Italian adaptation and evaluation of psychometric properties of the relaxation sensitivity index

In this work, we present the adaptation of the Relaxation Sensitivity Index (RSI) in the Italian context and evaluate its psychometric properties. RSI was developed under the anxiety sensitivity framework as an instrument to assess individual sensitivity (and subsequent fear) to the sensations related to relaxation. To test the original three-dimensional factorial structure proposed by Luberto et al. (2021), we conducted a confirmatory factor analysis (CFA) on a sample of 485 participants. Results confirmed the factorial structure also in the Italian context, demonstrating good internal consistency and convergent validity. Both the index at the general level and its single dimensions were positively associated with distress-related constructs (i.e., anxiety, depression, negative affect, worry, and boredom intolerance) and negatively with life satisfaction. Furthermore, we confirmed measurement invariance across gender, demonstrating the scale's broad applicability. By adapting this index to the Italian context, this study provides a new and valuable instrument for research and clinical applications, facilitating professionals and researchers in accounting for relaxation-related fears. The Italian version of the RSI thus contributes to understanding the mechanisms underlying anxiety associated with relaxation.