In 1966, Romanian dictator Nicolae Ceaușescu introduced extreme policies to increase the country’s birth rate. This led to mass abandonment of children, who ended up in orphanages in appalling conditions, where they received no care, attention or love. Although tragic, this infamous “natural experiment” has allowed us to learn a lot about the effects of early life trauma on the brain.
Research on these children showed that many of them had small brain volumes, which partly explains their poor cognitive performance. This atrophy was more severe in children who had spent more time in institutions.
Childhood is the most sensitive period for neurodevelopment, but sadly it can be disrupted in many ways, from abuse or neglect to exposure to war and violence.
question of tension
Understanding the neurobiological effects of childhood adversity may help us understand and treat its long-term psychological effects. Evidence suggests that these specifically affect a key stress regulation system, known as the hypothalamic-pituitary-adrenal axis. The activity of this system can be measured through hormones such as cortisol, collectively known as glucocorticoids.
In normal amounts, cortisol helps energize the body to respond to threats or challenges. However, excessive amounts can be harmful – children exposed to war have elevated levels of both cortisol and immunoglobulin-A in their saliva, which also indicates higher immune system activity.
changes in brain
Traces of adverse conditions may also be more localized in the brain. One of the areas most sensitive to the effects of stress is the hippocampus, a structure important in the formation of memories and spatial orientation, among other functions.
This sensitivity is due to higher concentrations of glucocorticoid receptors, “stress hormones” that are present at higher levels in families exposed to war.
The largest and most recent study on the topic reported a 17% reduction in hippocampal size among children exposed to three or more traumatic events compared to children who had not experienced any trauma.
two types of trauma
It is important to note that adversity varies not only in severity, but also in its type. Abuse or ill-treatment causes injury by commission, while neglect or deprivation causes injury by omission.
A 2019 systematic research review found that adverse conditions created by commission – such as exposure to physical or sexual abuse or gender-based violence – affect limbic and paralimbic structures, including the amygdala and insular cortex.
These areas are part of the brain’s “alert system”, and due to abuse they are constantly overactive. This, in turn, causes excessive reactions to harmless stimuli, as seen in post-traumatic stress disorder.
In contrast, neglect affects prefrontal areas of the brain, which are responsible for more complex processes like planning and reasoning. The latter was clearly seen in the above study of state-fostered children in Romania, where lack of care resulted in brain atrophy and cognitive decline.
Different types of adversity can also affect development in opposite ways: a 2018 study found that neglect slows maturation, while abuse accelerates it.
Genetic footprint of childhood adversity
One of the most astonishing discoveries of this century is that conditions and environment can alter genetic mechanisms. This occurs through a process called epigenetics, whereby certain genes are expressed to a greater or lesser extent depending on a person’s environment.
For example, abused children have been found to have the opposite of expected gene expression (high expression of genes that normally have low activity, and vice versa).
Abuse in childhood also causes “genetic aging”: a pattern of genetic expression that is more advanced than normal for a person’s age. The risk of depressive symptoms also increases with age.
Another surprising discovery is that some epigenetic changes may occur during embryonic development. A study on the tragic Dutch famine of 1944 found that people whose mothers experienced starvation during early pregnancy showed changes in the expression of genes related to metabolism.
This, to some extent, explains their increased body mass index and blood triglycerides compared to siblings who were luckier and did not suffer from hunger while in the womb.
Neurobiology of Resilience
It’s important not to be defeatist: the brain is highly malleable, and many individuals can overcome early adversity. In psychology this process is called flexibility.
In a group of adopted Romanian children, a decline in IQ was observed in the years following foster care until they reached normative levels. Furthermore, those who were in these institutions for less than six months had standard values for all the variables studied from the beginning.
Research on resilience is only beginning to reveal the neurobiological and psychosocial factors that moderate the effects of acute and chronic stress. In some people, it can also enable what is known as post-traumatic growth.
,Author: Macia Buedes Rotgar, Professor Lector (equivalent to Audante Doctor) Psychología Specializado in Neuroscientifica Cognitiva, Affective, y Social, University of Barcelona,
,disclosure statement: Macia Buedes Röttger receives funding from the Brain and Behavior Research Foundation)
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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