Age differences in the role of cognitive versus somatic arousal in sleep outcomes.

The purpose of this study is twofold: (a) to determine whether daily or overall cognitive and somatic arousal better predict sleep and (b) to investigate age differences in the arousal-sleep relation. Fifty younger and 50 older adults completed the Pre-Sleep Arousal Scale and sleep diaries for 14 consecutive days. Analyses revealed mean arousal may better predict sleep regardless of age. However, daily arousal represents an important avenue of research as it may uncover lagged or coupling effects in the arousal-sleep relation. Significant age differences in the arousal-sleep relation suggest age-dependent associations between the type of arousal and sleep. Implications for assessment of sleep in older and younger adults are discussed.