Why Can’t I Sleep? Should I Nap To Catch Up On Sleep?
When we feel stuck in a cycle of poor sleep and exhausted days, we often look for ways to ease our suffering. We might worry that not getting enough sleep at night is damaging our health, hurting our performance at work, or simply just feeling intolerable. When this happens, we might start looking to “catch up” on lost sleep by napping. If you are the kind of person who tries to catch up on lost sleep, naps, or tends to give themselves a lot of time to rest in bed, you might ask yourself “are there any downsides to this extra resting?”
One of the core models of sleep and insomnia on which cognitive behavior therapy for insomnia (CBT-I) is based is called the Two Process Model and was developed by Alexander Borbély in 1982. The Two Process Model posits that our sleep is regulated by our circadian rhythms (Process C) and by our sleep/wake homestat (the pressure we feel to fall asleep - Process S).
Process C usually functioning fairly normally in a person who struggles with chronic insomnia, though it is often a concern for people with what are called circadian rhythm sleep disorders (e.g., people who regularly cannot fall asleep until much later than is typical; or who feel extremely sleepy much earlier than is typical). Since we are thinking about insomnia and cognitive behavior therapy for insomnia in our case, it might be helpful to focus on how process S might be affected by rest and naps.
According to the Two Process Model, Process S reflects our drive for sleep and builds over the course of the time we are awake. As the day goes on and we remain awake, that drive increases until it and process C align such that we fall asleep. This is how it works in a person who is sleeping acceptably. When you have chronic insomnia, you might instead try to grab some sleep or rest whenever the opportunity presents itself. This is a coping strategy that makes complete sense in the short term, and it can work very well for a person suffering from jet lag or acute sleep deprivation or even acute insomnia.
Unfortunately, when it happens on an ongoing basis, your daytime naps and rest might inadvertently be regularly releasing the pressure that has built up for falling asleep at night. This means Process S is not very powerful when you are wanting to initiate sleep at night, and it can be misaligned with Process C, such that you might find yourself feeling tired but not actually sleepy.
A certain amount of that sleep drive needs to be present for you to fall asleep, and it takes quite a long period of wakefulness for it to reach that level. For better or for worse, even a relatively short nap can discharge enough pressure from process S to allow us to stay awake for a long time following that nap. Perhaps this was essential to our survival as a species when we had to live among predators and relied on short bursts of sleep, but it is not so helpful to those of us who struggle with chronic insomnia.
Think about whether this might apply to you. If it does, you might consider making some changes to your routine to keep that process S building up over the day to a nice healthy level.