Nighttime agitation and sleep disturbance in persons with dementia (PWD) causes patient suffering, may accelerate cognitive decline, leads to burdened caregivers, and is costly to manage. Pharmacological interventions are primarily antipsychotics and hypnotics. Effectiveness is unconvincing, and these drugs are associated with falls, strokes, and death. There is a lack of tailored, effective, and sustainable treatments for nighttime agitation and sleep disturbance in PWD. The investigators approach to this problem is innovative because, unlike pharmacological interventions in the past, it tailors the intervention to a treatable condition, restless legs syndrome (RLS), which may be causing the nighttime agitation and sleep disturbance. In previous research, the investigators showed that about 24% of PWD have an undiagnosed sleep disorder, RLS; that RLS was associated with nighttime agitation and sleep disturbance in PWD; and the investigators developed and validated an RLS diagnostic and outcome measure suitable for PWD. In order for the investigators' work to significantly impact standards of clinical practice, evidence is needed on whether RLS behaviors cause nighttime agitation, and if treating RLS behaviors reduces or stops nighttime agitation and improves sleep in PWD. The investigators have chosen gabapentin enacarbil (GEn), as the RLS treatment in this research because it is FDA approved for RLS and has a favorable safety profile. The investigators propose an 8-week, double-blind placebo-controlled randomized clinical trial of GEn versus placebo in 156 community-dwelling and long-term care facility residents with nighttime agitation, sleep disturbance, and RLS. The specific aims of this pilot study are to: 1) Determine the effect of GEn, compared to placebo, on nighttime agitation (primary endpoint) in PWD with RLS. The investigators hypothesize that compared to the placebo control group, the treatment group will have fewer nighttime agitation behaviors. 2) Describe the safety profile of GEn compared to placebo in this population. 3) Estimate the effect size of GEn compared to placebo on nighttime sleep and RLS behaviors. The investigators hypothesize that compared to the placebo control group, the treatment group will have better nighttime sleep and fewer RLS behaviors. 4) Explore whether frequency of RLS behaviors is a causal mechanism for nighttime agitation. The investigators hypothesize that frequency of RLS behaviors will mediate the effect of GEn on nighttime agitation behaviors. The results of this study and future definitive trials have the potential to radically shift and drastically improve standards of clinical practice for assessment and treatment of three highly prevalent, often comorbid conditions in PWD: RLS, nighttime agitation, and sleep disturbance. For scientists, the results may provide insight into the mechanism for nighttime agitation and sleep disturbance in PWD and inform future research. For PWD, the findings may result in less nighttime agitation and discomfort from RLS, improved nighttime sleep, and improved sleep may enhance daytime cognitive functioning and quality of life. Application of the findings into the home setting may result in fewer nursing home admissions for PWD and less caregiver burden because the PWD (and their caregivers) can get more sleep.

COVID-19 Modifications - The impact of COVID-19 social distancing on the well-being of community-dwelling older adults with Alzheimer's disease related dementia and their family caregivers who live with them is unknown. They have been confined to their homes. Social and physical activities may be restricted to television and phone calls, and exposure to bright outdoor light is likely infrequent or absent. Exposure to sunlight and both social and physical activity are critical for healthy sleep patterns. For those with the neuropsychiatric symptom of excessive motor activity, such as agitated pacing, being restricted to the home may cause even greater suffering. In addition, family caregivers may be exhausted, stressed, and burdened, even more than usual, because they have not had access to support services such as adult day care, respite, and senior centers. All of the factors associated with social distancing - lack of understanding of what is happening, inadequate or no caregiver support services, isolation, restricted movement, insufficient sunlight, social and physical activity, caregiver exhaustion, and increased caregiver burden - may adversely impact the wellbeing of older adults with Alzheimer's disease related dementia. Further, because older adults with dementing illness are unable to cognitively and verbally express their distress, it is likely that social distancing will increase agitation behaviors, worsen sleep patterns, and increase the need for antipsychotic and sedating medications to manage agitation behaviors and sleep disturbances. We now examine the impact of social distancing on the well-being of older adults with Alzheimer's disease related dementia and their family caregivers who are living together in community settings. A sample of 30 family caregivers will be recruited for qualitative phone interviews to explore the impact of social distancing on the well-being of older adults with Alzheimer's disease related dementia. The specific aims are to: 1) explore the impact of social distancing on nighttime agitation, sleep patterns, and use of antipsychotics and other sedating medications; and 2) ask caregivers for their recommendations on ways to minimize the impact of social distancing on the well-being of older adults with Alzheimer's disease related dementia and their caregivers.

During the time-period where limitations are placed on in-person interactions, researchers will conduct all recruitment, consent, data collection, and intervention activities with participants using remote procedures rather than any procedure that would require in-person interaction. After the university releases restrictions on in-person research activities, researchers may resume in-person activities and/or continue optional telepresence interactions.