The concurrent and predictive validity of symptomatic remission criteria in first-episode schizophrenia

Since the introduction of consensus criteria for symptomatic remission in 2005, most first-episode studies focused on cross-sectional relationship between remission status and functional outcome. Predictive validity of the proposed remission definition was under-studied. Relationship of remission with subjective quality of life (QoL) was inadequately addressed with inconsistent findings being observed.

One hundred and four Hong Kong Chinese aged 18 to 55years presenting with first-episode schizophrenia-spectrum disorder were studied. Socio-demographics, baseline clinical and functioning profiles were obtained. Psychopathological and functional reassessments were conducted at 6, 12 and 24months. Subjective QoL was measured at 12 and 24months. Symptomatic remission was operationally defined according to the consensus criteria developed by the Remission in Schizophrenia Working Group (RSWG), comprising both symptom-severity and 6-month duration components.

At 12months, 59.6% of patients achieved symptomatic remission. Remitted patients had significantly lower symptom severity, more favorable psychosocial functioning and better subjective QoL at 12months than non-remitted counterparts. Attainment of remission at 12months was significantly associated with fewer positive, negative, depressive and disorganization symptoms, higher levels of functioning and subjective QoL at 24months. Linear regression analysis indicated that remission status independently predicted functional outcome even when the effects of educational level, baseline functioning and negative symptom scores were controlled for.

The operationally defined symptomatic remission formulated by the RSWG represented a clinically valid construct that was found to be closely related to both concurrent and longitudinal outcomes on psychopathology, functioning and subjective QoL in the early stage of schizophrenia.