Insomnia and daytime neuropsychological test performance in older adults

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 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).

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.

The association of EMA among older adults with decreased executive functioning and underlying mechanistic factors should be further investigated.