title: Diagnostic Stability of ICD/DSM First Episode Psychosis Diagnoses: Meta-analysis.
abstract: Validity of current International Classification of Disease/Diagnostic and Statistical Manual of Mental Disorders (ICD/DSM) first episode psychosis diagnoses is essential in clinical practice, research, training and public health.
  
  
  
  We provide a meta-analytical estimate of prospective diagnostic stability and instability in ICD-10 or DSM-IV first episode diagnoses of functional psychoses. Independent extraction by multiple observers. Random effect meta-analysis conducted with the "metaprop," "metaninf," "metafunnel," "metabias," and "metareg" packages of STATA13.1. Moderators were tested with meta-regression analyses. Heterogeneity was assessed with the I2index. Sensitivity analyses tested robustness of results. Publication biases were assessed with funnel plots and Egger's test.
  
  
  
  42 studies and 45 samples were included, for a total of 14 484 first episode patients and an average follow-up of 4.5 years. Prospective diagnostic stability ranked: schizophrenia 0.90 (95% CI 0.85-0.95), affective spectrum psychoses 0.84 (95% CI 0.79-0.89), schizoaffective disorder 0.72 (95% CI 0.61-0.73), substance-induced psychotic disorder 0.66 (95% CI 0.51-0.81), delusional disorder 0.59 (95% CI 0.47-0.71), acute and transient psychotic disorder/brief psychotic disorder 0.56 (95% CI 0.62-0.60), psychosis not otherwise specified 0.36 (95% CI 0.27-0.45, schizophreniform disorder 0.29 (95% CI 0.22-0.38). Diagnostic stability within schizophrenia spectrum psychoses was 0.93 (95% CI 0.89-0.97); changes to affective spectrum psychoses were 0.05 (95% CI 0.01-0.08). About 0.10 (95% CI 0.05-0.15) of affective spectrum psychoses changed to schizophrenia spectrum psychosis. Across the other psychotic diagnoses there was high diagnostic instability, mostly to schizophrenia.
  
  
  
  There is meta-analytical evidence for high prospective diagnostic stability in schizophrenia spectrum and affective spectrum psychoses, with no significant ICD/DSM differences. These results may inform the development of new treatment guidelines for early psychosis and impact drug licensing from regulatory agencies.
authors.affiliation: Institute of Psychiatry Psychology Neuroscience, King's College London, London, UK.|OASIS Clinic, SLaM NHS Foundation Trust, London, UK.
authors.forename: Paolo
authors.initials: P
authors.lastname: Fusar-Poli
authors.affiliation: Institute of Psychiatry Psychology Neuroscience, King's College London, London, UK.|Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Cappucciati
authors.affiliation: Institute of Psychiatry Psychology Neuroscience, King's College London, London, UK.|Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Grazia
authors.initials: G
authors.lastname: Rutigliano
authors.affiliation: Institute of Psychiatry Psychology Neuroscience, King's College London, London, UK.
authors.forename: Margaret
authors.initials: M
authors.lastname: Heslin
authors.affiliation: Institute of Psychiatry Psychology Neuroscience, King's College London, London, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Stahl
authors.affiliation: Institute of Psychiatry Psychology Neuroscience, King's College London, London, UK.
authors.forename: Zera
authors.initials: Z
authors.lastname: Brittenden
authors.affiliation: Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy.
authors.forename: Edgardo
authors.initials: E
authors.lastname: Caverzasi
authors.affiliation: Institute of Psychiatry Psychology Neuroscience, King's College London, London, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: McGuire
authors.affiliation: Maryland Psychiatric Research Center, University of Maryland School of Medicine, and VA Capitol Network (VISN 5) MIRECC, Baltimore, MD.
authors.forename: William T
authors.initials: WT
authors.lastname: Carpenter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011618:Psychotic Disorders / Q000175:diagnosis*; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis*; D055815:Young Adult
keywords: DSM; ICD; diagnostic stability; psychosis; schizophrenia