Measurement invariance of the Self-Stigma of Mental Illness Scale (Short Form) across Scottish and Australian adults living with severe and enduring mental illness

People living with severe and enduring mental illnesses experience stigma and discrimination from multiple sources in society. Internalization of negative cultural messages about one’s experience of mental illness can lead to negative outcomes such as reduced self-esteem and help-seeking behaviors. Understanding whether these experiences differ across countries is important as efforts to tackle stigma are taking place internationally. This study estimates the measurement invariance of an adapted short form of a commonly used measure of internalized stigma, namely the Self-Stigma of Mental Illness Scale–Short Form (Corrigan et al., 2012), across Scotland and Australia. Data were collected, using two cross-sectional surveys, from adults living with severe, complex, and/or enduring mental health issue(s) in Scotland (N = 346; M _age = 39.80, SD _age = 13.74) and Australia (N = 1, 912; M _age = 39.21, SD _age = 12.82). Confirmatory factor analyses led to the Harm to Self-Esteem factor being removed from the Self-Stigma of Mental Illness Scale–Short Form. However, the resulting three-factor scale did not demonstrate measurement invariance across Scotland and Australia, raising questions about its use as a tool with which to conduct international comparisons.