Factors associated with depressive symptoms among workers employed in Japanese eldercare institutions: a cross-sectional study based on the Job Demand–Control–Support Model

We examined the association between depression symptoms and job stress based on the Demand–Control–Support model among workers employed in Japanese eldercare institutions. We randomly selected 197 eldercare institutions and invited workers to participate in a questionnaire survey. Depression symptom prevalence and severity were evaluated using the Center for Epidemiologic Studies Depression (CES-D) Scale (≥ 16 = high score). Job stress was assessed using the Job Content Questionnaire based on job Demand–Control–Support. A total of 2,727 workers agreed to participate. In total, 1,740 valid responses were obtained from 434 males and 1,306 females. Approximately 44.9% had high CES-D scores. Workers with long working hours had high and low scores of psychological job demand and social support, respectively. Those who exhibited high CES-D scores had significantly higher psychological job demand scores and lower decision latitude and social support scores. A positive correlation was found between psychological job demand and CES-D scores. By contrast, a negative correlation was found between decision latitude and CES-D scores and between the social support scores and CES-D scores. Employers and employees should be mindful of the risks associated with prolonged work hours to prevent depression. Moreover, special attention should be paid to workers with substantial psychological job demands, low decision latitude, and low social support, as these workers constitute a high-risk group.