title: At risk for schizophrenic or affective psychoses? A meta-analysis of DSM/ICD diagnostic outcomes in individuals at high clinical risk.
abstract: BACKGROUND
  The clinical high-risk state for psychosis (HRP) is associated with an enhanced probability of developing a psychotic episode over a relatively short period of time. However, the extent to which different diagnostic types of illness develop remains unclear.
  
  
  METHODS
  A systematic review was performed to identify studies of HRP participants reporting International Classfication of Diseases/Diagnostic and Statistical Manual of Mental Disorders diagnostic outcomes at follow-up. Demographic, clinical, and methodological variables were extracted from each publication or obtained directly from its authors. A meta-analysis was performed of transition to schizophrenic (SP) or affective psychoses (AP) and to specific diagnostic categories. Statistical heterogeneity and small study bias were assessed, and meta-regressions were performed.
  
  
  RESULTS
  Twenty-three studies were retrieved, including a total of 2182 HRP participants, 560 (26%) of them developed a frank psychotic disorder over the follow-up time (mean = 2.35 y). Among HRP participants who developed psychosis, 73% were diagnosed with SP and only 11% with AP (Risk Ratio, RR = 5.43, 95% CI from 3.35 to 8.83). The specific transition risk to ICD/DSM schizophrenia was of 15.7% (over 2.35y). Heterogeneity was statistically significant and moderate in magnitude. Use of basic symptoms criteria in the baseline clinical assessment was associated with a further increase in the proportion progressing to SP vs AP (RR = 17.1). There was no evidence of publication bias and the sensitivity analysis confirmed robustness of the above results.
  
  
  CONCLUSIONS
  The HRP state is heterogeneous in term of longitudinal diagnoses; however, the current HRP diagnostic criteria appear strongly biased toward an identification of early phases of SP rather than AP.
authors.affiliation: Department of Psychosis Studies, Institute of Psychiatry, King's College London and OASIS team, South London and the Maudsley NHS Foundation Trust, London, UK. p.fusar@libero.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Fusar-Poli
authors.forename: Andreas
authors.initials: A
authors.lastname: Bechdolf
authors.forename: Matthew John
authors.initials: MJ
authors.lastname: Taylor
authors.forename: Ilaria
authors.initials: I
authors.lastname: Bonoldi
authors.forename: William T
authors.initials: WT
authors.lastname: Carpenter
authors.forename: Alison Ruth
authors.initials: AR
authors.lastname: Yung
authors.forename: Philip
authors.initials: P
authors.lastname: McGuire
mesh_terms: D000341:Affective Disorders, Psychotic / Q000453:epidemiology* / Q000523:psychology; D001714:Bipolar Disorder; D003865:Major Depressive Disorder / Q000453:epidemiology* / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D062706:Prodromal Symptoms; D011618:Psychotic Disorders / Q000453:epidemiology*; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology*