Abstract
Background: Sleep is one of the most important recovery mechanisms available to humans, allowing for recovery from daily strains, and therefore a prerequisite for health. Many workers complain that they are unable to get to sleep at night, and report poor sleep maintenance due to unwanted, ruminative thoughts and concerns about work-related issues. The present study investigated the effects of ruminative thinking on sleep, using self-reported diaries. Method: One-hundred and seven school teachers were asked to keep a diary record of their thoughts about work over a workday evening and were monitored hourly from 17.00 hrs until bedtime. Each individual also completed a diary assessment of their sleep patterns over the same night. Using information obtained from the diaries the sample was divided into high ruminators (those who thought about work issues a lot at bedtime) and low ruminators (those who thought about work issues little at bedtime) using tertile splits. Only individuals who did not work in the hour before bedtime were included in the analysis. Results: Logistic regression analysis revealed (after adjusting for age and gender), that high compared to low ruminators were: 3.5 time more likely to report 'difficulty falling asleep', 4.7 time more likely to report 'difficulty waking up', 5.7 times more likely to report 'difficulty getting back to sleep if awoken during the night', 6.8 times more likely to report 'restless sleep' and 3.4 times more likely to 'feel unrefreshed after awaking'. Relative to the low ruminators, high ruminators also reported that they had thought about work related issues - while trying to fall asleep (p < 0.001), and in the morning before they got out of bed (p < 0.5). Conclusion: Ruminating about work-related issues appears to be associated with self-reported sleep disturbance. It is important therefore that individuals learn to 'switch-off' from work during the evening in order to obtain good quality sleep.