title: Impact of DSM-5 changes on the diagnosis and acute treatment of schizophrenia.
abstract: OBJECTIVE
  To examine the consequences and validity of changes in Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 diagnostic criteria for schizophrenia, eg, omission of subtypes, using a large dataset of double-blind, randomized, placebo-controlled schizophrenia trials.
  
  
  METHODS
  Data from 22 short-term efficacy registration trials of second generation antipsychotics for the treatment of acute psychotic episodes in patients with schizophrenia (N = 5233), submitted to the Dutch regulatory authority were analyzed. We examined whether patients in these pre-DSM-5 trials met the diagnostic criteria for schizophrenia according to DSM-5. Using linear regression, we examined differences in effect size between DSM-IV subtypes and between DSM-5 symptom dimensions.
  
  
  RESULTS
  Over 99.5% of the patients met DSM-5 diagnostic criteria for schizophrenia and no differences in effect size were found between schizophrenia subtypes (P = .65). Symptom dimensions that respond best to treatment with second generation antipsychotics were hallucinations, delusions, disorganized speech, and mania (Hedge's g -0.23 to -0.31).
  
  
  CONCLUSIONS
  Results of clinical trials in patients with pre-DSM-5 schizophrenia also apply to patients diagnosed with DSM-5 schizophrenia. Omission of the classic subtypes is justified as they are not predictive of response to treatment. The DSM-5 C-RDPSS scale adds valuable information to the categorical diagnosis of schizophrenia, which is relevant for antipsychotic response.
authors.affiliation: Medicines Evaluation Board, Utrecht, The Netherlands; tk.mattila@cbg-meb.nl.
authors.forename: Taina
authors.initials: T
authors.lastname: Mattila
authors.affiliation: Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Koeter
authors.affiliation: Medicines Evaluation Board, Utrecht, The Netherlands; Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Tamar
authors.initials: T
authors.lastname: Wohlfarth
authors.affiliation: Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jitschak
authors.initials: J
authors.lastname: Storosum
authors.affiliation: Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: van den Brink
authors.affiliation: Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Lieuwe
authors.initials: L
authors.lastname: de Haan
authors.affiliation: Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Eske
authors.initials: E
authors.lastname: Derks
authors.affiliation: Medicines Evaluation Board, Utrecht, The Netherlands;
authors.forename: Hubertus
authors.initials: H
authors.lastname: Leufkens
authors.affiliation: Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Damiaan
authors.initials: D
authors.lastname: Denys
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D017063:Outcome Assessment, Health Care; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000145:classification / Q000175:diagnosis* / Q000188:drug therapy*
chemical_list: D014150:Antipsychotic Agents
keywords: antipsychotics; clinical trials; diagnostic criteria