Individual differences in the expansiveness of mental disorder concepts: development and validation of concept breadth scales

BACKGROUND: What people consider to be a mental disorder is likely to influence how they perceive others who are experiencing problems and whether they seek help for their own problems. However, no measure is available to assess individual differences in the expansiveness or breadth of concepts of mental disorder. Four studies aimed to develop and validate two such measures. The Concept Breadth-Vertical (CB-V) scale assesses variability in the severity threshold at which unusual behavior or experience is judged to reflect disorder, whereas the Concept Breadth-Horizontal (CB-H) scale assesses variability in the range of phenomena judged to be disorders. METHODS: In a pilot study (N = 201) for the CB-V, participants read vignettes of varying severity for each of the 10 mental disorders, and rated whether the subject had a disorder. Study 1 (N = 502) used exploratory factor analyses to examine 10 CB-V items from the pilot study and 20 vignette-based items for constructing the CB-H. Study 2 (N = 298) employed confirmatory factor analysis to validate the scales’ structure and examined their convergent validity with a measure of harm concept breadth and their discriminant validity with measures of mental health literacy. Study 3 (N = 298) explored associations of the scales with other mental health variables, including stigma and help-seeking attitudes. RESULTS: Study 1 supported the unifactorial structure of each item set, refined each set into a scale, and demonstrated acceptable reliabilities. Study 2 provided support for the scales’ convergent and discriminant validities. Study 3 showed that the scales were associated negatively with stigma, and positively with help-seeking attitudes and self-reported mental health problems. Studies 2 and 3 further indicated that younger and more politically liberal participants hold broader concepts of mental disorder. CONCLUSIONS: The new concept breadth scales are psychometrically sound measures of a promising new concept in the study of beliefs and attitudes about mental health. Potential future research directions are discussed. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-023-05152-6.