Authors' objectives:

The aim of this report was to conduct a systematic review of (1) the prevalence, natural history, incidence, risk factors and consequences of chronic insomnia in adults and (2) the efficacy and safety of treatments used in the management of chronic insomnia in adults.

Authors' results and conclusions: The interquartile range of prevalence of chronic insomnia varied from 8.5-24.3 percent across high quality studies of general populations, to 19.8-53.7 percent across moderate quality studies of outpatient populations, to 27.8-43.0 percent across moderate quality studies of clinical populations. Sleep onset latency (SOL) was significantly decreased by benzodiazepines (Mean Difference (MD): -16.5, 95% Confidence Interval (CI): [-20.5, -12.5]), nonbenzodiazepines (MD: -18.1, 95% CI: [-22.5, -13.7]), antidepressants (MD: -7.4, 95% CI: [-10.5, -4.4]) and melatonin (MD: -8.3, 95% CI: [-14.5, -2.0]). All of the preceding interventions, except melatonin, had a significantly higher risk of harm compared to placebo: benzodiazepines (Risk Difference [RD]: 0.15, 95% CI: [0.10, 0.20]), non-benzodiazepines (RD 0.05, 95% CI: [0.01, 0.09]), antidepressants (RD: 0.09, 95% CI: [0.01, 0.18]) and melatonin (RD: 0.09, 95% CI: [-0.11, 0.29]). Wakefulness after sleep onset (WASO) was not significantly reduced by melatonin (MD: -9.7, 95% CI: [-33.6, 14.3]). SOL was significantly decreased by relaxation therapy with short-term treatment (less than 4 weeks) (MD: -22.0, 95% CI: [-41.0, -2.9]); however, WASO was not significantly reduced by relaxation therapy (MD: -1.6, 95% CI: [-14.1, 10.8]). WASO was significantly decreased by cognitive/behavioral therapy (MD: -18.2, 95% CI: [-30.4, -6.0]); however, SOL was not significantly reduced by cognitive/behavioral therapy (MD: -4.6, 95% CI: -9.8, 0.6).

Authors' recommendations: There is evidence that chronic insomnia is associated with older age, female gender, present or past psychiatric illness and psychological problems, medical conditions and poor general health, increased healthcare utilization, lower quality of life and social relationships, socioeconomic status (marital separation, unemployment, poorer working conditions and lower social status), and decrements in memory, mood and cognitive function. There is evidence that benzodiazepines and non-benzodiazepines are effective in the management of chronic insomnia. There is some evidence that antidepressants are effective in the management of chronic insomnia: more research is required in this area. There is evidence that benzodiazepines, non-benzodiazepines and antidepressants pose a risk of harm. There is some evidence that melatonin is effective in the management of chronic insomnia in subsets of the chronic insomnia population, and there is no evidence that melatonin poses a risk of harm. However, more research is required in this area, given that the results are based on a small number of studies. There is evidence that relaxation therapy and cognitive/behavioral therapy are effective in the management of chronic insomnia in subsets of the chronic insomnia population. There is evidence that benzodiazepines have a greater risk of harm than nonbenzodiazepines.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.ahrq.gov/clinic/tp/insomntp.htm

Year Published: 2005

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)