What role does stress play in mental illness?

Just chucking up what I wrote but forgot to actually publish in week 10… oops.

Stress plays a fundamental role in our functioning as human beings and in the development of society. It is defined as a normal physical response to threatening or upsetting events, which is generally considered an important part of our behaviour because it motivates us to meet deadlines and requirements, or to perform well under pressure. Further, the ‘stress response’ that we feel when our bodies believe that they are being threatened heightens our awareness and reactions, while also giving us extra energy to defend ourselves. That being said, excessive stress is unhealthy because it overwhelms us and thus negatively affects our ability to communicate, complete tasks and manage our lives properly.

This overwhelming kind of stress is a known contributor to mental illnesses such as extreme anxiety, depression, schizophrenia and post-traumatic stress disorder (PTSD). This is because while low amounts of stress (‘adequate’ acute stress, or stress that is not overwhelming) can improve productivity and motivation, excessive feelings of stress lead to irrational cognition and feelings of defeat and hopelessness. Furthermore, the pathophysiological significance of stress is huge because chronic stress disrupts various vital bodily systems. For example, it can raise blood pressure, suppress or increase appetite, contribute to infertility and speed up the aging process. Further, stress is a major contributor to unhealthy sleeping patterns that are commonly linked to mental illness. Most prominently amongst these is a condition called insomnia, which is the inability to fall or remain asleep for the desired amount of time, and is often linked to anxiety and depression.