Reliability and normative data of the Perceptual Aberration Scale in an Italian juvenile general population sample

Psychometric tools, such as the Perceptual Aberration Scale (PAS), have been developed to identify people at risk to develop psychosis. This paper aims at providing an Italian version of the Perceptual Aberration Scale and its normative data for the general juvenile Italian population. The Italian version of the PAS was produced using three independent translators. It was administered to 1089 non-clinical participants, stratified into three age-groups, i.e., 8-13, 14-17 and 18-24. The Italian version of the PAS displayed good internal consistency in each age-group evaluated (i.e. Alpha Coefficients: 0.90 for the 8-13 age-group, 0.84 for the 14-17 age-group, and 0.87 for the 18-24 age-group) and the assumption of unidimensionality was corraborate. Furthermore, normative data for the three groups were collected (i.e. cut-offs: 25 for the 8-13 age-group, 21 for the 14-17 age-group and 20 for the 18-24 age-group) and an age-related difference, as the 18-24 group scored lower than the younger groups, was found. The Italian version of the PAS proved to be a reliable psychometric tool to investigate perceptual aberration during childhood, adolescence and young adulthood.