What is Circadian Rhythm and how does it relate to your sleep?
This refers to your body’s internal clock. It exists in our brains, specifically in a group of cells called the suprachiasmatic nucleus (SCN). Like the smart center of your home, the circadian rhythm is responsible for coordinating many things. Circadian rhythm regulates your sleep and wakefulness, your body temperature, cortisol secretion along with many aspects of your physiology. In general, the stronger your circadian rhythm, the better quality sleep you will experience.
How do you strengthen your Circadian Rhythm (and your sleep)?
To strengthen your circadian rhythm, you need train it. Generally, it’s trained by keeping a consistent schedule day-to-day and through our exposure to light (both natural and artificial). So, it sounds like pretty simple thing then to improve your sleep: you just have to keep the same schedule. However, our world runs on 24-hour days, but our internal clock runs on 25-hour days! So, you also have to “wind up” your internal clock and manage the natural drift of a later and later sleep time. This is where Cognitive Behavioural Therapy for Insomnia is indicated. The use of sleeping pills is discouraged.
What is a CRSWD?
Circadian Rhythm Sleep-Wake Disorder occurs when there is a mismatch between your internal body clock and your environment’s clock. That is, if you need to go to work at 8 am, but that feels like 5 am for you, you may struggle with that. Your internal clock can either be delayed (relative to your environment) which would make you a “night owl”. Or, it can be early which would make you a “morning bird”. Or, it can be irregular. Irregular circadian rhythm usually involves sleeping in bursts of less than 4 hours at a time although you sleep your usual amount during a day.
How common are internal clock issues?
About 1.7% of the general population, and 5-10% of those suffering from chronic insomnia suffer from delayed sleep-wake phase disorder (DSWPD). This is highest in teenagers (about 7% of them) and it’s not because they are up gaming all night. About 1% of the population have the “early bird” variation of CRSWD (i.e., advanced sleep-wake phase disorder).
What causes internal clock issues?
We don’t really know although there are many theories like it happens naturally during teenage development; changes in amount of light exposure or sensitivity to light exposure, etc. People who have circadian rhythm sleep issues often also have depression and/or insomnia.
How do you know if an internal clock issue is affecting your sleep?
This is diagnosed with a thorough sleep history and through evaluating your sleep journal.
The key features in the history include:
1. Difficulty with falling asleep
2. Waking up too early
3. Not getting enough sleep and often feeling sleepy during the day
4. Decreased performance and happiness in life
Before starting CBT-i, we will have you keep a sleep journal. Our MD will then review this with you to help identify if there is a circadian rhythm issue.
How do you treat circadian rhythm sleep disorders?
CBT-i will focus on luring sleep into matching the schedule you need for your day-to-day life. Sometimes, some patients may benefit from some supplemental melatonin although you should only do this if instructed by a doctor. We are aware that melatonin is available over-the-counter, but there is a reason why in many European countries it’s only available by prescription.