Prevalence and Perceived Health Associated with Insomnia Based on DSM-IV-TR; International Statistical Classification of Diseases and Related Health Problems, Tenth Revision; and Research Diagnostic Criteria/International Classification of Sleep Disorders, Second Edition Criteria: Results from the America Insomnia Survey Thomas Roth, Catherine Coulouvrat, Goeran Hajak, Matthew D. Lakoma, Nancy A. Sampson, Victoria Shahly, Alicia C. Shillington, Judith J. Stephenson, James K. Walsh, and Ronald C. Kessler Background: Although several diagnostic systems define insomnia, little is known about the implications of using one versus another of them. Methods: The America Insomnia Survey, an epidemiological survey of managed health care plan subscribers (n = 10,094), assessed insomnia with the Brief Insomnia Questionnaire, a clinically validated scale generating diagnoses according to DSM-IV-TR; Interna- tional Statistical Classification of Diseases, Tenth Revision (ICD-10); and Research Diagnostic Criteria/International Classification of Sleep Disorders, Second Edition (RDC/ICSD-2) criteria. Regression analysis examines associations of insomnia according to the different systems with summary 12-item Short-Form Health Survey scales of perceived health and health utility. Results: Insomnia prevalence estimates varied widely, from 22.1% for DSM-IV-TR to 3.9% for ICD-10 criteria. Although ICD insomnia was associated with significantly worse perceived health than DSM or RDC/ICSD insomnia, DSM-only cases also had significant decrements in perceived health. Because of its low prevalence, 66% of the population-level health disutility associated with overall insomnia and 84% of clinically relevant cases of overall insomnia were missed by ICD criteria. Conclusions: Insomnia is highly prevalent and associated with substantial decrements in perceived health. Although ICD criteria define a narrower and more severe subset of cases than DSM criteria, the fact that most health disutility associated with insomnia is missed by ICD criteria, while RDC/ICSD-only cases do not have significant decrements in perceived health, supports use of the broader DSM criteria. Key Words: Classification, diagnostic criteria, epidemiology, health-related quality of life, insomnia, prevalence A n estimated one third of adults in Western countries ex- perience weekly difficulties with sleep initiation, mainte- nance, or nonrestorative sleep (1–3). Substantial propor- tions of these people meet diagnostic criteria for insomnia according to the criteria of either the American Psychiatric Asso- ciation DSM-IV-TR (4), the World Health Organization Interna- tional Classification of Diseases, Tenth Edition (ICD-10) (5), or the American Academy of Sleep Medicine International Classification of Sleep Disorders, Second Edition (ICSD-2) (6). The ICSD-2 criteria are identical to the Research Diagnostic Criteria (RDC) for insom- nia (7), so we refer to these throughout the article as RDC/ICSD criteria. The DSM, ICD, and RDC/ICSD criteria differ greatly (8,9), ham- pering systematic comparisons and accumulation of research findings (7,10). Although all these systems require difficulties initiating or maintaining sleep or nonrestorative sleep in addi- tion to daytime distress or impairment for an insomnia diagno- sis, they differ in the severity and specificity of these criteria and in additional requirements, such as the ICD requirement of pre- occupation with sleeplessness and excessive concern over con- sequences and the RDC/ICSD requirement that sleep problems occur despite adequate opportunity/circumstances for sleep. Little is known about the implications of these differences for comparative prevalence or correlates of insomnia across sys- tems. Such information could be useful in informing future sys- tem revisions. This is especially relevant, as the DSM and ICD are both scheduled for revision. The current article presents data on comparative prevalence and correlates of hierarchy-free diagno- ses of insomnia across these systems using data collected in the America Insomnia Survey (AIS), a large epidemiological survey of subscribers to a US health plan. From the Sleep Disorders and Research Center (TR), Henry Ford Health System, Detroit, Michigan; Sanofi-Aventis (CC), Paris, France; Depart- ment of Psychiatry and Psychotherapy (GH), University of Regensburg, Regensburg, Germany; Department of Health Care Policy (MDL, NAS, VS, RCK), Harvard Medical School, Boston, Massachusetts; Epi-Q, Inc. (ACS), Oak Brook, Illinois; HealthCore, Inc. (JJS), Wilmington, Delaware; and Sleep Medicine and Research Center (JKW), St. Luke’s Hospital, St. Louis, Missouri. Address correspondence to Ronald C. Kessler, Ph.D., Harvard Medical School, Department of Health Care Policy, 180 Longwood Avenue, Bos- ton, MA 02115; E-mail: kessler@hcp.med.harvard.edu. Received May 28, 2010; revised Oct 18, 2010; accepted Oct 24, 2010. BIOL PSYCHIATRY 2011;69:592– 600 0006-3223/$36.00 doi:10.1016/j.biopsych.2010.10.023 © 2011 Society of Biological Psychiatry