The mental illness microaggressions scale-perpetrator version (MIMS-P): Reliability and validity.

The study objective was to develop a new measure for use in the empirical measurement of microaggression behaviors perpetrated towards persons with mental illness and examine its psychometric properties. Following development of an initial item pool, 505 participants (students at a large college in New York City and community members recruited through Amazon's Mechanical Turk program) completed an online survey including a 20-item measure of microaggression behaviors. Exploratory factor analysis revealed three subscales: Assumption of Inferiority (α=0.81), Patronization (α=0.78), and Fear of Mental Illness (α=0.63). Additional analyses supported convergent validity of the measure with two widely used measures of mental illness stigma. The MIMS-P is the first instrument to measure microaggressions endorsed by perpetrators against a socially marginalized group and demonstrates strong psychometric properties. Inclusion of this scale in future research can help facilitate understanding of perpetrator perspectives and assist with intervention development.