Sleep
Insomnia is a general term for difficulty falling asleep and/or staying asleep. Insomnia is the most common sleep problem, with many adults reporting occasional insomnia, and 10–15% reporting a chronic condition. Insomnia can have many different causes, including psychological stress, a poor sleep environment, an inconsistent sleep schedule, or excessive mental or physical stimulation in the hours before bedtime. Insomnia is often treated through behavioral changes like keeping a regular sleep schedule, avoiding stimulating or stressful activities before bedtime, and cutting down on stimulants such as caffeine. The sleep environment may be improved by installing heavy drapes to shut out all sunlight, and keeping computers, televisions and work materials out of the sleeping area.
Sleep inversion
Treatment of the delayed sleep phase type depends on the severity of the case. Mild cases may be addressed by an individual simply adhering to strict sleep and wake times. Severe cases may require incremental changes in sleep time, where a person sleeps 15 to 30 minutes earlier each day until an appropriate pattern is reached. Other methods of altering delayed sleep patterns include prescribing a night of sleep deprivation or the use of chronotherapy, a method in which sleep is delayed for three hours each night until the sleep pattern is rotated around the clock.