Sleep and Stress Part 2: From Stress to Insomnia
This is part 2 of a two-part article on stress and its relationship to insomnia. In part 1, I explain how stress can biologically disturb sleep.
But how exactly does stress cause insomnia for some people? It isn't as obvious as just creating tossing and turning because that in and of itself isn't insomnia.
Cortisol and the "fight or flight" response
Compared to people without insomnia, people with insomnia have persistently high nighttime levels of cortisol. Cortisol, if you recall, is a stress hormone involved in the "fight or flight" mechanism. High cortisol levels are essential when the conditions require it.
High levels help you to focus your mind, raise your blood pressure, and prepare you for the "fight" part of your "fight or flight" reactions. Sometimes we need these responses; however, having them at night when trying to sleep is not helpful!1
So, why doesn't the sleeping problem go away when the stress does? Or when we learn to manage that stress so that it's not bothering us in an obvious way at night? For many people, the sleeping problem goes on long after the original stressful situation.
Worrying about the effects of insomnia
Often, people may then become concerned about their sleep and the impact that sleep loss is having on their lives. They might worry about the effects on work, on family life, and relationships. They may spend time reading about all of the risks of insomnia. They might read that they aren't getting the "right" number of hours (which is mythological by the way). They may begin to worry they aren't "normal" and that they "lost the ability to sleep", and other things that add stress to the pile.
Often these worries come in the night after the rush of the day's activities has stopped, and they realise they are laying there not sleeping...again.
What is a conditioned response?
Let's take Linda from Part 1. Linda's problems resolved but she remained worried about her sleep being so poor. At a certain point, she found herself so tired and so surprised to get in bed and suddenly be wide awake. She was confused as to why, and for some people with this problem there is a possible explanation: "conditioning."
If it didn't happen with the original negative stressors (which it often does), over time, this rush of cortisol that Linda was experiencing may have become what we call a "conditioned response."
A "conditioned response" is a biological, emotional, and psychological reaction that is triggered by a specific context or event that we've experienced repeatedly over time.
When worrying becomes a conditioned response
Conditioned responses are universal and we experience them all day, every day. It's the body and mind's way of efficiently preparing for life experiences. We learn by association that when one thing happens, then another thing happens or follows it....so why not get ready for that thing when it's "obviously" coming?
A simple example is a famous experiment Pavlov did with his dogs. Dogs (and all animals) salivate when they prepare to eat to make chewing more effective. So Pavlov experimented by ringing a bell before feeding his hungry dogs. The dogs came to associate the bell with their dinner and would salivate when they heard the bell - even if dinner did not appear. Salivating became conditioned to the sound of the bell.
Spending time in bed, worrying, and experiencing a rush of cortisol creates a conditioned response too. The body starts to associate going to bed with "time to rush out the cortisol" and worrying about whatever stressors are happening - or even worrying about sleep. The "bell" is being in bed, and the conditioned response is the worry and the cortisol.
When stress is resolved, does the conditioned response remain?
So over time, we can become "conditioned" to experience a rush of stress hormones and experience certain patterns of negative thinking when we are in bed. Sometimes this can even create fear of going to bed or going to sleep.
In some ways, the concept of stress as a cause of sleep disturbances is "common sense" -- and also extremely common; it happens to nearly everyone at some point. But it's sometimes less clear why stress can sometimes create insomnia as a problem in and of itself. Often the original stress resolves itself, but the sleeping problems remain. Understanding this "conditioned response" can be part of teasing apart the answers to some people's experiences of insomnia.
Do you recognise any of this of "conditioning" as part of your sleeping troubles?
Do you go to bed at the same time every night?