Childhood Trauma and the Brain – Part 2

Perhaps one of the most dramatic examples of the damaging effects of childhood stress can be seen in the estimated 100,000 orphaned children in Romania after the rule of dictator Nicolae Ceauşescu’s regime. These children, many of them infants, were kept in state-run orphanages in very bleak conditions. They experienced deprivations of food, clothes, and general human warmth. They also were subject to many infectious diseases. One of these children later called these orphanages ““slaughterhouses of souls”.

Many of these children were eventually adopted into loving homes, but the damage had been done. As adults they showed many behavioural differences from other adopted adults who had not experienced this degree of deprivation as children. These behaviours included inattention problems, overactivity, and a variety of self-rated emotional problems.

These kinds of early-life stresses are by no means limited to unfortunate orphans. Studies done in 2017 and 2023 found that more than 60% of US adults had experienced at least one type of early-life stress. Furthermore, one sixth of the studied adults reported that they had experienced four different types of early stress. These stresses are associated with a higher risk of a variety of problems, including anxiety, depression, obesity and cardiovascular diseases. Vulnerability to addiction also appears in this list.

It’s clear from the Exeter study described in part one that childhood trauma changes the brain and seems to render it more vulnerable to addiction. It appears that the changes can occur at a number of levels within the nervous system.

Through an epigenetic mechanism trauma can alter gene expression, which can lead to permanent changes in how the brain responds to various experiences.  At the level of individual neuronal circuits, early stress can lead to significant changes in how circuits develop, including losing connections by synapses being lost. There are also positive epigenetic changes that early experiences can produce. I’ll describe these in part three of this series.

Researchers are now proposing that, based on the overall negative nature of these stresses, they be referred to with the general term “early-life adversity”. These are also now commonly referred to as “adverse childhood experiences (ACEs). This then encompasses a wide range of negative experiences. This includes those that adults do not typically perceive as stressful but children do, such as the unpredictability of sensory stimuli or events in their life. What’s surprising is that even if the events are positive, like being hugged or lifted up, it’s the unpredictable nature of these events that produce the stress.

It’s also clear that the effects of early stress are cumulative. It appears that it is rare for a child to completely recover from the effects of a given stress, and therefore additional stresses become progressively influential. Given that it’s virtually impossible to tease out the effects of stress on specific aspects of neural development in human children, researchers have developed important and effective ways to study these processes in animals, most often with rats. In part three, I’ll describe some of this important research.