On April 15, the Congress of Deputies approved the Organic Law for the protection of children and adolescents, an initiative that puts Spain at the forefront of defending the rights of minors.
It is a very necessary law in the face of a very serious problem in our society: negligence in care, physical and psychological abuse, sexual abuse, cyberbullying, bullying. The numbers of young people affected in our country are shocking. It must also be taken into account that these data are highly underestimated because in many cases abuse is not reported or is difficult to prove.
Abuse in the early stages of life is a risk factor for mental illnesses: it advances their onset and increases the severity of many of them. The effect on mood disorders, such as depression and bipolar disorder, is particularly important.
Recent analyzes have revealed that more than 45% of individuals with depression had suffered abuse early in life, and this percentage exceeded 50% in patients with bipolar disorder. This abuse carries a greater risk of suffering a first depressive episode earlier and a greater recurrence. Furthermore, it also predisposes to anxiety, a poorer response to therapy, and an increased risk of suicide. Coupled with all this, it is common for the same individual to experience different types of abuse (sexual, physical, emotional), the effects of which are cumulative and lead to more serious consequences on their mental health.
Impact on the brain
The first response to abuse in the initial stages of life involves raising awareness in society, detecting cases and protecting minors. However, also the study of its impact on the brain will allow us to develop strategies to identify it and improve and prevent its harmful effects.
The study of patients and laboratory animals is giving us clues to understand what happens in the brain of an abused individual.
One of the most important factors to take into account is that these adverse experiences occur during a period in which our brain is still completing its formation. Many of our neurons are just generating and refining their connections. This happens especially in regions like the prefrontal cortex (the most anterior part of our brain).
Therefore, abuse not only influences the functioning of neural circuits, but also modifies the final stages of their construction and, therefore, can lead to alterations that will last throughout our lives. These modifications are the ones that can lead to behavioral abnormalities that can ultimately turn out to be pathological.
There are several lines of research that have shown these alterations in individuals who suffered abuse, such as an increase in inflammation of their nervous system or alterations in the hypothalamic-pituitary-adrenal axis (the hormonal system that controls our response to stress).
Some genetic alterations have also been identified that could influence the vulnerability of our brain to abuse. In addition, neuroimaging has detected changes in neural connections and the structure of different areas of the brains of psychiatric patients who had suffered abuse, including the prefrontal cortex.
Animals help us understand the effect of abuse
Animal models are also very helpful in understanding what effects early life abuse has on the brain. We know that rodents develop abnormal behaviors if stressed during childhood and adolescence.
For example, studies carried out by Carmen Sandi at the Brain and Mind Institute of Lausanne and Cristina Márquez at the Institute of Neurosciences of Alicante have shown that these animals have more anxiety, are more aggressive and have learning defects.
Our team has observed how these changes are accompanied by alterations in neural circuits, especially in the prefrontal cortex. In a recently published study we have seen how stress during childhood and adolescence induces changes in the structure and connections of neurons in this brain region, especially inhibitory neurons: a type of neuron that plays a fundamental role in regulation of the functioning of our brain.
These alterations are particularly notable in female mice. This is interesting, because abused women in childhood have a higher risk of depression and anxiety than men. Although there are still few studies in this regard, this increased vulnerability could have both a biological basis and be a reflection of the greater stress load of women during life.
Therefore, we must continue researching to understand the effects of abuse in childhood and adolescence. But, above all, society must offer the maximum guarantees for the prevention and identification of these cases and the development of an effective system that detects, protects and avoids this scourge.