Effects of Decreased Opportunity to Sleep on Cognitive Performance and Mood by Sex in Older Adults

Objectives: The goal of this study was to compare older adults (ages 60 to 80) with a fixed sleep schedule compared to a restricted sleep schedule. The purpose was to determine if reducing one's sleep by an hour each night for 12 weeks, led to worse cognition and mood over time. Study Design: The study contained two groups: older adults with their sleep restricted and older adults with their sleep un-restricted. Participants were recruited by researchers at Arizona State University and The University of Arizona by advertising in newspapers, on flyers in senior centers, and on radio stations. After rigorous screening for health conditions, current sleep patterns and depression, individuals entered the study. Participants completed the Geriatric Depression Scale after two weeks of baseline, and again after treatment week 14 of the study. Likewise, males and females performed three cognitive tests after two weeks of baseline, and again after treatment week 14 of the study. These cognitive tests included Stroop Color and Word Test, Trail making and PVT. Results: The depression scale and three cognitive tests showed that there was no significant difference with cognition and mood over 14 weeks between individuals with a fixed sleep schedule compared to a restricted sleep schedule. Conclusions: Reducing older adult's sleep duration by an hour each night for 14 weeks does not produce negative effects, and does not provoke signs of depression or weakened cognition.