The impact of delay in clozapine initiation on treatment outcomes in patients with treatment-resistant schizophrenia: A systematic review

Parita Shah, Yusuke Iwata, Eric Plitman, Eric E. Brown, Fernando Caravaggio, Julia Kim, Shinichiro Nakajima, Margaret Hahn, Gary Remington, Philip Gerretsen, Ariel Graff-Guerrero

Research output: Contribution to journalReview article

11 Citations (Scopus)

Abstract

Approximately one-third of patients with schizophrenia have treatment-resistant schizophrenia (TR-SCZ), which is a condition characterized by suboptimal response to antipsychotics other than clozapine. Importantly, treatment with clozapine—the only antipsychotic with an indication for TR-SCZ—is often delayed, which could contribute to negative outcomes. Given that the specific impact of delay in clozapine initiation is not well understood, we aimed to conduct a systematic search of the Ovid Medline® database to identify English language publications exploring the impact of delay in clozapine initiation on treatment outcomes in patients with TR-SCZ. Additionally, clinico-demographic factors associated with clozapine delay were examined. Our search identified four retrospective studies that showed an association between longer delay in clozapine initiation and poorer treatment outcomes, even after including covariates, such as age, sex, and duration of illness. In addition, we found six studies that showed an association between age and clozapine delay, but results with regard to other clinico-demographic variables were inconsistent. Overall, the available literature reveals a possible link between delay in clozapine use and poorer treatment outcomes in patients with TR-SCZ. However, given the relatively small number of studies on this clinically important topic, future research is warranted to draw more definitive conclusions.

Original languageEnglish
Pages (from-to)114-122
Number of pages9
JournalPsychiatry Research
Volume268
DOIs
Publication statusPublished - 2018 Oct 1

Keywords

  • Clozapine
  • Delay
  • Outcome
  • Psychosis
  • Response
  • Schizophrenia
  • Treatment-resistant

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry

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    Shah, P., Iwata, Y., Plitman, E., Brown, E. E., Caravaggio, F., Kim, J., Nakajima, S., Hahn, M., Remington, G., Gerretsen, P., & Graff-Guerrero, A. (2018). The impact of delay in clozapine initiation on treatment outcomes in patients with treatment-resistant schizophrenia: A systematic review. Psychiatry Research, 268, 114-122. https://doi.org/10.1016/j.psychres.2018.06.070