Self-report measures of beliefs about emotions for adults: a systematic review of conceptual approaches and psychometric properties using PRISMA-COSMIN methodology.

Beliefs about emotions are a key transdiagnostic factor in emotion regulation and mental health, yet conceptualisations vary widely, reflected in diverse self-report measures. The conceptual ambiguity and conflation hinder progress in the field. This systematic review, conducted using COSMIN-PRISMA methodology, examined the theoretical underpinnings and psychometric properties of questionnaires assessing beliefs about emotions in adults. Searches across four databases and secondary sources identified 22,891 records, with 24 articles representing 11 distinct measures included. Measures differed in their theoretical origins and dimensional structures. Overall, the quality of measure development was poor, with limited involvement of professionals or target populations during concept elicitation and content validation. Evidence supported the reliability and structural validity of six measures; however, further research is needed, particularly on content validity and test-retest reliability, to increase confidence in their psychometric robustness. No measure can currently be recommended for clinical use without reservations. Further research is also needed to enhance the clinical applicability of existing questionnaires, improve understanding of the breadth of beliefs about emotions, and evaluate the measurement invariance of existing questionnaires and the cross-cultural applicability of their underlying theoretical frameworks.