Development and Validation of the Japanese Version of the Freiburg Mindfulness Inventory-Short Form

Objectives: The 14-item Freiburg Mindfulness Inventory-short form assesses mindfulness, and enhanced mindfulness is beneficial for reducing anxiety and depressive symptoms. This study aims to develop a Japanese version of the measure (J-FMI) and examine its reliability and validity in a clinical population. Methods: Patients (N = 340) with mainly depression and/or anxiety completed the J-FMI and a set of questionnaires to measure the five facets of trait mindfulness, anxiety, and depressive symptoms after attending a 2.5-h mindfulness training program. Results: The exploratory factor analysis revealed that the J-FMI had two factors, with five items in the presence factor and nine in the acceptance factor. Internal consistency and reliability were high for the overall scale (α =.90, ω =.92), J-FMI presence (α =.80, ω =.80), and acceptance (α =.89, ω =.90) factors. In the correlation analyses, each J-FMI factor was significantly correlated with the five facets of trait mindfulness (r =.11 to.65) and anxiety and depressive symptoms (r = −.22 to −.61). There were no significant correlations between J-FMI presence and anxiety and depressive symptoms after acceptance was controlled (r = −.04 to −.05) in the partial correlation analyses. Conversely, significant correlations were noted between J-FMI acceptance and anxiety and depressive symptoms after presence was controlled (r = −.27 to −.53). Conclusions: These findings demonstrate the J-FMI’s high internal consistency, reliability, and factorial validity and support its criterion, convergent, and discriminant validity in a clinical sample, thus confirming its high reliability and validity.