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 (alpha = .90, omega = .92), J-FMI presence (alpha = .80, omega = .80), and acceptance (alpha = .89, omega = .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.