Monitoring the Prevalence of Depressive Symptoms and Related Factors in Japanese Employees: A Comparative Study between Surveys from 2007 and 2010

Aims: The aim of this study was to examine the prevalence of depressive symptoms and their related factors in Japan. Depressive disorder is one of the most common mental disorders and is a major public health problem in Japan. The results were analyzed to identify the relationship between high scores on the CES-D, socio-demographic status, and employment-related variables.

Methods: Employees in Akita prefecture completed the Center for Epidemiologic Studies Depression Scale (CES-D) during a survey period between November and December 2010. The cutoff point for the CES-D scores was 16 or above (high scorers).

Results: Data from 1,476 employees indicated that 44.2% had high scores on the CES-D. Socio-demographic and occupation-related factors associated with a high risk of depression were being female, young age, fewer hours of sleep on weekdays, and working over 8 hours per day, whereas drinking alcohol one to two days per week, albeit only in men, was significantly associated with a low risk of depression. The present results were consistent with the results of a previous survey completed in 2007; however, the present results regarding job categories and smoking behavior were not significantly associated with depression, and thus were inconsistent with the 2007 survey data.

Conclusions: The data presented in this paper will help identify employees at high risk of depressive disorders as well as detect the contributing socio-demographic and work-related factors. These results can be useful as benchmark values for the CES-D and might help predict depressive disorders.