Psychometric Properties of the Japanese Brief State Rumination Inventory

Rumination is a repetitive thought pattern associated with depression and anxiety and has adverse effects. The Brief State Rumination Inventory (BSRI) is a self‐report measure of currently occurring state rumination, which better captures it. This study aimed to develop a Japanese version of the BSRI and examine its reliability and validity. In Study 1, a questionnaire survey was administered to 737 university students from two independent samples (Sample 1: 344; Sample 2: 367). The Japanese BSRI showed a two‐factor structure that best fit the data. The two factors were labeled “Introspection” and “Uncontrollable Negative Thoughts.” Additionally, the Japanese BSRI demonstrated adequate internal consistency and construct validity for trait rumination, mental health, mood, and mindfulness. In Study 2, we induced rumination and distraction and examined changes in the BSRI before and after induction. The results show that the Japanese BSRI is a reliable, valid, and useful scale for assessing state rumination.