title: Impact of dopamine supersensitivity psychosis in treatment-resistant schizophrenia: An analysis of multi-factors predicting long-term prognosis.
abstract: BACKGROUND
  Although a variety of factors are known to be significantly related to poor prognosis in schizophrenia, their interactions remain unclear. Dopamine supersensitivity psychosis (DSP) is a clinical concept related to long-term pharmacotherapy and could be one of the key factors contributing to the development of treatment-resistant schizophrenia (TRS). The present study aims to explore the effect of DSP on progression to TRS.
  
  
  METHODS
  Two-hundreds and sixty-five patients were classified into either a TRS or Non-TRS group based on retrospective survey and direct interview. The key factors related to prognosis, including the presence or absence of DSP episodes, were extracted, and each factor was compared between the two groups.
  
  
  RESULTS
  All parameters except for the duration of untreated psychosis (DUP) were significantly worse in the TRS group compared to the Non-TRS group. In particular, the TRS group presented with a significantly higher rate of DSP episodes than the Non-TRS group. Regression analysis supported the notion that DSP plays a pivotal role in the development of TRS. In addition, deficit syndrome was suggested to be a diagnostic subcategory of TRS.
  
  
  CONCLUSIONS
  Our data confirmed that the key predicting factors of poor prognosis which have been established would actually affect somehow the development of TRS. In addition, the occurrence of a DSP episode during pharmacotherapy was shown to promote treatment refractoriness.
authors.affiliation: Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan; Department of Psychiatry, Chiba Psychiatric Medical Center, 5 Toyosuna, Mihama-ku, Chiba 261-0024, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamanaka
authors.affiliation: Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan; Division of Medical Treatment and Rehabilitation, Chiba University Center for Forensic Mental Health, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan. Electronic address: kanahara@faculty.chiba-u.jp.
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Kanahara
authors.affiliation: Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan; Department of Psychiatry, Koutoku-kai Sato Hospital, 948-1 Kunugizuka, Nanyo City, Yamagata 999-2221, Japan.
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takase
authors.affiliation: Department of Psychiatry, Chiba Psychiatric Medical Center, 5 Toyosuna, Mihama-ku, Chiba 261-0024, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Moriyama
authors.affiliation: Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan; Division of Medical Treatment and Rehabilitation, Chiba University Center for Forensic Mental Health, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Psychiatry, Chiba Psychiatric Medical Center, 5 Toyosuna, Mihama-ku, Chiba 261-0024, Japan.
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Hirata
authors.affiliation: Department of Psychiatry, Chiba Psychiatric Medical Center, 5 Toyosuna, Mihama-ku, Chiba 261-0024, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Asano
authors.affiliation: Department of Psychiatry, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan.
authors.forename: Masaomi
authors.initials: M
authors.lastname: Iyo
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D004298:Dopamine / Q000378:metabolism*; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011605:Psychoses, Substance-Induced / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D012044:Regression Analysis; D012189:Retrospective Studies; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D004298:Dopamine
keywords: Antipsychotic; Deficit syndrome; Relapse; Tardive dyskinesia; Treatment-resistant