Abstract
Objectives: Identification of early clinical markers that predict later treatment outcomes in first-episode psychosis is highly valuable. The present study was conducted to determine the best time at which to predict the late treatment response in first-episode psychosis patients treated with paliperidone ER, factors predicting early treatment responses (at weeks 2 and 3) and the relationships between paliperidone ER plasma concentrations at weeks 2 and 3, and treatment responses at weeks 2, 3, and 8.
Methods: Various criteria for treatment response were employed. Plasma paliperidone concentrations at week 2 and 3 were determined using validated high-performance liquid chromatography/tandem mass spectrometry (LC-MS/MS). Treatment response at week 3 optimally predicted the later (week 8) response in terms of negative predictive value (NPV). Independent predictors for good treatment responses at weeks 2 and 3 were female gender, a higher educational level, a higher PANSS-excited score, and/or a shorter DUP.
Results: The plasma paliperidone concentration at week 3, but not week 2, was a significant predictor of the late treatment response (week 8).
Conclusion: These results may help appropriate clinical decision-making for early non-responders in first-episode psychosis.