OBJECTIVES: The aim of this study was to examine the health-protecting effects of feeling useful to others on symptoms of depression and sleep disturbance in the workplace, as well as its buffering effects on associations between stressful work environments and symptoms of depression and sleep disturbance. METHODS: The subjects of this cross-sectional survey were 773 Japanese workers (response rate: 64.8%) of five organizations. Feelings of being useful to others were assessed with one simple question used in a previous study. Psychosocial work environment, sleep disturbance, and depressive symptoms were assessed using the Japanese versions of the Effort-Reward Imbalance Questionnaire, the Pittsburgh Sleep Quality Index, and the 28-item General Health Questionnaire, respectively. We tested for linear and interactive effects with hierarchical regression analyses. RESULTS: Feeling useful to others was significantly (p<0.05) and negatively associated with scores of depression and sleep disturbance both in the univariate analyses and after adjusting for age in both genders. Significant (p<0.05) interactions showed that, in both genders, as the effort-reward balance worsened, symptoms of depression increased, but feeling useful to others buffered the associations. CONCLUSIONS: The results support the notion that feeling useful to others in both genders in the workplace has possible health-protecting effects.
OBJECTIVES: The aim of this study was to examine the health-protecting effects of feeling useful to others on symptoms of depression and sleep disturbance in the workplace, as well as its buffering effects on associations between stressful work environments and symptoms of depression and sleep disturbance. METHODS: The subjects of this cross-sectional survey were 773 Japanese workers (response rate: 64.8%) of five organizations. Feelings of being useful to others were assessed with one simple question used in a previous study. Psychosocial work environment, sleep disturbance, and depressive symptoms were assessed using the Japanese versions of the Effort-Reward Imbalance Questionnaire, the Pittsburgh Sleep Quality Index, and the 28-item General Health Questionnaire, respectively. We tested for linear and interactive effects with hierarchical regression analyses. RESULTS: Feeling useful to others was significantly (p<0.05) and negatively associated with scores of depression and sleep disturbance both in the univariate analyses and after adjusting for age in both genders. Significant (p<0.05) interactions showed that, in both genders, as the effort-reward balance worsened, symptoms of depression increased, but feeling useful to others buffered the associations. CONCLUSIONS: The results support the notion that feeling useful to others in both genders in the workplace has possible health-protecting effects.