Definition and Prevalence

Insomnia is an experience of inadequate or poor quality sleep characterized by one or more of the following:

• difficulty falling asleep
• difficulty maintaining sleep
• waking up too early in the morning
• non-refreshing sleep

Insomnia can also involve daytime consequences such as

• tiredness
• lack of energy
• difficulty concentrating
• irritability

Periods of sleep difficulty lasting between one night and a few weeks are referred to as acute insomnia. Chronic insomnia refers to sleep difficulty at least three nights per week for one month or more. About 30 - 40 percent of adults indicate some level of insomnia within any given year, and about 10 to 15 percent indicate that the insomnia is chronic and/or severe. The prevalence of insomnia increases with age and is more common in women.