The Natural History of Insomnia: the incidence of acute insomnia and subsequent progression to chronic insomnia or recovery in good sleeper subjects

The incidence rate of acute insomnia (3 or more nights a week for between 2 and 12 weeks) is remarkably high. This said, most incident cases resolve within a few days to weeks. Incident chronic insomnia only occurs in about 2 in 100 individuals.