An early improvement threshold to predict response and remission in first-episode schizophrenia.

Background: Early improvement with treatment is thought to be important in patients with first-episode schizophrenia, yet a valid definition is still outstanding.

Objective: To develop a valid definition of early improvement and test its predictive validity regarding response and remission.

Methods: We examined 188 in-patients with first-episode schizophrenia. Early improvement was defined as improvement in Positive and Negative Syndrome Scale (PANSS) total score at week 2, response as a 40% PANSS total score improvement at end-point, and remission according to consensus criteria.

Results: Reasonable predictive validity of early improvement was found for a 46% PANSS total score improvement at week 2 and a 50% improvement for remission (area under the curve: response 0.707, remission 0.692). Estimated confidence intervals ranged from 26 to 62% PANSS reduction for response and remission.

Conclusions: Patients with a first episode of schizophrenia should improve by at least 30% in PANSS total score at week 2 to achieve response and remission.