Effect of shift work on mental state of factory workers.

This paper examines the effects of shift work on the mental state of factory workers. As an indicator of the workers' mental condition, the authors used a scoring system (referred to below as the 'depression tendency score') based on the SRQ-D investigative report. The depression tendency score of the men was higher among the shift worker group than among the regular day worker group (p < 0.01). The depression tendency score of the male back-to-back shift workers was higher than that of the male regular day workers among skilled workers (p < 0.05). Among the women, no notable difference in depression tendency score was observed between the regular day worker group and the shift worker group. However, the depression tendency score of the female two-shift workers was higher than that of the female regular day workers among skilled workers (p < 0.05). We conclude that the mental health of men is easily affected by back-to-back shift work and that of women is affected by two-shift work because of the difference in modern societal/home role between man and woman.