Attenuated first-rank symptoms and conversion to psychosis in a clinical high-risk cohort

We sought to examine attenuated first-rank symptoms (FRS) and subcomponents of the Unusual Thought Content (P.1.) section of the Structured Interview for Psychosis-Risk Syndromes (SIPS) to investigate the robust relationship between total P.1. and conversion. We hypothesized that attenuated FRS would drive the association and, additionally, be most predictive of a schizophrenia diagnosis.

We assessed 189 clinical high-risk participants. Two independent raters separately scored attenuated FRS and each subcomponent of P.1. as if each were the only symptom reported. Total P.1. was also scored. Participants were evaluated for conversion up to 2 years.

While total P.1. score significantly predicted conversion in the 54 converters, attenuated FRS, which were relatively uncommon in this sample, nor any subcomponent of P.1., was independently predictive. FRS did not predict conversion to schizophrenia among 35 subjects.

Although attenuated FRS, and subcomponents of P.1. of the SIPS, did not significantly predict transition to psychosis, our results support previous research affirming the value of total P.1. score as a tool for predicting conversion to psychosis.