Who Cares about Sleep in Older Adults?

The idea voiced by Thomas Dekker that “Sleep is that golden chain that ties health and our bodies together” may ring especially true for older adults. At its most basic level, sleep helps to maintain cognitive functioning by serving as the brain’s “housekeeper” and facilitating the daily removal of metabolic waste (Xie et al., 2013). Accordingly, the consequences of sleep impairments for brain health are many-fold, including short-term cognitive impairment and longitudinal cognitive-decline (Dzierzewski, Dautovich, & Ravyts, 2017). Beyond the impact on cognitive functioning, healthy sleep is a critical factor predicting better mental well-being, increased ability to perform activities of daily living, reduced fall risk, better self-reported health status, and reduced risk of hospitalization, among many, many, other outcomes (Brassington, King, & Bliwise, 2000; Kaufmann et al., 2013; Mccrae et al., 2008; Newman, Enright, Manolio, Haponik, & Wahl, 1997). In fact, it is hard to find a domain of mental or physical functioning that is not dependent on sleep for older adults. Nonetheless, sleep disorders are prevalent in older adults, with epidemiological evidence suggesting that over 50% of older adults suffer from one of several sleep disorders (Dzierzewski, Rodriguez Tapia, & Alessi, 2017). As such, sleep disorders are among the most common disorders of aging; however, they are often overlooked by both clinicians and researchers as mere symptoms of other ‘primary’ disorders. The good news is that psychological treatments for late-life sleep disorders have achieved the distinction of being evidence-based (McCurry, Logsdon, Teri, & Vitiello, 2007), and have even been acknowledged by the American College of Physicians as the first-line treatments for insomnia (Qaseem, Kansagara, Forciea, Cooke, & Denberg, 2016). Unfortunately, there still remains much to be done in terms of increasing our basic understanding of, and applied skills in working with, sleep in older adults. The overarching goal of this special issue is to shed much needed light on the important issues related to sleep in older adults.

Our issue opens with a topic that is an emerging area of focus in sleep research—intraindividual variability or fluctuations that occur within individuals (Dillon et al., 2015). Variability is an important but often overlooked factor to consider when behaviors vary significantly day-to-day. In their original research article, Paterson and colleagues ask whether sleep schedule regularity, the extent that older adults are consistent with their bed and wake times, is associated with greater sleep sufficiency (greater than 7 hours per night; Paterson, Reynolds, & Dawson, 2017). Using a sample of Australian community-dwelling adults (N = 312) and a single time point telephone survey, the authors found that bedtimes and/or wake-times that varied greater than 60 mintues on average were associated with at least a twofold increased risk for obtaining insufficient sleep. These results are fascinating because even after controlling for relevant covariates, the authors identified a behavioral factor that is salient to older adults and amenable to change—maintaining consistent bed and wake times. Given the elusive target of sufficient sleep, the identification of a sleep health behavior that shows potential to address sleep insufficiency has significant implications.

Next, an original research article by Ravyts and colleagues also used an observational design but with the added strength of a microlongitudinal approach (across 7 days) to assess the association between variability in self-reported pain and sleep outcomes (Ravyts et al., 2017). Not only is pain a common health problem affecting older adults, it can also fluctuate significantly day-to-day. This rollercoaster of pain symptoms is distressing for the affected individual and can disrupt sleep. Using a community-dwelling sample of older adults (N = 82) the authors asked whether day-to-day fluctuations in pain uniquely contribute to sleep outcomes compared to overall average levels of pain. Inconsistency in pain predicted poorer sleep, while average pain was not associated with sleep outcomes. These associations held even after controlling for known predictors of sleep disturbance such as age, gender, and depression. Taken together, these articles suggest that the examination of mean levels may not reflect the complete picture of sleep health in the older adult population. It is worthwhile to consider the unique role of variability in sleep and related constructs as predictors of sleep in community-dwelling older adults.

The next two articles in the special issue focus on older adults with insomnia, which is the most common sleep disorder in late-life (Rodriguez, Dzierzewski, & Alessi, 2015). Fung and colleagues examined cognitive expectancies for sleep medication as predictors of sleep medication use in a sample of older adults with insomnia who were regular users of sleep medication (N = 23) or not (N = 135; Fung et al., 2018). This investigation is particularly noteworthy as most older adults with sleep complaints continue to be treated with sleep medication in light of the overwhelming scientific evidence of the negative consequences associated with regular use of sleep medication in older adults and the universally accepted stance that psychological treatments should be the first-line treatment for late-life insomnia. Not surprisingly, increased cognitive expectancies were associated with an increased likelihood that older adults with insomnia were regular users of sleep medication. The authors suggest that clinically targeting cognitive expectations for sleep medication could help reduce the number of older adults using sleep medications on a regular basis, which is a noble goal worth considerable investment.

Next, Cassidy-Eagle and colleagues present the results of a pilot investigation of the neuropsychological outcomes of treating insomnia in older adults (N = 28) with mild cognitive impairment (Cassidy-Eagle, Siebern, Unti, Glassman, & O’Hara, 2018). While the cognitive consequences of disturbed sleep in older adults are generally well characterized, efforts to intervene on cognitive functioning through sleep have been few and far between. The authors embarked on this critical next phase of research and found that older adults who received cognitive-behavioral treatment for insomnia displayed selective improvement in a measure of inhibition. Our hope is that these findings will inspire future investigations into the potential secondary benefits of improving sleep in older adults.

Moving from articles focused specifically on insomnia, the next three articles in our special issue examine the unique sleep challenges facing vulnerable older adults and their caregivers. These articles span the continuum of sleep research, beginning with questions about assessment, followed by an examination of predictors of sleep disruption, and ending with a study of the acceptability and feasibility of a sleep intervention.

First, the assessment of sleep is complex, with a myriad of both subjective and objective options that vary in feasibility and thoroughness. Adding to this complexity is the frequent lack of concordance between subjective and objective measures. Hughes and colleagues addressed these measurement issues in their original article comparing subjective and objective sleep measures in vulnerable older adults (Hughes et al., 2017). Specifically, this article examined sleep in older adults who are at risk for cognitive and functional decline and attended a Veterans Administration Adult Day Health Care Program (N = 59). Insomnia is a prevalent condition within this population, with diagnosis based on patient self-report. Unfortunately, existing measures have limited validation within this sample. To address these concerns, the authors compared subjective questionnaires commonly used to assess insomnia with objective sleep measures. As expected, disturbed sleep was common within this group. However, there was no agreement between subjective and objective measures of sleep. Older adults reported significantly worse sleep compared to what was observed with actigraphy. These results point to the complexity of sleep measurement within this population and highlight the importance of both the subjective perception of sleep and the utility of objective observations.

The second original research article focused on caregiver sleep and begins with the John Milton quote “What Hath Night to Do With Sleep?”. Yes indeed! As anyone who has engaged in caregiving can attest, sleep can become a tenuous goal when coping with the stress and challenges of caregiving. In fact, the sleep of caregivers of individuals with dementia can become strikingly similar to adults with insomnia (Leggett, Polenick, Maust, & Kales, 2017). Caregivers for persons with dementia are often aging themselves, which only increases the risk for sleep disruption. Given a predisposition for caregivers to develop sleep disruption, the authors asked if there are any specific characteristics of caregivers or the individuals they are caring for that increase the risk of disturbed sleep. With a sample of 1,063 caregivers for 717 individuals with dementia, the authors examined 13 possible predictors of caregiver sleep as assessed with a single sleep item. Surprisingly, the relationship and hours spent caring were not significant predictors of caregiver sleep. Rather, a combination of both care receiver and caregiver characteristics appear to have implications for caregiver sleep. Importantly, caregivers’ sense of self and perception of the emotional difficulty of caregiving emerged as potentially powerful intervention targets.

Finally, given the known costs of caregiving on sleep, there is a need to effectively improve sleep for this population. Although, as mentioned earlier, effective interventions exist, these interventions typically target the caregiver or the care receiver, reducing the potential benefit of a dyadic intervention. Song and colleagues took the initial step of developing a dyadic intervention by conducting a qualitative study using a focus group to explore caregivers’ attitudes towards an intervention for both members of the dyad (Song et al., 2017). Five caregivers of individuals attending a Veterans Administration Adult Day Health Care Program participated in a focus group discussion. What follows is a fascinating insight into care-givers’ attributions about the causes of sleep problems and their thoughts about pharmacological and behavioral sleep interventions. For example, common behavioral recommendations like maintaining a consistent bed and wake time and limiting daytime naps were considered challenging. For anyone developing or conducting a caregiver and care receiver sleep intervention, the information Song and colleagues collected is a must read.

As stated above, poor sleep is associated with a host of negative consequences in late-life—suicidality being one of the more dire of these consequences. In the last article of the special issue, Webb and colleagues report the results of an online survey with older adults (N = 134) focused on sleep, activities of daily living (ADL), and mood and suicidality (Webb, Cui, Titus, Fiske, & Nadorff, 2017). Their results confirm the link between poor sleep, both in terms of insomnia symptoms and nightmares, and depressive symptoms and suicidality in older adults. Such findings only reinforce the importance of being mindful of sleep disturbances when working clinically with older adults. Interestingly, they also found that decreased levels of ADL appear to be one potential mechanism of the insomnia—depressive symptoms relationship. Examination of potential mechanisms linking poor sleep with mood disturbances and suicidality is a critical ‘next step’ and the authors have begun to shed light on how poor sleep might be associated with depressed mood.

In summation, it is our hope that after reading the articles contained in this special issue, you—the reader—will care about sleep in older adults.