Stress and Sleep
The vicious cycle
Stress and sleep are not very good friends. While there are many reasons for sleep problems in adults, psychological factors such as stress, anxiety, and worry play a significant role in causing and maintaining sleep impairments. Moreover, when you don't sleep well or enough, your personal resources for dealing with stress are significantly reduced. Even worse, chronic stress and sleep deprivation can dysregulate the physiological stress response, so that it doesn’t “turn off” when it should, making sleep even more difficult. So it becomes a downward spiral... Let’s take a closer look.
Stress and sleep: the physiological relationship
When we react to a stressful situation, the physiological stress response gets turned on. The levels of stress hormones (adrenaline, noradrenaline, cortisol) go up. The function of these hormones is to help mobilize energy in the situation of danger, to increase reactivity, to ensure alertness. Physiological processes that make us feel relaxed and sleepy are blocked (read more about stress physiology).
From an evolutionary point of view, this is a good adaptation: if you fall asleep when your survival is under threat, you will be dead very soon. Our ability to stay awake under stress can also be adaptive in modern times. For instance, it can help you pull off an all-nighter when you are preparing for an important exam. In a healthy person, the stress response is turned off when there is no more threat, and the hormones that make us alert return to their baseline level. However, when the stress becomes chronic, problems start to pop up. The state of stress is taxing, and the nervous system cannot withstand long periods of stress. The first thing that may break down is the stress response system itself. It becomes hypersensitive. We get agitated (nervous, anxious, irritated) about every little thing and we lose the ability to wind down, which is crucial for sleep. In other words, when we are constantly tense and stressed, the body loses its ability to relax and rest.
How sleep deprivation maintains the vicious cycle
Sleep is one of the best ways to restore the nervous system after a period of stress. On the contrary, sleep deprivation leads to a nervous system overload and only adds to the chronic stress. Here we have a vicious cycle: we don’t sleep enough, stress accumulates, the nervous systems gets dysregulated and becomes hyperactive and thereby only maintains the state of alertness.
To break this cycle, we can either ensure sufficient sleep (if we are able to sleep) or take a very close look at our life. We need to consider what causes stress, how to manage it, and most importantly, how to ensure sufficient downtime for the nervous system to heal itself.