title: Comparison of psychotic bipolar disorder, schizoaffective disorder, and schizophrenia: an international, multisite study.
abstract: OBJECTIVE
  Nosological distinctions among schizoaffective disorder (SA), bipolar I disorder with psychotic features (BDp), and schizophrenia (SZ) remain unresolved.
  
  
  METHODS
  We compared 2269 subjects with psychotic features in DSM-IV-TR diagnoses (1435 BDp, 463 SZ, 371 SA) from 8 collaborating international sites, by 12 sociodemographic and clinical measures, all between diagnostic pairs.
  
  
  RESULTS
  In bivariate comparisons, SA was consistently intermediate between BDp and SZ for 11/12 features (except onset stressors), and SZ vs. BDp differed in all 12 factors. SA differed from both BDp and SZ in 9/12 factors: SA and BDp were similar in education and suicidal ideation or acts; SA and SZ were similar in education, onset stressors, and substance abuse. Meta-analytic comparisons of diagnostic pairs for 10 categorical factors indicated similar differences of SA from both SZ and BDp. Multivariate modeling indicated significantly independent differences between BDp and SZ (8 factors), SA vs. SZ (5), and BDp vs. SA (3). Measurement variance was similar for all diagnoses.
  
  
  CONCLUSIONS
  SA was consistently intermediate between BDp and SZ. The three diagnostic groups ranked: BDp > SA > SZ related to lesser morbidity or disability. The findings are not consistent with a dyadic Kraepelinian categorization, although the considerable overlap among the three DSM-IV diagnostic groups indicates uncertain boundaries if they represent distinct disorders.
authors.affiliation: Department of Psychiatry, Harvard Medical School, International Consortium for Bipolar & Psychotic Disorder Research, Boston, MA, USA.|Lucio Bini Mood Disorder Center, Cagliari, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Tondo
authors.affiliation: Department of Psychiatry, Harvard Medical School, International Consortium for Bipolar & Psychotic Disorder Research, Boston, MA, USA.|Department of Neuroscience, Palermo University, Buenos Aires, Argentina.
authors.forename: G H
authors.initials: GH
authors.lastname: Vázquez
authors.affiliation: Department of Psychiatry, University of Köln, Köln, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Baethge
authors.affiliation: Viarnetto Psychiatric Clinic, Lugano, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Baronessa
authors.affiliation: Viarnetto Psychiatric Clinic, Lugano, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Bolzani
authors.affiliation: NeSMOS Department, Sant'Andrea Medical Center, University of Rome (Sapienza), Rome, Italy.|Lucio Bini Mood Disorder Center, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Koukopoulos
authors.affiliation: NeSMOS Department, Sant'Andrea Medical Center, University of Rome (Sapienza), Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Mazzarini
authors.affiliation: Bipolar Disorders Unit, Institute of Neuroscience, Hospital Clínic, University of Barcelona, IDIBAPS, CIBERSAM, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Murru
authors.affiliation: Bipolar Disorders Unit, Institute of Neuroscience, Hospital Clínic, University of Barcelona, IDIBAPS, CIBERSAM, Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Pacchiarotti
authors.affiliation: Lucio Bini Mood Disorder Center, Cagliari, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Pinna
authors.affiliation: Department of Psychiatry, Harvard Medical School, International Consortium for Bipolar & Psychotic Disorder Research, Boston, MA, USA.|Section of Psychiatry, Department of Neuroscience, University of Parma, Parma, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Salvatore
authors.affiliation: NeSMOS Department, Sant'Andrea Medical Center, University of Rome (Sapienza), Rome, Italy.|Lucio Bini Mood Disorder Center, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Sani
authors.affiliation: Viarnetto Psychiatric Clinic, Lugano, Switzerland.
authors.forename: V
authors.initials: V
authors.lastname: Selle
authors.affiliation: Neuropsychiatry Laboratory, Department of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy.|Beth K. and Stuart C. Yudofsky Division of Neuropsychiatry, Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, USA.
authors.forename: G
authors.initials: G
authors.lastname: Spalletta
authors.affiliation: NeSMOS Department, Sant'Andrea Medical Center, University of Rome (Sapienza), Rome, Italy.|Lucio Bini Mood Disorder Center, Rome, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Girardi
authors.affiliation: Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA.
authors.forename: M
authors.initials: M
authors.lastname: Tohen
authors.affiliation: Bipolar Disorders Unit, Institute of Neuroscience, Hospital Clínic, University of Barcelona, IDIBAPS, CIBERSAM, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Vieta
authors.affiliation: Department of Psychiatry, Harvard Medical School, International Consortium for Bipolar & Psychotic Disorder Research, Boston, MA, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Baldessarini
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000523:psychology*; D003710:Demography; D005192:Family Health; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011618:Psychotic Disorders / Q000523:psychology*; D012559:Schizophrenia / Q000175:diagnosis*; D066252:Sociological Factors
keywords: bipolar disorder; comparisons; psychosis; schizoaffective; schizophrenia