Date of Award


Document Type

Open Access Dissertation




College of Arts and Sciences

First Advisor

Jennifer M. C. Vendemia


There is consistent evidence demonstrating a “U-shaped” association between sleep duration and mortality, as well as several morbidities, such as increased systemic inflammation, decreased cognitive performance, and mood disturbances. Much of the information on long sleep is epidemiological in nature. The present study examined the associations between sleep duration and extension on mood, inflammation, and cognition. Ten (50-79 y) healthy adults who report sleeping 6-8 h were assessed on cognitive, emotional, and inflammatory measures in a cross-over design. Following a baseline week, participants were randomized to one of two three-week treatments: (1) a control treatment of habitual time in bed; and (2) a sleep extension treatment, in which participants extended their time in bed 2 hours longer than their median baseline time in bed. After 1 week of recovery, participants repeated the 1-week baseline and crossed over to the other treatment. Cognitive function was assessed after the first baseline and after each treatment. Sleepiness, fatigue, depression, anxiety, blood pressure, and heart rate were assessed weekly. Inflammation, glucose, and cholesterol were assessed following both treatments. As expected, sleep disturbance was associated with increased blood pressure and heart rate and negative changes in mood. Unexpectedly, more total sleep time was associated with improved blood pressure and heart rate. Total sleep time and sleep disturbance was not associated with cognition, or clinician-administered mood assessments. The results of the study have important public health relevance, as it provides more insight on the associations of sleep duration on physiological health.