Cognitive Performance Trajectories Before and After Sleep Treatment Initiation in Middle-Aged and Older Adults: Results from the Health and Retirement Study.

BACKGROUND: Sleep disturbances are associated with risk of cognitive decline but it is not clear if treating disturbed sleep mitigates decline. We examined differences in cognitive trajectories before and after sleep treatment initiation.

METHODS: Data came from the 2006-2014 Health and Retirement Study. At each of five waves, participants were administered cognitive assessments and scores were summed. Participants also reported if, in prior two weeks, they had taken medications or used other treatments to improve sleep. Our sample (N=3,957) included individuals who at HRS 2006 were >50 years, had no cognitive impairment, reported no sleep treatment, and indicated experiencing sleep disturbance. We identified differences between those receiving vs. not receiving treatment in subsequent waves, and among those treated (N=1,247), compared cognitive trajectories before and after treatment.

RESULTS: At baseline, those reporting sleep treatment at subsequent waves were more likely to be younger, female, Caucasian, to have more health conditions, to have higher BMI, and more depressive symptoms (all p's≤0.015). Decline in cognitive performance was mitigated in periods after sleep treatment vs. periods before (B=-0.20, 95% CI=-0.25, -0.15, p<0.001; vs., B=-0.26, 95% CI=-0.32, -0.20, p<0.001), and this same trend was seen for self-initiated and doctor-recommended treatments. Trends were driven by those with higher baseline cognitive performance-those with lower performance saw cognitive declines following sleep treatment.

CONCLUSIONS: In middle-aged and older adults with sleep disturbance, starting sleep treatment may slow cognitive decline. Future research should assess types, combinations, and timing of treatments most effective in improving cognitive health in later life.