New Study Highlights Effects of Sleep on Mood: The Importance of Uninterrupted Sleep
According to Ayurveda, sleep is one of the three pillars that—along with healthy lifestyle habits—can endow the body with strength, healthy complexion, and healthy growth for the span of a lifetime. The Ayurvedic texts also describe the maladies that can result from improper sleep including, but not limited to, misery, emaciation, weakness, stupor, fatigue, body aches and fever.
Proper sleep and rest are essential for the well-being of any individual. The body utilizes the sleep time to repair itself of any damage sustained during the waking hours. Good sleep also helps to maintain a healthy immune system and balance our appetites. A good night’s sleep enhances the same positive feelings and states of being that we achieve through our yoga practice. On the other hand, poor quality sleep:
1. Results in failure to sustain and preserve new memory
2. Triggers obesity and other metabolic disturbances
3. Contributes to accidents, falls and traffic mishaps
4. Triggers emotional disturbances
5. Lowers immunity, making the individual more susceptible to degenerative diseases or infections
Several recent studies have shown that lack of sleep or a discontinuous sleep during the night may be deleterious for the brain, and may trigger dementia and increase the risk of stroke symptoms. Unfortunately, we’re a world of unhealthy sleepers. If you compare the world statistics of insomnia and poor quality sleep, it is interesting to note that the numbers are nearly similar throughout the world. Within the United States, more than 30 percent of the population suffers from insomnia, with more than half of Americans failing to enjoy sound sleep due to tension, work, stress, and/or emotional upheaval. Between 40 percent and 60 percent of people over the age of 60 suffer from insomnia, with women up to twice as likely to suffer from insomnia than men. Nearly 10 million people in the U.S. use prescription sleep aids. Thus, the type of sleep and how we are affected by it is of great interest to sleep researchers.
In a recent study The Effects of Sleep Continuity Disruption on Positive Mood and Sleep Architecture in Healthy Adults, (1) researchers sought to find out which of two kinds of sleep is most likely to trigger poor health: the kind where you go to bed at the normal time but are constantly up every few hours (interrupted sleep), or the kind where you go to bed very late in the night and get a few hours of uninterrupted sleep (abbreviated sleep). In my personal opinion, while both kinds of sleep are unhealthy for the body and mind, people who wake up several times during the night, resulting in what is termed as interrupted sleep—even if they’re in bed for eight hours—are more unhealthy than people who sleep for very few hours of sleep that is uninterrupted sleep.
The study was conducted on a group of 62 healthy men and women who did not have any issues with sleep and were all good sleepers. The participants spent three days and nights in a sleep lab, with the researchers measuring and analyzing their sleep stages (light to deep slumber) with regard to how much of each stage of sleep each volunteer got every night.
The participants were randomly divided into three groups. The first group of 21 participants was awakened several times during the night (interrupted sleep), the second group of 17 was asked to go to sleep very late in the night, but their sleep was not interrupted (abbreviated sleep), and the third group of 24 serving as the control went to sleep early and was allowed to sleep uninterruptedly through the night. Participants answered questions about their moods (positive and negative) each evening before dozing off. The researchers also looked at the brain patterns of the individuals through a test called polysomnography.
When the researchers compared the mood of all three groups, the first two groups showed a decline in positive mood after the first night. But on the next two nights, the interrupted sleepers continued to report a significant decline in positive moods while the abbreviated sleepers did not report any further drop—their mood stayed at about the same level they had reported after the first night. The declining trend in the positive mood in the interrupted sleep group occurred regardless of what the participants reported on the negative mood scale. Thus, a disrupted sleep seems to have a stronger effect on dampening positive moods than it does on increasing negative emotions.
When the researchers looked at the brain patterns of the sleep groups, they found that the interrupted sleepers showed significantly less “slow-wave sleep” than the other two groups of sleepers that had slept continuously. (Slow-wave sleep, also known as deep sleep, is normally associated with feeling rested and rejuvenated.) The significant drop in the slow-wave sleep was associated with the striking drop in positive moods, having implications for how everything from stress to depression can affect both sleep and mood.
The most important question that is not yet answered by the study is whether interrupted sleep triggers faulty mood behavior or whether carrying negative moods to bed triggered interrupted sleep. Whatever may be the initiator, it appears that losing slow-wave sleep impairs the ability to recover or stabilize positive emotions. The researchers strongly advise that we need to pay attention not just to the quantity or quality of sleep, or the quantity or quality of mood/emotions, but to the combination of both sleep and moods.
Living in a hypercompetitive and stressful world with all the demands of work and family obligations, we need to at least lessen the negative impact on our lives of these demands by getting good quality, uninterrupted sleep. In addition to supporting the Ayurvedic concept of sleep being one of the pillars of life, this study appears to offer a reasonable explanation of why this is true.
For further reading on yoga, Ayurveda, and sleep, here are some articles you might find helpful:
Reprinted with permission from Yoga for Healthy Aging.
Ram Rao, Ph.D. With a doctorate in Neuroscience, Ram presently serves as a Research Associate Professor at the Buck Institute for Research on Aging. He focuses on various aspects of age-associated neurodegenerative diseases with emphasis on Alzheimer’s disease. In addition, Ram completed the academic training at the California College of Ayurveda (CCA) and received his certification as Clinical Ayurvedic Specialist. He has been a faculty of the California College of Ayurveda and teaches in their Nevada City location. Ram is also a dedicated Hatha yoga practitioner and is a Registered Yoga Teacher from Yoga Alliance USA. In his spare time, he offers consultations on YAMP techniques (Yoga, Ayurveda, Meditation & Pranayama). Ram has published several articles in major Yoga/Ayurveda magazines and has been a featured speaker at several national and international meetings and symposia. He is a member of the National Ayurvedic Medical Association (NAMA) and is on the Research Board of the Association of Ayurvedic Professionals of North America (AAPNA).