This article has two main objectives. The first is to examine the extent of stress, negative mental health outcomes and variations in mood states experienced by shift workers (N = 100) and a control group of day workers (N = 100) employed in Feeder Balancing Daify Ramnagar Varanasi and Kanpur, Dugdth Utpadak Sahakari Sangh (brand name Parag Ltd. for both organisations). Second to find out the relative contribution of stress variables andmoodstates in the prediction of mental health outcomes separately fir both shift workers and a control group of day workers. Our overall findings concur with other studies and provide evidence that shift workers significantly experienced higher levels of job and life stress, higher indices of negative mental health outcomes (as measured by GHQ - 28) and variations in mood states as compared to day workers. The results of the present study established some significant relationships between stress and negative mental health outcomes among both shift and day group of workers. However, the magnitude of correlation coefficients is slightly higher in the day worker group. For both groups of workers significant positive correlations were found between all the dimensions of negative mental health and mood states of tense arousal anger, energetic arousal and general arousal. The findings of step-wise multiple regression analysis indicated that amount of life stress and role conflicts were the two major predictors of negative mental health outcomes among shift workers. The results of a similar analysis carried out on day workers indicated that in the prediction of mental health of day workers, job related stressors (role ambiguios role conflict androle overload) played a significant role. The findings further indicated that shift workers' mood states such as anger, tense arousal and hedonic tone were also significant predictors of mental health outcomes. In day group of workers, anger coupled with low level of energetic arousal influenced their mental health. It is interesting to note, however, that in both groups of workers anger was the strongest predictor of all indices of negative mental health outcomes. Thus, the present study adds additional support to the notion that shift and night shift work is a potent source of stress. Shift work is opposed to the human circadian system and this conflict creates multiple physiological psychological and psychosocial problems for shift workers.
