Most adults in the UK have experienced stress at least once in their lifetime, and it is a constant topic of conversation. But what is stress exactly? Why are some people more susceptible to stress than others? Is stress simply a product of our environment, or does genetics play a role?
Run Forest, Run!
Although most of us view stress in a negative light, it has played an important role in our evolution. In response to stressful situations, our bodies and minds go into overdrive and get ready to make potentially life-saving decisions.
This short-term benefit has strongly been for through generations. However, for modern humans, the stress we face on a daily basis is rarely life-threatening. When we refer to stress, most of us think about chronic stress or anxiety. Why do we feel this way? Do we have any control over it?
When faced with a threatening situation, your body reacts with a surge in key hormones: cortisol and adrenaline . These two hormones mediate your stress response and are responsible for the burst of energy you feel at times of high stress. When you are under chronic stress, these hormones remain elevated, leading to a long list of unpleasant symptoms, including headaches, insomnia, irritability, and anxiety. Some people seem to be able to shrug off stressful situations much faster than others. Is our response to chronic stress a learned behaviour or is it genetically determined?
The genetics of stress
A large number of studies have been conducted on the genetics of stress. Unsurprisingly, many of the genes associated with stress response are involved in the production or regulation of key hormones such as dopamine and oxytocin. A well-studied genetic variant in the COMT gene, which is involved in the breakdown of dopamine, has been linked to variations in susceptibility to stress . The letter A at this position is associated with higher dopamine levels, and greater vulnerability to stress.
Another key hormone, oxytocin, is also important in stress response. Individuals with one or more 'G' at the position rs53576 in the OXTR gene (which encodes the oxytocin receptor) were found to be, on average, better at handling stressful situations .
What does this tell us?
The physiological and psychological response to stress is extremely complex and involves multiple hormonal reactions. Although some studies have shown our genes can influence stress responses, other factors, such as our environment or upbringing can play a significant role. As is the case with most complex behaviours, your genes are only one part of the story.