Background: Serious mental illness (SMI) is profoundly stigmatised, such that there is even an impact on relatives of people with SMI. Aims To develop and validate a scale to comprehensively measure self-stigma among first-degree relatives of individuals with SMI.
Method: We conducted group interviews focusing on self-stigma with first-degree relatives (n = 20) of people with SMI, from which 74 representative quotations were reframed as Likert-type items. Cognitive interviews with relatives (n = 11) identified 30 items for the Self-Stigma in Relatives of people with Mental Illness (SSRMI) scale. Relatives (n = 195) completed the scale twice, a month apart, together with four external correlate scales.
Results: The 30-item SSRMI was reliable, with scores stable over time. Its single-factor structure allowed generation of a 10-item version. Construct validity of 30- and 10-item versions was supported by expected relationships with external correlates.
Conclusions: Both versions of the SSRMI scale are valid and reliable instruments appropriate for use in clinical and research contexts. Declaration of interest None.