The Impact of Childhood Stress

I have often been asked by colleagues why I use neuro-biological instead of psychological concepts to explain developmental processes. My answer is always that neuro-biological concepts can be 'seen' on MRI scans and we become more understanding of how our brain works. I find that exciting.

So why is childhood stress (hardship, abuse, neglect) so damaging? Why can people not follow the often given advise and just 'GET OVER IT'? She short answer is: Because stressful experiences become part of who you are! Let me show you how that works: (Disclaimer: I am really not a neuro scientist and don't claim to be an expert. I'll give you my 'lay translation' of hundreds of research articles and books that I have studied).

A child is born with a few neuro pathways necessary for the basic functioning. However, it is pretty much a clean slate with only a few connections. From here on, each experience the baby has will create a new connection. This seems to include even some pre-birth experiences. Through the interpersonal experiences with an attuned and caring parent the child is able to develop neural networks that will assist it to integrate affective states, sensations, behaviours, and consciousness.

With 'good enough' care these networks will become functional connections that give the growing child the ability to cope with increasing levels of stimulation and arousal. We can say that the human brain grows as the child deals with increasingly complex situations by which it is challenged and that provide new learnings. Thus the development of the brain is not just a thing that happens by itself. It doesn't grow like hair or fingernails do. Positive and negative interactions with significant others are represented in neurological networks and become structures of our brains.

By the time a child is six years old, the neural networks in the brain look like an impenetrable maze, whereby each connection and cross-connection represents experiences the child has had. However, this is not all there is. These neural networks are also involved in the child's construction of the self. They form the matrix for the developing personality through the weaving of conscious and unconscious experiences of somatic, temporal, or interpersonal nature that then become the narrative of the person's self and identity. When a child a loved and cared for by, lets say, parents and the extended family it will grow up feeling OK and safe and it will be trusting and engaging with people, it will have a positive outlook, and learn easily. Being cared for and loved has become part of its personality and identity.

Just as positive interpersonal experiences are associated with building neural structures that assist with the regulation of affective states and the development of a positive sense of self, the absence of these experiences is connected with lacking these structures. Growing up in an environment of abuse and/or neglect may cause the neural development of the child to be interrupted, arrested, or reversed, leading to the inability to regulate and control states of arousal and subsequently to a lack of self-confidence. Indeed, research using brain-scans has revealed that children with a history of abuse or neglect had brains that were less developed and smaller in size than brains of children from supportive families.

At the age of 6 something interesting happens. Because the demands of life get more and more complex for the child, the brain has to increase its efficiency. It goes about that using a process called 'pruning'. It's a bit like pruning a tree. How does the brain know what neuro connections to prune away? It goes by the traffic volume. If a connection is used frequently, lets say "being reassured", it will stay while the connection "it's unsafe to climb a tree because I fell down once" will be pruned away. The image I have in my mind is that of a path through the bush that is not used very often and starts growing over and over time becomes invisible.

For a person with lots of childhood stress (abuse, neglect, hardship) there may not be a lot of "I am OK" left after the pruning process. But not only that! There is another problem being added here: stress causes all sorts of neuro-physiological changes, for example more norephinephrine, dopamine, endogenous opioids, and gluccocoricoids and less serotonin, all hormones that interfere with - or even close down - adaptive mental processes. These hormones also disrupt cognitive and memory processes, leading to a break-down of an integrated sense of self and overall mental well-being.

Such collapse could manifest itself in incoherent narratives of past and present experiences, disturbances of identity and self-confidence, self-esteem, self-respect, fear, over-compliance, non-compliance, aggressiveness, or elusiveness.

While this may all seem very grim, here comes the ray of hope! The brain is able to constantly build new neuro pathways - even until we die. Of course, it's not as quick and easy as in childhood, but it does happen. Otherwise we wouldn't be able to learn a new language, learn a new skill, learn a new behaviour, or even change our mind. Otherwise there would be no need for therapists!