Nighttime agitation in persons with Alzheimer’s disease causes patient suffering, distresses caregivers, and often results in prescriptions for harmful antipsychotics. Effective treatments are lacking because of our limited knowledge of the etiology of nighttime agitation. We propose a clinical trial to better elucidate whether a sleep disorder, restless legs syndrome, may be a mechanism for nighttime agitation, and if treatment with gabapentin enacarbil (Horizant®) reduces nighttime agitation, improves sleep, reduces restless legs syndrome behaviors, and reduces antipsychotic medications.