Subcategories of the Clinical High-Risk State for Psychosis and Their Relationship to a Full First-Episode Psychosis Sample: An Exploratory Analysis of Longitudinal Outcomes.

Abstract

Background and hypothesis: Subcategories of the Clinical High-Risk state for psychosis (CHR-P) have been associated with differential risk for transition to first-episode psychosis (FEP), but their relevance for longer term FEP outcomes remains unclear. We aimed to determine the prevalence of 2 CHR-P subcategories - attenuated psychotic symptoms (APS) and brief intermittent psychotic symptoms (BIPS) - in a full sample of FEP patients, along with their association with outcome trajectories following psychosis onset.

Study design: Participants were recruited from an early intervention service and followed over 2 years, with repeated measures of psychotic symptoms, affective symptoms, and functioning. Pre-onset symptoms were assessed using follow-back methods to reconstruct subgroups and their prevalence within the sample. Linear mixed models were applied to examine associations between putative CHR-P subcategories and longitudinal outcomes.

Study results: Of 319 patients, 240 (75.24%) experienced subthreshold psychotic symptoms indicative of a CHR-P state; of these, 51 (21.25%) had potential BIPS (either alone or with APS) and 189 (78.75%) potential APS only. There were no mean differences in scores for psychotic symptoms, affective symptoms, or functioning between subgroups. However, there was a slower improvement in Global Assessment of Functioning (GAF) scores in the putative APS subgroup, which converged with the putative BIPS subgroup by year 2.

Conclusions: Putative CHR-P subcategories of APS and BIPS exhibited similar outcome trajectories beyond psychosis onset, except for a possibly slower functional recovery in the putative APS subgroup. Longer term studies across stages of illness are needed to better understand the prognostic utility of these identifiers after FEP.