Predicting antipsychotic drug response - replication and extension to six weeks in an international olanzapine study

Schizophr Res. 2008 Apr;101(1-3):312-9. doi: 10.1016/j.schres.2008.01.018. Epub 2008 Mar 4.


Objective: To use the degree of response after 2 weeks of treatment to predict non-response at 4 to 6 weeks.

Method: Post-hoc re-analysis of a large multi-centered double-blind trial including 1996 patients with schizophrenia using receiver-operator curves and logistic regression analyses to predict non-response at 4 weeks and at 4-6 weeks from the percentage BPRS change at weeks 1 and 2. The primary non-response criterion was a less than 25% BPRS reduction from baseline.

Results: A 0% BPRS reduction at 2 weeks predicted non-response at 4 weeks with a positive predictive value of 77.1%; and sustained non-response at weeks 4, 5 and 6 with a positive predictive value of 75.8%. In a secondary last-observation-carried forward-analysis a less stringent cutoff of < or =15% BPRS reduction was associated with an acceptable positive predictive value (75%), with even higher sensitivity (76%).

Conclusions: Those patients who showed little to no reduction of symptoms at week 2 were unlikely to show even minimal response at weeks 4 to 6. There is increasing evidence that such patients may benefit from a change in treatment.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antipsychotic Agents / therapeutic use*
  • Benzodiazepines / therapeutic use*
  • Double-Blind Method
  • Follow-Up Studies
  • Haloperidol / therapeutic use*
  • Humans
  • International Cooperation*
  • Logistic Models
  • Olanzapine
  • Predictive Value of Tests
  • Psychiatric Status Rating Scales
  • ROC Curve
  • Schizophrenia / drug therapy*
  • Sensitivity and Specificity
  • Treatment Outcome


  • Antipsychotic Agents
  • Benzodiazepines
  • Haloperidol
  • Olanzapine