Examining the psychometrics of the Psychopathology Inventory for Mentally Retarded Adults-II for individuals with mild and moderate intellectual disabilities

With growing recognition of the occurrence of psychological disorders in individuals with intellectual disability (ID), researchers and clinicians alike have placed emphasis on developing measures to assess for psychopathologies in this population. Despite an increased interest in the topic, there is still a dearth of psychometrically robust measures available to assess for psychopathology in adults with mild and moderate ID. The purpose of this study was to examine the psychometric properties of a revised measure for psychopathology in individuals with mild and moderate ID, the Psychopathology Inventory for Mentally Retarded Adults - second edition (PIMRA-II). Internal consistency, inter-rater reliability, and test-retest reliability were investigated. Validity was studied via convergent validity by comparing the PIMRA-II to the Assessment of Dual Diagnosis (ADD) and via discriminate validity by comparing the PIMRA-II to the Social Performance Survey Schedule (SPSS) prosocial scores. Lastly, an exploratory factor analysis was conducted to determine the factor structure of the scale.