The Effects of Circadian Rhythm Disruption on Mental Health and Physiological Responses among Shift Workers and General Population

Background: The effect of circadian disruption on the bio-psychological clock system has been widely studied. However, the mechanism and the association of circadian rhythm disruption with mental health and physiological responses are still unclear. Therefore, this study was conducted to investigate the effects of circadian rhythm disruption on mental health and physiological responses among shift workers and the general population. Methods: A total of 42 subjects participated in this quasi-experimental study. Participants were divided into a group of shift workers (n = 20) and a general population group (n = 22). Polysomnography tests, blood tests (cortisol, triglycerides and glucose), and psychological tests (Abbreviated Profile of Mood States, General Health Questionnaire-28, Working Memory and Processing Speed Indexes of the Wechsler Adult Intelligent Scale (WAIS-IV) were used to examine the effects of circadian rhythm disruption. Results: The results showed a significant relationship between circadian rhythm disruption and mood (r = 0.305, p < 0.05). The findings of this study also indicated that there was a significant effect of circadian rhythm disruption on mood (F(2,40) = 8.89, p < 0.001, eta(2) =0.182), processing speed (F(2,40) = 9.17, p < 0.001, eta(2) = 0.186) and working memory (F(2,40) = 4.963, p < 0.01, eta(2) = 0.11) in shift workers and the general population. Conclusions: Our findings showed that circadian rhythm disruption affects mood and cognitive performance, but it does not significantly affect psychological wellbeing and physiological responses. Future studies are warranted to examine moderator and mediator variables that could influence the circadian rhythm disruption.