Study Identifies Predictors of Treatment-Resistant Schizophrenia

Theresa Wimberley PhD student National Centre for Register-based Research School of Business and Social Sciences Aarhus University

Theresa Wimberley Interview with:
Theresa Wimberley
PhD student
National Centre for Register-based Research
School of Business and Social Sciences
Aarhus University What is the background for this study? What are the main findings?

Response: Approximately 30% of patients with schizophrenia suffer from treatment-resistant schizophrenia, i.e. they do not respond to first-line antipsychotic treatment. Identification of high-risk patients as early as possible is crucial in order to optimize treatment and improve prognosis. In a large population-based cohort of patients diagnosed with schizophrenia we found the following candidate predictors of treatment resistance:

  • younger age at diagnosis,
  • living in less urban areas,
  • paranoid schizophrenia subtype,
  • a history of psychiatric hospital admission,
  • personality disorder,
  • suicide attempt, and
  • psychotropic drug use.

    Additionally, as opposed to other studies using treatment-based proxies for treatment-resistant schizophrenia, this study not only considered clozapine users as treatment resistant. We extended the proxy definition to include patients eligible for clozapine, as clozapine is considered to be under-prescribed. We found similar results regardless of definition used. What should clinicians and patients take away from your report?

Response: The lack of sufficient treatment response for patients with schizophrenia may to some degree be predictable by the patients’ history regarding both clinical and sociodemographic factors. Still, this study does not provide a tool for direct use in clinical practice; rather it supports and extends the evidence base of predictors of treatment-resistant schizophrenia, contributing to the development of future clinical prediction models. What recommendations do you have for future research as a result of this study?

Response: As a result of this study, future research should consider including the identified candidate predictors in prediction models for treatment-resistant schizophrenia. In combination with the clinical and sociodemographic predictors, genetic data could be included as well. Furthermore, I would recommend that future studies on treatment-resistant schizophrenia consider both clozapine users and patients eligible for clozapine Is there anything else you would like to add?

Response: Before the study, we hypothesized that known risk factors for schizophrenia might also predict treatment resistance. This was the case for illness-related factors such as previous psychiatric admission and other psychiatric diagnoses. This was not, however, the case for any of the included patient-related factors. This indicates that treatment-resistant schizophrenia does not merely represent the more severe spectrum of schizophrenia, but might also represent a distinct subtype of schizophrenia.


Predictors of treatment resistance in patients with schizophrenia: a population-based cohort study

Wimberley, Theresa et al.

The Lancet Psychiatry , Volume 0 , Issue 0 , Published Online: 24 February 2016

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Theresa Wimberley (2016). Study Identifies Predictors of Treatment-Resistant Schizophrenia 

Last Updated on March 1, 2016 by Marie Benz MD FAAD