The Positive and Negative Syndrome Scale for Schizophrenia Autism Severity Scale (PAUSS) in young people with autism and schizophrenia.

INTRODUCTION:Schizophrenia spectrum disorders (SSD) share symptoms with autism spectrum disorders (ASD). Autistic phenotypic profiles in SSD may be associated with a poor prognosis. We aimed to assess the evidences for reliability and convergent validity of the Positive and Negative Syndrome Scale for Schizophrenia (PANSS) Autism Severity Scale (PAUSS) in a sample of young people with ASD and SSD, and to use the PAUSS to explore correlates of "autistic profiles" in the SSD sample. MATERIALS AND METHODS:ASD (n=33, age=13-27 years) and SSD subjects (n=26, age=16-35 years) underwent PANSS, Autism Diagnostic Observation Schedule-Generic (ADOS-G), Autism Diagnostic Interview-Revised (ADI-R), and Social Responsiveness Scale (SRS) assessments. We derived PAUSS total/domain scores from the PANSS and applied these back-to-back with ADOS calibrated severity scores (CSS), ADI-R current behavior algorithm (CBA) scores, and SRS scores. RESULTS:Our results show evidence for an acceptable PAUSS score reliability and convergent validity both in the ASD and SSD samples. PAUSS total and socio-communication scores significantly correlated with ADOS Overall/Social Affect CSS, both in ASD and in SSD. SSD with higher PAUSS scores ("autistic-SSD") showed Overall/Social Affect CSS scores positioned in between ASD and "non-autistic SSD". The PAUSS total score was significantly associated with global functioning in SSD (adjusted R2=0.311). CONCLUSIONS:There seems to be evidence for the reliability and validity of PAUSS scores for quantifying autism symptom severity transdiagnostically and to identify "autistic phenotypes" in adolescents/young adults with SSD.