What is stress?
Stress is a feeling that's created when we react to particular events - called stressors. It's the body's way of rising to a challenge and preparing to meet a difficult situation. The hypothalamus in the brain signals the adrenal glands to produce more of the hormones adrenaline and cortisol and release them into the bloodstream. These hormones speed up heart rate, breathing rate, blood pressure and metabolism. Blood vessels open wider to let more blood flow to large muscle groups, putting our muscles on alert. Pupils dilate to improve vision. The liver releases some of its stored glucose to increase the body's energy, and sweat is produced to cool the body. All of these physical changes prepare us to react quickly and effectively to handle the pressure of the moment.
Stress, or ‘the fight or flight response', is critical during emergency situations, but it can also be activated in a milder form at a time when the pressure is on but there's no actual danger - like that school exam or job interview. Of course, a little of this stress can help us rise to life's challenges. Also, the nervous system can quickly return to its normal state, standing by to respond again when needed. But, it's the abnormal levels that cause concern, and it seems that this is often set way back in early childhood.
Effects on childhood
When we think back on our lives we can all remember a time when we lost sleep worrying about a school exam, or later on when an important job interview was looming. But stress can reach even further back than that, exacerbated by poor quality of parenting.
The way we care for our children can affect the size of different sections of their brains in later life, and hence their behaviour patterns. Additionally, stressful parenting creates in the child abnormally high or low levels of the hormone cortisol. This is the chemical that prepares us for fight or flight against danger.
It is well-known that adult stress such as coping with a divorce or moving to a new neighbourhood can produce a lasting, low-level stress that's hard on people, but it can also have long-lasting effects on their children. The nervous system senses continued pressure and may remain slightly activated and continue to pump out extra stress hormones over an extended period. This can wear out the body's reserves, leave a person feeling depleted or overwhelmed, weaken the body's immune system, and cause other problems.
As children, if we have constantly felt in danger of attack or rejection, this produces low cortisol levels. In such children, when they become adult they become depressed or unresponsive to their surroundings. At its most extreme, there is such a state of flat emptiness that even if confronted by a murderer, there would be no marked reaction.
Conversely, if the childhood stress is more acute, with regular occasions of severe maltreatment or even complete abandonment, cortisol levels would be set high. As adults, that would make us hyper, with poor concentration and an inability to relax. Those with high cortisol levels are likely to be very sensitive, massively over-reacting to comparatively trivial events.
Whether too high or too low, abnormal cortisol levels in children damage growth of key regions of the brain and are associated with a host of psychiatric problems. Unfortunately, it is not just care provided in severely dysfunctional families that can cause abnormal levels, much commoner problems and practices can also have the same effect. There is widespread ignorance of this evidence, even among educated parents. Common problems in the early years such as parental depression or inadequate nursery care can cause abnormal cortisol levels. Although this may well worry parents, the upside is that you can significantly reverse the harm by changing the pattern of care. Even if the harm is already done and the child is in middle childhood, you can still achieve a great deal by giving the child extra love.
So, the good news is that in most cases, abnormal cortisol levels affecting stress can still be changed by subsequent experience.
It's never too late to care.
