Insomnia and daytime neuropsychological test performance in older adults

Objectives/Background: There is good documentation of the impact of insomnia on daytime cognitive function based on self-reports, but not on neuropsychological test performance. The study investigated the association of difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and early morning awakening (EMA) complaints with daytime domain-specific neuropsychological performance in older adults. Participants/Methods: Participants were 859 older adults (mean 71.9 years) in the Singapore Longitudinal Ageing Studies. They were interviewed and assessed at community-based eldercare activity centres and completed a sleep survey questionnaire and a battery of neuropsychological tests (Digit span, Rey Auditory Verbal Learning Test, Story memory, Brief Visuospatial Memory Test-Revised, Color Trails Test (1 and 2), Block design, and Verbal fluency). Results: Insomnia complaints were present in 18.0% (n = 155) of participants. Controlling for the presence of other insomnia complaints, psychosocial and medical variables, and depression, EMA was independently and significantly associated with worse executive functioning (p = 0.031). DIS and DMS were not independently associated with poorer performance on any cognitive domain. Conclusion: The association of EMA among older adults with decreased executive functioning and underlying mechanistic factors should be further investigated. (C) 2015 Elsevier B.V. All rights reserved.