Intermittent or acute insomnia is common, and may sometimes require short-term treatment with an approved hypnotic agent.
A diagnosis of insomnia disorder, however, indicates that night-time sleep is of poor quality and chronic, and accompanied by
significant impairment of daytime functioning. Although insomnia disorder often co-exists with psychiatric and medical conditions,
it is viewed as an independent entity with potentially serious sequelae, requiring its own treatment, usually in the form of cognitive
behavioural therapy, with or without pharmacotherapy.