A randomized, controlled study to examine the effect of group treatment for insomnia (CBT-I) in an outpatient clinic compared with waiting list and treatment-as-usual (sleep-hygiene based educational course)
Inclusion Criteria: * persons above the age of 18 * living in the municipalities of Oppegård and Ski * fits the criteria for moderate or severe clinical insomnia, as measured by Insomnia Severity Index (Bastien C. H., Valliéres A., Morin C. M., 2001) Exclusion Criteria: * bipolar disorder * epilepsy * severe depressive episode * psychosis disorders * somatic sleep disorders (untreated sleep apnea, restless leg syndrome, narcolepsy, and sleepwalking) * persons with a high risk of falling at home * persons handling heavy machinery * severe personality disorders