Symptomatic and functional remission of subjects at clinical high risk for psychosis: a 2-year naturalistic observational study.

Background: The aim of this study was to assess the frequency and predictors of symptomatic and functional remission in individuals at clinical high risk (CHR) for psychosis at 1-2 years of follow-up.

Methods: Help-seeking CHR individuals with symptomatic (Scale of Prodromal Symptoms (SOPS) positive scores <3) and functional (Global Assessment of Functioning (GAF) score >60) (CHR-R) remission at 12-24 months were compared to non-remitted individuals (CHR-NR) regarding baseline and treatment characteristics, symptom changes and predictors. Time to full remission was compared with that of symptomatic remission only.

Results: Of 73 individuals, 29 (39.7%) achieved full remission; 44 (60.3%) did not. Compared to CHR-NR individuals, CHR-R individuals had lower baseline SOPS positive symptoms (p=0.017), antipsychotic use (p=0.004), antipsychotic chlorpromazine dose equivalents (p=0.001) and anxiolytic use (p=0.004). In survival analyses, the estimated full remission rate was 48.3% (95% confidence interval (CI)=36.2-61.9) and symptomatic remission rate was 67.5% (CI95=55.4-79.2). Time to full remission was longer than time to symptomatic remission (p=0.017). Linear mixed-effect models revealed significantly greater improvements from 6 months onward in CHR-R subjects compared to CHR-NR subjects regarding SOPS positive symptoms (p=0.003), highest SOPS positive symptom (p<0.001) and GAF scores (p=0.004). Examining baseline predictors, time to full remission was significantly longer in patients with higher SOPS positive scores (p=0.017).

Conclusions: More stringent remission criteria that include functional status in addition to attenuated positive symptom severity should be applied to CHR subjects. Furthermore, more attention should be given to CHR individuals with highly positive prodromal symptoms at baseline.