What could be learned from a decade with standardized remission criteria in schizophrenia spectrum disorders: An exploratory follow-up study.

A decade has passed since the standardized remission criteria of schizophrenia spectrum disorders-the Andreasen Criteria-were defined. Over 2000 studies have been published, but only a few describe symptomatic remission over time. In this prospective study we followed patients for 3 and 5years, respectively. The aim was to investigate how different symptoms affect the occurrence of remission and how the remission cut-off level affects remission sustainability. The participants were patients diagnosed with schizophrenia spectrum disorders (DSM-IV). First, the importance of each core symptom for remission was examined using the Positive and Negative Syndrome Scale (n=274). Second, we investigated which items affect patients to either go in and out of remission or never achieve remission (n=154). Third, we investigated how the sustainability of remission is affected by a cut-off set to 2 (minimal) and 3 (mild) points, respectively (n=154). All core symptoms affected the occurence of remission, to a higher or lesser extent. Delusions and Hallucinatory behavior contributed the strongest to fluctuation between remission and non-remission, while the contribution of Mannerism and posturing was very marginal. Negative symptoms were enhanced when remission was never achieved. Moreover, the study found that remission duration was significantly longer for the cut-off score 2 rather than 3. The study shows that, over time, remission criteria discriminate between being stable, unstable, or never in remission. Patients with only a minimal occurrence of symptom intensity exhibit a significantly longer remission duration compared to patients with mild symptom intensity, indicating that the treatment goal should be minimal symptom intensity.