Adversity in childhood is a major risk factor for the development of psychological and behavioural problems later in life.
Sarah Baracz from Macquire University and Femke Buisman-Pijlman from University of Adelaide mention that higher rates of depression, suicidality, anxiety disorders, increased drug use, post-traumatic stress disorder and aggressive behaviour are seen in adults who have experienced traumatic experiences in childhood. These experiences can include emotional, physical and sexual abuse, neglect, and the loss of a parent or caregiver.
Traumatic childhood events can impact negatively on the development of the child’s brain. The following image is from a paper by Professor Bruce D Perry, Chief of Psychiatry at Texas Children’s Hospital. As seen on the image, the left is CT scan of the brain of a healthy 3-year-old with an average head size. The brain on the right is from a 3-year-old child with severe sensory-deprivation neglect. In the professor’s words: “The child’s brain is significantly smaller than average and has enlarged ventricles and cortical atrophy”.
However, not all children who experience early life trauma develop mental illness. The way you cope with stressful experiences is also influenced by your genes, coping responses and brain regulation. The most important brain chemicals involved in stress and emotional regulation are cortisol and oxytocin.
What is oxytocin?
Oxytocin is a hormone produced by the brain that promotes social relationships, emotional regulation. It is considered the ‘love hormone’ as is linked to the bond between a mother and child or between romantic partners.
The development of oxytocin starts in the womb and continues to develop after birth. Based on the experiences that we live, critical changes of this hormone can occur from infancy throughout adolescence.
Positive or negative experiences early in life can shape the oxytocin system. For example, exposure to nurturing and loving parents support the normal development of this system; adversity such as stress or illness, can affect the development and functioning of oxytocin and the oxytocin receptor.
Research has shown that early life stress can affect the oxytocin system leading to a high risk of developing drug dependence and a lower capability to cope with stress. A ‘healthy’ oxytocin system can offer greater resilience against addiction. Moreover, animal studies have shown how oxytocin can boost social connection, reduce anxiety and stress and lower the effect of drugs.
Early life stressors not only affect the oxytocin system, they also impact on important neurotransmitters and the stress system (cortisol). These changes affect ultimately our behaviour and our resilience to stress in adulthood.