Impact of working hours on sleep and mental health.

Background: The number of hours people are required to work has a pervasive influence on both physical and mental health. Excessive working hours can also negatively affect sleep quality. The impact at work of mental health problems can have serious consequences for individuals' as well as for organizations' productivity.

Aims: To evaluate differences in sleep quality and anxiety and depression symptoms between longer working hours group (LWHG) and regular working hours group (RWHG). To examine factors influencing weekly working hours, sleep quality and anxiety and depressive symptoms.

Methods: Participants were divided into two groups, RWHG and LWHG, based on working hours, with a cut-off of 48 h per week. We used the Hospital Anxiety and Depression Scale (HADS) to assess anxiety and depression symptoms and the Pittsburgh Sleep Quality Index (PSQI) to measure the quality and patterns of sleep.

Results: The response rate was 23%. Among the 429 study participants, those in the LWHG group (n = 256, 53%) had significantly more depressive and anxiety symptoms and worse sleep quality than those in RWHG (n = 223, 47%). Working time was significantly positively correlated with higher corporate position and HADS scores. Moreover, HADS scores were positively correlated with PSQI scores and negatively correlated with age.

Conclusions: This study suggests that longer working hours are associated with poorer mental health status and increasing levels of anxiety and depression symptoms. There was a positive correlation between these symptoms and sleep disturbances.