Objective: To review published studies to assess the effects of supervisor training on the mental health of subordinate workers, and thereby develop an evidence-based guideline for supervisor training in promoting workers' mental health.
Method: Seven studies that assessed the effect of supervisor training, whose outcomes included psychological stress responses of (subordinate) employees, were retrieved for assessment from PubMed, the Cochrane Library, MEDLINE, the Web of Science, and Ichushi-Web. An additional five studies were also reviewed for discussion on the content and types of training.
Results: Providing supervisors with necessary skills and information on mental health, including relevant occupational stressors, has a favorable effect on workers' mental health, at least in the short term. The subject populations had a background of requiring mental health measures. The effect of the training varied depending on the participation rate of supervisors, suggesting that the overall effect on an organization may be limited without a certain extent of participation by supervisors. There is no evidence of a long-term (over 1 yr) effect of supervisor training, and the effect of education on the supervisors' knowledge and behavior tends to be lost after 6 mo.
Conclusion: The current evidence indicates that the following items should be taken into consideration for the development of a guideline for supervisor training: identification of high-priority populations requiring education, development of a strategy to improve the participation rate in education, inclusion of occupational stressors as well as basic information in workplace mental health teaching materials, and regular repetition of the program.