Influencing factors and predictors of early improvement in the acute treatment of schizophrenia and schizophrenia spectrum disorder

Background: To examine the influencing factors and predictors of early improvement in schizophrenia patients.

Methods: 370 patients suffering from a schizophrenia spectrum disorder were examined within a naturalistic multicenter study. Early improvement was defined as a ≥30% PANSS total score reduction within the first two treatment weeks, response as a ≥50% improvement of the PANSS total score from admission to discharge and remission according to the consensus remission criteria. Baseline and course-related variables such as positive, negative and depressive symptoms, side effects, functioning and subjective well-being were examined regarding their explanatory value for early improvement.

Results: 46% of the patients were identified to be early improvers. Of these, 77% became treatment responder at discharge and 74% achieved the consensus remission criteria. Amongst others, early improvers were significantly more often first-episode patients (p = 0.009), with a significantly shorter duration of current episode (p = 0.024) and a shorter duration of the illness (p = 0.0094). A higher PANSS positive subscore (p = 0.0089), a higher score in the Strauss-Carpenter-Prognostic Scale (SCPS) (p < 0.0001), less extrapyramidal side effects (p = 0.0004) at admission and the development of less extrapyramidal side effects within the first two treatment weeks (p = 0.0013) as well as a duration of current episode of ≤6 months (p = 0.0373) were identified to be significant predictors of early improvement.

Conclusion: Early improvement is associated with less illness chronicity and seems to be independent of the type of antipsychotic and the antipsychotic dosage applied. The SCPS was found to be a valuable tool to detect early improvers already at the initiation of antipsychotic treatment.