanne Meinert, Benson Mwangi, Stee Bun M. Nelson, Igor Nenadic, Yuval Nelia, Richard Neufeld, Amar Ojha, Bunmi Olatunji, Elizabeth A. Olson, Nils Opel, Matthew Peverill, Kelly Ressler, Marisa Ross, Isabel Rosso , Matthew Sachet, Kelly Sambrook, Christian Schmar, Soraya Seedat, Martha E. Shenton, Maurizio Cicorello, Annika Shirk, Jair C. Soares, Dan J. Stein, Frederike Stein, Murray B. Sta. Yin, Benjamin Suárez-Jiménez, Jean Theberge, Sofia I. Tomopoulos, Carissa Thomas, Paula Usman, Lee L. van den Heuvel, Sanne van Rooy, Henrik Walter, Martin Walter, Xin Wang, Heather Whalley, Nils R. Winter, Mon-Ju Wu, Hong Xie, Tony Yang, Xi Zhu, Sigal Zilcha-Mano, Giovana B. Zunta-Soares, Sophia Frangou, Paul M. Thompson, Lauren Salminen, Delin Sun, Rajendra Morey, Jennifer S. Stevens, Lianne Schmaal, and Tiffany C. Ho.
