Minor psychiatric disorders among nursing workers--is there an association with current or former night work?

We aimed at analyzing whether Minor Psychiatric Disorders (MPD) is associated to night work either currently or in the past. A cross-sectional study was conducted at three public hospitals in Brazil, with female nursing workers. Data collection (N=1,134) was based on a comprehensive questionnaire that included the self-reported questionnaire (SRQ-20) for screening of MPD. Former night workers were subdivided into three groups according to their reasons for leaving night work: (i) directly related to work, (ii) related to better reconcile with studies or another job, and (iii) related to health, sleep, fatigue or stress. Binomial logistic regression was performed, with adjustment for potential confounders. A dose response gradient was observed between current night work and MPD (OR=1.5; 95% CI: 1.1-2.2 and OR=2.1; 95%CI: 1.5-3.1 for those who worked up to five nights and six or more nights per 2-week span, respectively). Potential detrimental effects of night work were confirmed. The association between working at night and MPD was not restricted to current night workers as workers who left night work for health/fatigue/sleep/strain also showed higher chances of reporting MPD (OR=1.8;95%CI:1.14-2.90). Results contribute to the scientific debate on the impact of night work on health and wellbeing.