What are Sleep Disorders?

Sleep disorders (or sleep-wake disorders) involve problems with the quality, timing, and amount of sleep, which result in daytime distress and impairment in functioning. Sleep-wake disorders often occur along with medical conditions or other mental health conditions, such as depression, anxiety, or cognitive disorders. There are several different types of sleep-wake disorders, of which insomnia is the most common. Other sleep-wake disorders include obstructive sleep apnea, parasomnias, narcolepsy, and restless leg syndrome.

Sleep difficulties are linked to both physical and emotional problems. Sleep problems can both contribute to or exacerbate mental health conditions and can be a symptom of other mental health conditions.

About one-third of adults report insomnia symptoms and 6-10 percent meet the criteria for insomnia disorder.1

Importance of Sleep

Sleep is a basic human need and is critical to both physical and mental health. There are two types of sleep that generally occur in a pattern of three-to-five cycles per night:

  • Rapid eye movement (REM) – when most dreaming occurs
  • Non-REM – has three phases, including the deepest sleep

When you sleep is also important. Your body typically works on a 24-hour cycle (circadian rhythm) that helps you know when to sleep.

How much sleep we need varies depending on age and varies from person to person. According to the National Sleep Foundation most adults need about seven to nine hours of restful sleep each night. The Foundation revised its sleep recommendations in 2015 based on a rigorous review of the scientific literature.

Many of us do not get enough sleep. Nearly 30 percent of adults get less than six hours of sleep each night and only about 30 percent of high school students get at least eight hours of sleep on an average school night.2 An estimated 35 percent of Americans report their sleep quality as “poor” or “only fair.”3

More than 50 million Americans have chronic sleep disorders.2