Attaining and sustaining remission of predominant negative symptoms

Background: Evidence is lacking on remission in the presence of predominant negative symptoms. Aims: To examine remission rates and their variation by antipsychotic medication in predominant negative symptoms. Methods: Data were reanalyzed on patients (n = 383) who had participated in two double blind randomized placebo-controlled clinical trials of predominant negative symptoms lasting to 84 and 360. days. Symptom remission was defined with the Remission in Schizophrenia Working Group remission criteria of attaining and maintaining mild ratings on eight SANS items. Remission rates were examined to 90. days, survival analysis computed to ascertain time to attain symptom remission, binary logistic models used to predict the remission rate and 2 persistent months of symptom remission, and ANCOVA used to predict percent time in remission. Results: Symptomatic remission rates were: 22.72% at any visit during 90. days, and 3.66% lasting 2. months. Kaplan-Meier and Cox survival models to adjust for baseline symptom severity showed that compared with the placebo group the amisulpride group attained significantly (p < .05) more remission sooner (HR = 2.321, 95% CI = 1.36, to 3.97, p < .05). ANCOVA showed that compared with placebo the amisulpride group spent significantly (p < .05) more percent time in remission (ES = .28). Specificity analysis showed that: across trials the negative symptom remission rate was 25.1%; and in one 360-day trial the six-month remission criteria were attained and maintained by 6.4% of participants. Conclusions: Presented with predominant negative symptoms the Working Group Remission criteria appear not to be a pragmatic therapeutic objective. Modified remission symptom and time criteria may be an effective way to examine remission.