Of the 43 CHR patients, 15 converted to a psychotic disorder within 2.5 years of study participation. Conversion to psychosis was defined by a rating of 6 on at least one of the positive symptom items from the SIPS, indicating the presence of a full-blown psychotic syndrome. A positive symptom is given a rating of 6 if it has reached a high intensity level (e.g., delusional conviction) and exceeds a frequency or duration threshold (≥1 hour/day for ≥4 days/week during the past month), or if it has a seriously disorganizing or dangerous impact on the patient (Cannon, 2008). Only CHR patients who were clinically followed for a minimum of twelve months (n=16) and had not yet converted to a psychotic disorder were included in the non-conversion group.
