- Restorative sleep is essential for overall physiological and mental functioning.
- The circadian rhythm, our internal clock, regulates our sleep-wake cycle and influences mood regulation.
- Disruptions to the circadian rhythm can lead to fatigue, irritability, and even depression.
by David Benitez, M.Sc., CBIS and Rita M. Rivera, M.Sc., CBIS, CTP.
Restorative sleep is a fundamental part of our daily routine, playing a valuable and biologically necessary role in maintaining our overall health and well-being. It is a sophisticated recurring state of rest that undoubtedly serves as the foundation for proper physiological and mental functioning. Despite its undeniable importance, many individuals struggle to get sufficient quality sleep. This post provides an overview of how circadian rhythms promote homeostasis and regulate mood while also discussing the unparalleled significance of sleep hygiene for those seeking to make a lasting change.
Restorative sleep is considered one of the primary pillars of wellness by The American College of Lifestyle Medicine (ACLM), along with proper nutrition, physical activity, stress management, avoidance of risky substances, and social connection. According to the ACLM (n.d.), improving sleep quality can enhance attention span and mood regulation. Let’s take a look at how sleep is related to mood.
Sleep and Circadian Rhythm
Our circadian rhythm is a natural biological process that modulates our sleep-wake cycle, among other things. It is an internal clock, operating 24 hours a day, influenced by external stimuli such as light and darkness. Thus, when our circadian rhythm is functioning correctly, we tend to feel alert and adequately energized during the day and in turn, tired and sleepy at night.
Still, disruptions to our circadian rhythm are likely to significantly impact our mood and, ultimately, overall well-being. For instance, jet lag, shift work, and prolonged exposure to artificial light at night can disrupt our circadian rhythm. In this scenario, the result is that it causes us to feel fatigued, irritable, and even depressed. Simply put, your circadian rhythm considerably influences your mood.
One of the primary ways circadian rhythm affects our mood is through melatonin regulation. Melatonin is a hormone produced by the pineal gland in the brain; it is responsible for regulating our sleep-wake cycle. As it begins to get dark, our brain releases more melatonin, which makes us feel sleepy and prepares us for sleep. On the other hand, as it gets light, our brain releases less melatonin, which makes us feel more alert and awake.
Another significant function of our circadian rhythm is the regulation of cortisol, a hormone involved in stress responses. Levels of cortisol naturally peak in the morning, which aids us in feeling alert and awake. Nevertheless, disruptions to our circadian rhythm can result in elevated cortisol levels at the wrong times, leading to or exacerbating feelings of anxiety, stress, and low or depressed mood.
Given the importance of our circadian rhythm in regulating our mood, it would be wise to implement adequate sleep hygiene to ensure that we get enough quality sleep. Sleep hygiene refers to the habits and practices we use to promote good sleep, such as maintaining a regular sleep schedule, creating a sleep-conducive environment, and avoiding activities that can interfere with sleep.
Sleep Hygiene Recommendations
Proper sleep hygiene encompasses a range of positive behavioral habits and environmental practices that effectively support healthy, restorative sleep. Some strategies to achieve effective sleep hygiene include:
- Establishing a regular sleep schedule. This involves setting consistent bedtimes and wake-up times, which help regulate our body's internal clock. The American Academy of Sleep Medicine (AASM, n.d.) suggests that adults should aim to get at least 7 hours of sleep every night to maintain good overall health. However, the amount of sleep needed varies among individuals and is influenced by factors such as genetics, behavior, medical conditions, and the environment.
- Avoiding harmful or risky substances before bedtime. This includes avoiding or limiting the consumption of caffeine, nicotine, and alcohol in the hours leading up to bedtime, as these substances can disrupt sleep and modifying the intake of certain medications not typically meant to be taken in the evening wherever possible—always consulting your prescribing health care provider based on individual circumstances.
- Creating a comfortable sleep environment. This involves setting the right temperature, lighting, and noise levels to ensure comfort to facilitate falling asleep and achieving quality sleep. You can make use of comfortable bedding and mattress, curtains that block out light, or earplugs for noise reduction and even utilize ambient or other sounds playing from a device if that is your preference. Maintaining a cool room also facilitates enhanced relaxation, thus helping improve your bedtime routine and overall sleep.
- Avoiding the use of electronic devices before bed. The blue light emitted by these devices may disrupt your circadian rhythm and make it harder for you to fall asleep. Research studies have shown that people who use their phones or computers in bed have a higher risk of insomnia compared to those who don't (Fuller et al., 2017; Shechter et al., 2018). To promote better sleep quality, try silencing or significantly decreasing the use of electronics at least an hour before going to bed and engaging in relaxing activities instead.
- Practicing relaxation techniques. You can try several techniques, such as meditation or deep breathing exercises. By engaging in these activities before bedtime, you can calm both your mind and body, reducing stress levels that may cause insomnia and other sleep disturbances.
Other recommended practices may include exercising regularly as well as avoiding large meals before bedtime.
The main objective of sleep hygiene is to help those striving to regulate their biological clocks to develop and maintain effective habits and behaviors that promote high-quality sleep, which positively impacts overall physical and mental well-being. It is important to highlight that individual differences in sleep needs, as well as preferences, may require fine-tuning in these practices in order to implement optimal sleep hygiene. Like most things in life, one size does not fit all. As such, you may want to try a few things to better identify what works for you. It is also important to assess your needs patiently and not by force; after all, you’re trying to go to sleep.
It is crucial to avoid activities that can interfere with our circadian rhythm and make it unnecessarily difficult for us to fall asleep and stay asleep. Restorative sleep is a vital component of our daily routines, which may be mistakenly seen as repetitive or unimportant but are, in fact, key components for sustainable, adaptive, and functional long-term well-being. Your daily routine, down to the small details you might not consider particularly noteworthy and perhaps even engage on autopilot, makes all the difference. Sleep plays a pivotal role in maintaining our overall biological homeostasis via the modulation of our circadian rhythm which is part and parcel of properly regulating our mood. By engaging in effective and individually-tailored sleep hygiene, we can help to ensure that our circadian rhythm is functioning correctly and that we are getting the restful and restorative sleep we need to feel our best and perform optimally throughout the day.
David Benitez, M.Sc., CBIS is a Doctor of Psychology in Clinical Psychology (Psy.D.) candidate with a concentration in Clinical Neuropsychology and a Certified Brain Injury Specialist (CBIS). Benitez is the Student Representative for the APA’s Society of Prescribing Psychology (Div. 55) and Vice-Chair of the American Academy of Clinical Psychology-Division of Graduate Students (AACP-DGS).
American Academy of Sleep Medicine. (n.d.). Sleep FAQs. https://sleepeducation.org/sleep-faqs/
American College of Lifestyle Medicine. (n.d.). What is lifestyle medicine? https://lifestylemedicine.org/
Fuller, C., Lehman, E., Hicks, S., & Novick, M. B. (2017). Bedtime Use of Technology and Associated Sleep Problems in Children. Global pediatric health, 4, 2333794X17736972. https://doi.org/10.1177/2333794X17736972
Shechter, A., Kim, E. W., St-Onge, M. P., & Westwood, A. J. (2018). Blocking nocturnal blue light for insomnia: A randomized controlled trial. Journal of psychiatric research, 96, 196–202. https://doi.org/10.1016/j.jpsychires.2017.10.015