For decades we have heard that babies are like sponges. Now science proves this claim to be true. But this enormous ability to adapt to the environment is a double-edged sword. In the first years of life, neurons have enormous plasticity, which means that the brain can develop a great potential or, conversely, can suffer damage that is difficult to repair. And parents play a decisive role in tipping the scales in one direction or another.
The relationship that the parents establish with the child, their ability to satisfy his emotional needs and also his mood during the first years, influence the psychological development of the child and leave a deep mark that will probably accompany him throughout. the life.
In fact, several studies have linked maternal depression with the onset of mental disorders in children. It is also known that when parents have marital problems and often argue, their children become emotionally insecure and have difficulty establishing healthy relationships in adulthood. Furthermore, it has also been found that when parents are under severe stress, children are more likely to develop an emotional problem.
Now a new study conducted at the University of Wisconsin reveals that the problems are not limited to the psychological level, the stress of parents can also alter the genetics of their children by causing connections to form in their brains that will eventually affect the their reaction to adversity.
In fact, it's the first time that scientists have found a link between parental stress and children's DNA. This study shows that parents, and our experiences in general, can influence our genetics.
The stress response is also determined by genes
The idea that stress can damage DNA and brain development comes from research conducted in 2004 at McGill University. These researchers worked with guinea pigs and found that when mothers carefully cared for their young, a gene was activated that triggered a brain mechanism by which young mice developed greater tolerance to stress, i.e. they were able to adapt better. to changes, they were less fearful and were more likely to explore their environment.
Later, a Douglas Mental Health University Institute study with humans revealed that child abuse and parental neglect can also silence stress hormone receptors in the brain. It was observed that in children who were abused in childhood and who later committed suicide, the gene that was to activate the stress hormone receptors remained inactive.
The problem is that when this gene is silenced, the natural stress response system does not function properly, making it more difficult to cope with problems and adversities, and these people are more susceptible to developing psychological disorders and committing suicide.
In fact, another study conducted at the University of British Columbia revealed that when mothers are depressed or anxious, the gene responsible for activating stress hormone receptors tended to remain inactive in infants. As a result, these children will be more fearful, find it more difficult to adapt to changes, and have problems coping with stressful situations. Or they will be rude children.
Stressed mothers, less resilient children
This new study reveals that children do not need to be physically abused for certain DNA changes to occur. These researchers have analyzed hundreds of parents for more than a decade. Parents completed a series of questionnaires at different times in their children's lives: when they were babies, at 3 and 4 years of age, and later when they reached adolescence. Using the questionnaires, the researchers assessed the parents' stress level. After they turned 15, the scientists analyzed the DNA of 109 teenagers.
They found differences in the DNA of the young people whose parents showed higher levels of stress. It was also noted that the stress of both parents did not affect the same way. Indeed, a high level of stress in mothers during the infants' early years was linked with alterations in 139 genes. Paternal stress was less important, although it could be linked to changes in 31 genes. This difference may be due to the fact that many fathers are less involved in raising their children, so the impact of their emotional state is likely to be less.
Another important finding indicates that stress in mothers and fathers does not cause significant changes in the expression of infant genes after 3 years of age. This could be due to the fact that the first three years of life are the phase of maximum brain plasticity, when the regions of the brain are able to adapt more and also take on the functions of other sectors if you suffer any brain damage. From this age on, the brain continues to change but does so at a slower rate.
Among the genes altered (normally silenced) by stress, two are particularly important for brain development and behavior, as they are linked to cellular communication and neural membranes. One of the genes involved is Neurog1, which stimulates the growth of new neurons, which is critical for development, learning and memory.
The researchers explain that these changes in DNA expression affect the way neural connections are established and thus, the functioning of the brain. In practice, by silencing the gene responsible for activating stress hormone receptors, the child will not have the necessary neurological tools to deal with difficult situations. If there are not enough receptors for hormones such as cortisol and adrenaline, they remain active, causing damage to the body, while the brain is unable to find an adequate solution. Therefore, the child is likely to be more irritable, impulsive and fearful.
However, it should be made clear that our brains have surprising plasticity, so despite changes in gene expression it doesn't mean that these children can't learn to manage stress assertively by developing a more resilient attitude once they reach adolescence or adulthood, but it will be more difficult.
In any case, the message for parents is clear: stress is harmful not only for adults but also for children, especially if they are very young.
