What Does the PANSS Autism Severity Score (PAUSS) Really Measure in Patients With First Episode Psychosis? Critical...

The PANSS Autism Severity Score (PAUSS) has recently become a popular measure of autistic features in psychosis populations, but evidence on its longitudinal reliability and factor configuration is poor. The aims of this investigation were to examine psychometric characteristics of the PAUSS in young patients with First Episode Psychosis (FEP) treated in an early intervention service, with primary interest for its long-term stability across 2 years of follow-up and factor configuration.

All FEP participants completed the Positive And Negative Syndrome Scale (PANSS) and Autism Quotient (AQ) at baseline and across the follow-up. Statistical analysis mainly included Cronbach's α to examine internal consistency of the PAUSS, Cohen's k statistics and Spearman's ρ correlation coefficients for its longitudinal stability and convergent validity with AQ scores, and exploratory factor analysis to explore its dimensions' configuration.

301 FEP participants were recruited (170 with Schizophrenia Spectrum Disorder [SSD]). Cronbach's α value for the PAUSS was 0.806, but with unacceptable inter-item correlations for PANSS G5 and G15 items. K value for examining PAUSS convergent validity with AQ score was unacceptable (0.295), as well as ρ and k values to quantify long-term test-retest reliability (< 0.750 and < 0.600, respectively). No long-term stability of the PAUSS scores across the follow-up was also found using Wilcoxon's test for repeated measure. Our EFA found a 2-factor model in the FEP total sample and a 3-factor configuration in the SSD subgroup.

Our results suggest that the PAUSS does not represent a valid instrument to assess autistic features in FEP and SSD. Indeed, the it probably captures psychotic symptom severity rather than autistic features, especially reflecting negative symptom load.