title: Under-reporting bipolar disorder in large-scale epidemiologic studies.
abstract: BACKGROUND
  To investigate if the prevalence of bipolar disorder in epidemiologic studies is an underestimate, as suggested by clinical studies.
  
  
  METHODS
  We analyzed data from 8 countries that participated in the World Mental Health Survey Initiative (n=47,552). We identified 6.8% and 18.9% of the sample who we think were screened out inappropriately (SCI) from the euphoric and irritable bipolar sections respectively. We compared them to those who were allowed to continue the section (CONT, 2.6% of the sample for euphoric; 1.0% for irritable) and to the reference group (REF, 69.5% of the sample).
  
  
  RESULTS
  The SCI group had consistently higher rates of major depression (29.1% vs. 6.4%), earlier age of onset (24.3y vs. 32.4y), more suicide attempts (13.3% vs. 5.9%), and more episodes (4.2 vs. 2.7) than the REF for the euphoric group. Similar findings exist for the irritable group. Also, comorbidity with anxiety, disruptive behavior disorders and substance use were much higher than the REF.
  
  
  CONCLUSIONS
  As with all epidemiologic studies, recall bias cannot be ruled out.
  
  
  CONCLUSIONS
  The findings above suggest that a number of the SCI subjects belong to the bipolar group. A revision of instruments used in epidemiologic research will probably prove what clinical studies have been showing that bipolar disorder is more common than has been reported.
authors.affiliation: Institute for Development, Research, Advocacy and Applied Care (IDRAAC), Beirut, Lebanon; Department of Psychiatry and Clinical Psychology, Saint George Hospital University Medical Center, Balamand University, Faculty of Medicine, Beirut, Lebanon. Electronic address: egkaram@idraac.org.
authors.forename: Elie G
authors.initials: EG
authors.lastname: Karam
authors.affiliation: Department of Health Care Policy, Harvard Medical School, Boston, MA, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Sampson
authors.affiliation: Institute for Development, Research, Advocacy and Applied Care (IDRAAC), Beirut, Lebanon.
authors.forename: Lynn
authors.initials: L
authors.lastname: Itani
authors.affiliation: Institute of Psychiatry, University of Sao Paulo Medical School, São Paulo, Brazil.
authors.forename: Laura Helena
authors.initials: LH
authors.lastname: Andrade
authors.affiliation: Division of Epidemiological and Psychosocial Research, National Institute of Psychiatry (Mexico) and Metropolitan Autonomous University, Mexico City, Mexico.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Borges
authors.affiliation: Department of Health Care Policy, Harvard Medical School, Boston, MA, USA.
authors.forename: Wai Tat
authors.initials: WT
authors.lastname: Chiu
authors.affiliation: National School of Public Health, Management and Professional Development, Bucharest, Romania.
authors.forename: Silvia
authors.initials: S
authors.lastname: Florescu
authors.affiliation: Faculty of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Horiguchi
authors.affiliation: National Center of Public Health and Analyses, Department Mental Health, Sofia, Bulgaria.
authors.forename: Zahari
authors.initials: Z
authors.lastname: Zarkov
authors.affiliation: International Mood Center, University of California at San Diego, La Jolla, CA, USA.
authors.forename: Hagop
authors.initials: H
authors.lastname: Akiskal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000453:epidemiology*; D016021:Epidemiologic Studies; D005260:Female; D014943:Global Health; D006306:Health Surveys; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000295:instrumentation*; D008875:Middle Aged; D015995:Prevalence; D012107:Research Design / Q000592:standards*; D055815:Young Adult
keywords: Bipolar disorder; Composite International Diagnostic Interview; Diagnosis