Childhood cruelty changes the structure of the brain

The team, led by psychology professor Tiffany Ho, sought to understand whether it is possible to speak of a kind of neurobiological scar that remains after traumatic experiences in childhood. After all, it is known that abuse in early years significantly increases the risk of developing stress‑related disorders, such as depression or post‑traumatic stress disorder. At the same time, the child’s brain is particularly vulnerable: it actively forms key neural networks and is characterized by increased plasticity, which is why external influences can significantly alter its developmental trajectory.

For the analysis, researchers from UCLA, together with the international ENIGMA consortium, examined MRI scans of more than 3,700 people — among them were 1,389 patients with PTSD and major depression and 2,222 healthy participants. The experts assessed several parameters at once: the thickness of the cerebral cortex, the total surface area of the brain, and the volume of subcortical structures. To separate the effects of different types of adversity, the participants completed a standard questionnaire that allowed them to retrospectively assess the physical, emotional, and sexual abuse they experienced in childhood, as well as physical and emotional neglect. Based on the responses, two separate indicators were created — the total severity of abuse and the total severity of neglect: this helped to see how these types of adverse experiences affect the brain in different ways.

It turned out that the more severe the abuse was, the more noticeable the changes in certain areas of the brain were. Thus, people with high levels of violence severity exhibited increased volumes of the thalamus and globus pallidus, smaller sizes of the isthmus of the cingulate cortex, and a larger surface area of the medial orbitofrontal cortex compared to what is typically observed in people of their age. At the same time, the changes were distributed unevenly: in some areas the cortex became thinner, while in others it became thicker; some structures increased in size, while others decreased. This suggests that adverse experiences alter its development according to complex, heterogeneous patterns.

These effects were especially pronounced in young women: their structural changes were more pronounced than in men or children, and in many cases persisted at an older age. Scientists suggest that this may be due either to a higher proportion of sexual violence among girls during sensitive periods of development, or to the fact that the female brain, in principle, may react differently to trauma. However, the exact reasons have yet to be clarified.

Neglect, in turn, produced more local effects. In young women, deviations in the surface area of the brain mainly affected the cingulate regions located next to the corpus callosum, and in young men, a small area of the right middle temporal cortex.

The work refutes the idea that childhood trauma affects the brain in a single, universal way. On the contrary, different types of adversity at an early age are associated with different sets of structural changes, and these changes also depend on a person’s gender and age. At the same time, it is important to remember that the revealed differences in the structure of the brain do not directly indicate the specific cognitive, emotional or behavioral abilities of an individual.The study was an important step towards understanding how difficult childhood experiences can rebuild the brain during growth.