Development and Validation of the Japanese Version of the Impermanence Awareness and Acceptance Scale

Objectives This study aimed to develop and validate a Japanese version of the Impermanence Awareness and Acceptance Scale (IMAAS; Fernández-Campos et al., 2021) and examine its reliability, validity, and relationship with mental health. This 12-item scale consists of two factors: (1) impermanence awareness (IAW), the cognizance that all phenomena are transient, and (2) impermanence acceptance (IAC), the attitude of openness toward the transient nature of all phenomena. Methods Following a preliminary survey conducted with university students (N = 35), and exploratory factor analysis performed to improve the translation and eliminate unfit items, we conducted an online survey using a crowdsourcing service (N = 350). Confirmatory factor analysis (CFA), reliability and validity assessments, and correlation analyses with related scales were conducted. Results Notably, CFA confirmed the original two-factor structure; however, the model fit indices were low. Finally, a bifactor model was adopted, which improved the model fit (CFI = 0.97, TLI = 0.95, GFI = 0.96, RMSEA = 0.06, SRMR = 0.04). Correlation analyses revealed that the IMAAS demonstrated convergent validity with death acceptance, mindfulness, and well-being. Notably, IAC showed a strong negative correlation with fear of death ( r  = − 0.74, p  < 0.01) and a moderate positive correlation with well-being ( r  = 0.37, p  < 0.01). Conclusions The Japanese version of the IMAAS is proposed as a valid tool for measuring IAW and acceptance. Future research should further examine the cultural validity of this scale and explore extensively how IAW influences mental health and well-being in various cultural contexts.