In the late 1960s, Romanian dictator Nicolae Ceaușescu enforced drastic population policies aimed at increasing birth rates. These measures led to thousands of children being placed in overcrowded orphanages, where they were deprived of emotional care and physical affection. Although deeply tragic, this event gave researchers a rare opportunity to study the profound effects of early-life trauma on human development.

Studies involving these institutionalized children revealed a consistent pattern: many had smaller brain volumes, which was linked to cognitive impairments. The longer children remained in these institutions, the more severe the brain atrophy became.

The Vulnerability of the Developing Brain

Childhood is a critical window for brain development, yet it can be disrupted by many forms of adversity, including neglect, abuse, or exposure to violence and conflict.

One of the key systems affected by early trauma is the hypothalamic-pituitary-adrenal (HPA) axis, which regulates stress responses. Researchers track its activity through hormones like cortisol, a glucocorticoid that helps the body respond to stress. While helpful in short bursts, chronic elevation of cortisol — common in children exposed to traumatic environments like war — can damage the body and brain over time. These children often also show heightened immune responses, indicated by elevated levels of immunoglobulin-A.

How Trauma Reshapes the Brain

Stress doesn’t impact the brain uniformly. One particularly vulnerable region is the hippocampus, which plays a vital role in memory and spatial processing. Because it contains a high density of stress hormone receptors, it’s especially sensitive to prolonged exposure to glucocorticoids. In children who had experienced three or more traumatic events, researchers found a significant reduction — around 17% — in hippocampal volume.

Different Types of Trauma, Different Brain Changes

Not all trauma is the same. Experts distinguish between:

• Trauma by commission – direct harm such as physical abuse or exposure to violence
  
• Trauma by omission – indirect harm from neglect or emotional deprivation
  

A 2019 review of neuroscience studies found that abuse (trauma by commission) tends to affect parts of the brain involved in threat detection and emotional regulation — such as the amygdala and insular cortex. These regions become hyperactive, which can lead to exaggerated fear responses and emotional dysregulation, traits often seen in post-traumatic stress disorder (PTSD).

Neglect, on the other hand, has been shown to impact the prefrontal cortex, which governs reasoning, decision-making, and impulse control. This was evident in the Romanian orphanage studies, where a lack of nurturing care led to delays in cognitive development and structural brain changes.

Interestingly, different types of adversity also influence how the brain matures. Research from 2018 showed that neglect slows brain maturation, whereas abuse may accelerate it.

Trauma’s Genetic Echoes

One of the most fascinating areas of research in recent years is epigenetics — the study of how life experiences can influence gene activity without altering the DNA sequence itself.

For children who have suffered maltreatment, scientists have observed abnormal patterns of gene expression: genes that are typically inactive become more active, and vice versa. This can result in « genetic ageing » where the biological profile of a child appears older than their actual age — a pattern linked to increased vulnerability to depression and other health risks.

Remarkably, some of these changes can begin before birth. A study following individuals whose mothers endured starvation during the 1944 Dutch famine discovered alterations in genes related to metabolism. Decades later, these individuals showed higher rates of obesity and abnormal blood lipid levels compared to siblings who had not been exposed to prenatal famine.

Hope Through Resilience

Despite the serious impacts of early trauma, the human brain retains a remarkable ability to adapt. Many children who experience adversity go on to recover and thrive — a process known as resilience.

Among the Romanian children who were later adopted into nurturing homes, many saw significant improvements in IQ and emotional functioning. Those removed from institutions before six months of age often developed on par with their peers.
Research into resilience is still evolving, but it’s beginning to highlight both biological and social factors that help buffer the long-term effects of trauma — and in some cases, even fuel post-traumatic growth, where individuals emerge from hardship with newfound strengths.