Lack of an inverse relationship between duration of untreated psychosis and cognitive function in first episode schizophrenia

Schizophr Res. 2009 Feb;107(2-3):262-6. doi: 10.1016/j.schres.2008.11.003. Epub 2008 Nov 29.


This study assessed the relationship between duration of untreated psychosis (DUP) and cognitive measures in order to assess if longer DUP was associated with worse performance. One hundred two patients with first episode schizophrenia or schizoaffective disorder were assessed on cognitive measures of speed of processing, episodic memory, executive function, and visual spatial processing at baseline (when patients were drug naive and after 16 weeks of olanzapine or risperidone treatment), so that a change score could be derived. DUP was defined by the emergence of psychiatric symptoms and the emergence of psychotic symptoms. Data were analyzed correlationally, parametrically (after the group was divided into long and short DUP by median split), and by regression. We found that DUP for psychotic symptoms in this group of patients was long, with a median of 46 weeks. Neither correlational, parametric analyses in which DUP served as a class variable, nor multiple regression indicated that longer DUP was associated with worse cognition at baseline or smaller magnitude of improvement in cognition. Our results suggest that while early intervention may be critical for symptom amelioration by shortening DUP, early intervention for treatment of psychiatric symptoms may have little or no impact on cognitive function. Furthermore, assuming that cognition is a core symptom of schizophrenia, the notion that ongoing psychosis is somehow toxic for a variety of information processing domains appears questionable.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Antipsychotic Agents / therapeutic use*
  • Benzodiazepines / therapeutic use*
  • Cognition Disorders / diagnosis
  • Cognition Disorders / drug therapy*
  • Cognition Disorders / psychology
  • Double-Blind Method
  • Early Diagnosis
  • Female
  • Humans
  • Male
  • Neuropsychological Tests / statistics & numerical data*
  • Olanzapine
  • Prognosis
  • Psychiatric Status Rating Scales
  • Psychometrics
  • Psychotic Disorders / diagnosis
  • Psychotic Disorders / drug therapy*
  • Psychotic Disorders / psychology
  • Risperidone / therapeutic use*
  • Schizophrenia / diagnosis
  • Schizophrenia / drug therapy*
  • Schizophrenic Psychology*
  • Young Adult


  • Antipsychotic Agents
  • Benzodiazepines
  • Risperidone
  • Olanzapine