Sleep is a vital aspect of a person’s physical and mental health and well-being. Fifty to 80 percent of patients with psychiatric conditions — including anxiety disorders, depression, attention deficit hyperactivity disorder (ADHD), substance abuse, bipolar disorder and schizophrenia — have chronic sleep problems compared to 10 to 18 percent of American adults in the general population. Although infrequent sleep difficulties are not too much of a concern, chronic sleep problems can have detrimental health consequences, lead to difficulty learning new things and concentrating, and affect protein synthesis in the hippocampus, an area of the brain that is important for memory.
Research indicates that sleeping fewer than the recommended seven to eight hours per night, having an irregular sleep schedule and getting poor quality sleep is associated with many health risks, including obesity, diabetes, high blood pressure, heart disease, stroke, anxiety and depression. Not only are people who do not get enough sleep more prone to waking up feeling groggy and distracted, drowsy driving impairs a person’s ability to drive safely. Lack of sleep compromises a driver’s alertness, attention, reaction time, judgment and decision-making, increasing the risk for getting into a car accident and contributes to up to 6,000 fatal car accidents each year.
How does the body regulate sleep?
A complete cycle of sleep takes an average of 90 minutes to complete. Sleep is divided into rapid eye movement (REM) sleep and four stages of non-REM sleep. Approximately 50 percent of total sleep time is spent in stage 2 sleep; about 20 percent is REM sleep and the other 30 percent is spent in the other stages. Each one of the sleep stages corresponds with different brain waves. Contrary to the common belief that our brains “shut off” during sleep, our brains are very active during sleep and have an important role for helping us feel restored, refreshed and prepared for the following day.
Most people will feel different levels of alertness and sleepiness at different times in the day. A person’s sleep-wake cycle is regulated in the body through sleep-wake homeostasis and circadian rhythms, which influence how awake or tired the person feels.
Circadian rhythms are responsible for regulating the body’s internal processes and alertness levels that are controlled by the body’s internal clock (i.e., the circadian clock), which is responsible for regulating circadian rhythms for sleep as well as other biological activities in the body — such as core body temperature, brain wave activity, cell regeneration and hormone production.
Sleep-wake homeostasis is another biochemical system in the body that tells us that we need sleep after we have been awake for a long period of time. Adenosine is an example of a sleep-regulating brain chemical that promotes sleep and suppresses arousal when it builds up in the body and makes us more tired. Sleep-wake homeostasis is an internal reminder to the body that it needs to sleep and functions like a timer — the longer we have been awake, the more pressure and stronger desire we feel to sleep. This sleep-wake homeostatic process plays a major role in non-REM sleep, regulates the circadian clock and directly affects alertness, performance and mood through light exposure.
The circadian clock is located in the suprachiasmatic nucleus (SCN) in the hypothalamus, which controls functions such as the sleep-wake cycle, body temperature, blood pressure and hormone secretion. The biological circadian clock is “set” primarily by visual cues of light and darkness that are detected by photoreceptors located in the retina and sent along the optic nerve to the SCN and then to several other brain areas. For example, the pineal gland receives light signals and switches off the production of melatonin.
What interferes with sleep?
More than 70 sleep disorders can impact a person’s ability to sleep — the most common sleep disorders are insomnia, narcolepsy, sleep apnea and restless legs syndrome. Researchers have estimated that about 50 to 70 million Americans have a sleep disorder that affects their ability to get a full night of sleep, and more than half of adults and nearly 70 percent of children have undiagnosed and/or untreated sleep problems.
Certain medications, drinking alcohol, smoking cigarettes and consuming caffeinated substances (e.g., coffee, diet pills and decongestants) can interfere with our ability to sleep, as they interfere with our normal sleep-wake cycle. That is why sleep problems are very common among people who use substances, such as nicotine and alcohol, which appear to help you relax and sleep but actually have the opposite effect (e.g., nicotine acts as a stimulant in the body).
The main categories of sleep disorders that affect people’s ability to sleep include the following:
Sleep disorders can lead to moodiness, fatigue, anxiety and stress, even among people without mental illness. Sleep disturbances can impair quality of life, contribute to relapse among individuals with psychiatric disorders and substance use problems, and can have adverse consequences on mood and our ability to deal with stress, noted Allison G. Harvey from the department of psychology at University of California, Berkeley.
Sleep problems such as insomnia are very common among people with mental illness and substance abuse, contributing to higher levels of stress, poor emotional and physical health, and relapse. The Sovereign Health Group recognizes the importance of sleep for patients in recovery and celebrates National Sleep Awareness Week this March 6-13, 2016. For more information about how the importance of sleep is incorporated into Sovereign Health’s comprehensive treatment programs for mental illness, substance abuse and co-occurring disorders, please contact our 24/7 helpline for further assistance.
About the author
Amanda Habermann is a writer for the Sovereign Health Group. A graduate of California Lutheran University, she received her M.S. in clinical psychology with an emphasis in psychiatric rehabilitation. She brings to the team her background in research, testing and assessment, diagnosis and recovery techniques. For more information and other inquiries about this article, contact the author at firstname.lastname@example.org.