Validation of the Brief Solastalgia Scale ( BSS ‐Br): Psychometric evidence of environmental distress in the Brazilian population

Abstract Background/Objective Environmental degradation increasingly drives psychological distress, yet no validated Portuguese‐language instrument exists to measure solastalgia, place‐based distress caused by environmental change. This study aimed to translate, culturally adapt and psychometrically validate the Brief Solastalgia Scale for Brazil (BSS‐Br). Methods The study was conducted in two phases. Phase 1 involved forward–backward translation, expert review, and cognitive debriefing ( n = 12) to ensure semantic and conceptual equivalence. Phase 2 comprised psychometric validation in a large cross‐sectional online sample ( N = 1752 Brazilian adults). Exploratory and confirmatory factor analyses (EFA/CFA), item response theory (IRT) modelling using a Graded Response Model, measurement invariance testing via multigroup CFA and convergent validity analyses were performed. Results Parallel analysis and EFA/CFA confirmed a unidimensional structure with good internal consistency (α = .77, ω = .78) and strong factor loadings (.57–.77). IRT modelling indicated high item discrimination (a = 1.23–2.29) and well‐ordered response thresholds. Scalar measurement invariance held across age, geographic region, education, parental status, living arrangement and exposure to environmental change. BSS‐Br scores correlated positively with depressive (PHQ‐9) and anxiety (GAD‐7) symptoms and negatively with well‐being (WHO‐5), supporting convergent validity. Conclusions The BSS‐Br is a reliable, valid and culturally appropriate measure of environmental distress for the Brazilian population. As the first validated solastalgia instrument in Portuguese and in a major Global South country, it offers a robust tool for environmental health and eco‐affective research in regions undergoing rapid socio‐environmental transformation.