A novel approach to measuring response and remission in schizophrenia in clinical trials

Background Pharmaceutical companies conduct clinical trials to show the efficacy and safety of new medications for the treatment of schizophrenia. After the new medications are marketed, clinicians treating patients with schizophrenia discover that a considerable number of patients do not respond to these new medications. The goals of the review are to examine the methodology and design of recent antipsychotic clinical trials, identify common flaws, and propose guidelines to fix the flaws and improve the quality of future clinical trials of antipsychotic medications. Methods A review of recent antipsychotic clinical trials was conducted using a PubMed search. Ten recent trials published in the past four years were reviewed and their methods analyzed and critiqued. Results The authors identified six major methodological flaws that may explain the suboptimal response in many patients after a drug is approved. Most of the flaws are related to eligibility criteria, the misuse of the Positive and Negative Syndromes Scale (PANSS) and the lack of consensus on how to define remission, response and exacerbation in schizophrenia. Proposed guidelines for a more rigorous use of the PANSS are presented and recommendations are proposed for using uniform criteria for remission, response and exacerbation in schizophrenia. Conclusions The authors recommend using standardized diagnostic interviews to screen patients for eligibility criteria and using the PANSS according to the author's recommendations and the proposed guidelines. Uniform criteria to define remission, response and exacerbation are recommended for clinical trials examining the efficacy and safety of antipsychotic drugs in schizophrenia.