Insomnia usually refers to a subjective report of difficulty with sleep, such as difficulty falling asleep, difficulty staying asleep, unrefreshing sleep, poor sleep quality, and inability to sleep without sleeping pills. It could be a disorder in its own right or a symptom of various psychiatric, medical, and/or other sleep disorders. Insomnia is one of the most common health problems in the general population. It is estimated that approximately 30% of the adult population shows insomnia symptoms regardless of its frequency and severity. Approximately 9–15% report sleep difficulties as well as daytime consequences and 6% show diagnosable insomnia. Women, the elderly, and individuals with psychiatric disorders are the groups with the highest risk for insomnia. This article describes the definition, clinical presentation, diagnosis, and contributing factors of insomnia, as well as the main concerns in the evaluation and treatment of insomnia in clinical practice.
Encyclopedia of the Neurological Sciences (Second Edition), 705-707