Discussion
schizophrenia, ill, SUD, psychosis
DISORDER
To investigate the optimum predictive cut-off value defining early non-response at week 2 and week 4 for schizophrenia patients using different atypical antipsychotics (olanzapine, risperidone, amisulpride, and aripiprazole) with different baseline severities of illness (severe, moderate and mild), we evaluated the prediction power under a series reduction of PANSS ranging from 0 to 20%. The main findings were as follows: first, in patients with schizophrenia treated with olanzapine, risperidone, amisulpride, or aripiprazole, those who show poorer early improvement after 2 weeks of antipsychotic treatment were less likely to respond later, and 4 weeks is sufficient to make a definitive determination of ultimate non-responders. Second, overall, the definition of early non-response that < 10% symptom reduction at week 2 and < 20% symptom reduction at week 4 had the best predictive value for non-response at week 8. Third, the optimum predictive cut-off value varies depending on the severity of the psychosis and the atypical antipsychotics being used.We investigated whether early non-response at week 2 and week 4 could be useful as a marker for assessing later non-response by performing a ROC analysis. The AUC in different subgroups were all ranging from 80 to 95%, indicating moderate diagnostic accuracy to high diagnostic accuracy [In addition, our study revealed that the optimal prediction thresholds varied with respect to different prediction time points. A < 10% symptom reduction at week 2 and a < 20% symptom reduction at week 4 (early non-response) had the best predictive value for non-response at week 8, which differs from a < 20% symptom reduction at week 2 and a < 30% symptom reduction at week 4 in patients treated with aripiprazole or quetiapine [The optimal cut-off values found in our research are inconsistent with a previous study, in which the optimal cut-off value was < 15% reduction in PANSS total score at week 2 and < 27% at week 4 for moderately-to-severely ill patients, < 12% reduction at week 2 and < 20% at week 4 in less than moderately ill patient group [Our study examined the effects of olanzapine, risperidone, amisulpride, and aripiprazole on patients with early schizophrenia over an 8-week period. We found that all three drugs were equally effective in improving symptoms in patients with severe schizophrenia, while aripiprazole was slightly less effective. In patients with mild schizophrenia, all four drugs showed similar effectiveness during the first 8 weeks of treatment. These results are consistent with previous research [The results of this study should be interpreted taking its limitations into consideration. This study included only four antipsychotics; therefore, further comparisons between drugs were unavailable. Moreover, the endpoint was set at week 8 which limits the prediction of long-term outcomes. Another limitation of our study is the absence of individual comorbidities, including substance use disorder (SUD), which are prevalent in this population. Lastly, we used the full 30-item PANSS to assess early response and non-response, which is a lengthy and unusual measure in clinical practice, potentially limiting the clinical applicability of the findings in real-world settings.