Mental health-related stigma is common and inhibits help-seeking. It triggers fears of devaluation and can add to the burden of a mental disorder. To counter the consequences of mental health-related stigma, its sound assessment is crucial. Therefore, we developed a new measure, the Stigma-9 Questionnaire (STIG-9), and evaluated its psychometric properties and applicability in patients with mental disorders. Item development was based on the modified labelling theory, psychometric reasoning, and discussion with focus groups including patients and clinicians. Data from 919 consecutive patients from an outpatient clinic for mental disorders (69% female, mean age 41 (SD = 14) years) was used to psychometrically evaluate the measure. The STIG-9 consists of nine items assessing cognitive, behavioural and affective aspects of perceived mental health-related stigma. Higher scores indicate stronger expectations of negative societal beliefs, feelings, and behaviours towards 'mentally ill' people. Confirmatory factor analysis revealed a single factor structure. The scale showed high internal consistency. Male gender, social impairment and higher levels of psychopathology corresponded with higher STIG-9 scores. The STIG-9 is a new, theory-grounded, patient-oriented and psychometrically promising self-report measure of perceived mental health-related stigma. It is brief, comprehensive, and appears to be well accepted by patients with mental disorders.
