Predicting sleep quality from stress and prior sleep - A study of day-to-day covariation across six weeks
ABSTRACT The connection between stress and sleep is well established in cross-sectional questionnaire studies and in a few prospective studies. Here, the intention was to study the link between stress and sleep on a day-to-day basis across 42 days.
Fifty participants kept a sleep/wake diary across 42 days and responded to daily questions on sleep and stress. The results were analyzed with a mixed model approach using stress during the prior day to predict morning ratings of sleep quality.
The results showed that bedtime stress and worries were the main predictors of sleep quality, but that, also, late awakening, short prior sleep, high quality of prior sleep, and good health the prior day predicted higher sleep quality.
Stress during the day predicts subsequent sleep quality on a day-to-day basis across 42 days. The observed range of variation in stress/worries was modest, which is why it is suggested that the present data underestimates the impact of stress on subsequent sleep quality.
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ABSTRACT: BACKGROUND: In spite of the apparently bidirectional relationship between daytime emotions and nocturnal sleep quality, relatively few studies have examined the day-to-day co-variation of daytime emotional states and sleep quality. PURPOSE: In order to address this issue, we used a 7-day prospective design allowing for the simultaneous investigation of the bidirectional link between sleep quality and affective states. METHOD: Seventy-five healthy university students completed a daily log during 7 days, reporting subjective sleep quality after their final morning awakenings. Eight hours later, they completed the Positive and Negative Affect Schedule measuring daytime affective states. Multilevel modeling was applied in order to examine level 1 (day-to-day co-variation of sleep quality and affective states within individuals) as well as level 2 (averaged between-subjects) effects. RESULTS: Individuals reporting poor sleep quality (on average) were characterized by lower positive and higher negative affect during daytime. Similarly, higher positive and lower negative affect (on average) predicted better subjective sleep quality during the assessment period. Moreover, daily ratings of positive and negative affect were related to the subjective sleep quality of the preceding night: On occasions in which participants reported poor (below average) sleep quality, they also reported lower positive and higher negative affect during the day. Nevertheless, daytime positive and negative affective states did not predict subsequent sleep quality ratings. CONCLUSION: These findings suggest daily dynamic associations between subjective sleep quality and next day's emotional states in a group of healthy individuals, while in the inverse, the co-variation between daytime affective states and subsequent sleep quality was not supported.International Journal of Behavioral Medicine 01/2015; DOI:10.1007/s12529-015-9464-4 · 2.63 Impact Factor
Stress and Health 12/2014; 30(5):425-30. DOI:10.1002/smi.2624 · 1.34 Impact Factor
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ABSTRACT: Objectives This study evaluated the effectiveness of a stress management intervention combining individual cognitive behavioral therapy (CBT) with a brief workplace intervention on self-reported measures of sleep and cognitive functioning among patients on sick leave due to work-related stress complaints. Methods Participants were patients referred to the regional Department of Occupational Medicine. Inclusion criteria were (i) sick leave due to work-related stress complaints and (ii) a diagnosis of adjustment disorder/reactions to stress or mild depression. Participants (N=137) were randomized to either an intervention (N=57) or control (N=80) group. The intervention comprised six sessions with a psychologist and the offer of a small workplace intervention. Questionnaires were answered at baseline and after 4, and 10 months. Results Symptoms were significantly reduced over time in both groups but there was no significant treatment effect on sleep or cognitive outcomes at any time point. From 0-4 months, there was a tendency for larger improvements in the intervention group with regards to sleep and cognitive failures in distraction. Although neither was significant, the results came close to significance depicting a small effect size (Cohen's d) on sleep complaints and distractions (but not memory). Conclusions The specific intervention was not superior to the control condition in reducing symptoms of sleep problems and cognitive difficulties at any time point during the 10-month follow-up period. Substantial improvements in symptoms over time were seen in both groups.Scandinavian Journal of Work, Environment & Health 11/2014; 40(6):569-81. DOI:10.5271/sjweh.3460 · 3.10 Impact Factor