Rates and predictors of remission in first-episode schizophrenia within 1 year of antipsychotic maintenance treatment. Results of a randomized controlled trial within the German Research Network on Schizophrenia.

Objective: Full and sustained symptom remission is a major treatment objective after a first-episode in schizophrenia. Findings regarding differences in remission between first- and second-generation antipsychotics are inconclusive. This study aimed to provide rates and predictors of remission in first-episode schizophrenia and to identify symptoms that prevent remission.

Methods: Prevalence rates of "symptomatic remission" (symptom criteria only) and "enduring remission" (symptom and 6-month time criteria), defined according to Andreasen et al. (2005), were determined in first-episode patients participating in a RCT by the German Research Network on Schizophrenia (GRNS) that compared post-acute, 1-year maintenance treatment with risperidone or haloperidol. Respective predictors at baseline were identified by logistic and Cox regression analysis.

Results: Prevalence rates were 91.5% for symptomatic remission (n=152/166 eligible patients) and 58.6% for enduring remission (n=65 of 111 patients who continued for at least 6 months; 39.2% of all 166 patients included), with no significant differences between risperidone and haloperidol in either type of remission. Enduring remission often was not reached because of negative symptoms: After 6 months, 40.5% of the patients had at least 1 negative symptom, whereas only 10.8% of the patients had "persisting" positive symptoms. Of the different predictors identified in univariate analyses, (lower) negative symptoms and participating in standardized psychological treatment remained significant in multivariate (stepwise forward) analyses for enduring remission.

Conclusions: By far most of the first-episode patients reached a temporary state of full symptomatic remission within 1 year of antipsychotic treatment. However, only about 50% achieved sustained, enduring remission. Negative symptoms are still a major treatment obstacle to enduring remission in schizophrenia.