Remission in schizophrenia - What are we measuring? Comparing the consensus remission criteria to a CGI-based definition of remission and to remission in major depression.

Background: Despite being recommended for use in clinical trials, the consensus remission criteria were found to leave patients with persisting symptoms, relevant areas of functional impairment and a decreased sense of wellbeing. Therefore, to evaluate the appropriateness of the schizophrenia consensus criteria, a definition of remission based on the Clinical Global Impression Scale (CGI) was developed and remitter subgroups were compared.

Methods: 239 patients with a schizophrenia spectrum disorder were evaluated regarding their remission status after inpatient treatment. Remission in schizophrenia was defined according to the symptom-severity component of the consensus criteria by Andreasen et al. and a CGI based definition was calculated using sensitivity and specificity using receiver operating curves (asymptomatic remitter). Both remitter groups (schizophrenia consensus versus asymptomatic remitters) were compared regarding different clinical variables at discharge as well as the likelihood to relapse within a 1-year follow-up period. Both schizophrenia remitter subgroups were compared to remitters in major depression as a reference value.

Results: Following the consensus criteria, 63% of the schizophrenia patients were in remission compared to only 18% following the asymptomatic criterion. The schizophrenia consensus remitters were less likely to be concurrent treatment responders (p < 0.0001), had a significantly greater illness severity (p < 0.0001) and less functioning (p = 0.0358) as well as a significantly greater risk to relapse (p = 0.0174) compared to the schizophrenia asymptomatic remitters as well as the depressed remitters.

Conclusion: It should be critically re-evaluated if the currently proposed consensus criteria are adequate to measure what is traditionally understood to be remission.