Longitudinal validation of the Occupational Depression Inventory in Japan

This paper presents the first longitudinal validation of the Occupational Depression Inventory (ODI). The research focussed on the Japanese version of the instrument and comprised two studies. Study 1 was cross-sectional (N = 1,540; 50.1% female); Study 2 involved a three-month follow-up (N = 716; 49.4% female). The ODI exhibited essential unidimensionality, scalability, total-score reliability, convergent validity, and discriminant validity. The instrument demonstrated full measurement invariance – from configural to strict – across sexes, age segments, and time points. In men, lack of job security and medication use at Time 1 were associated with occupational depression at Time 2. In women, work ability at Time 1 was protective against occupational depression at Time 2. In both sexes, occupational depression at baseline predicted greater emotional labour and impaired work ability at follow-up. Occupational depression was more stable in women than in men. These findings support the criterion validity of the ODI, including its predictive validity. Overall, the ODI displayed excellent psychometric and structural properties and appears well-suited for assessing and addressing job-related distress in Japan. Through its longitudinal design, this study marks a step towards mapping the nomological network of occupational depression.