Z-Drugs for Sleep Disorders in Alzheimer's Disease

Inclusion Criteria: * 55 years of age or older * Diagnosis of probable Alzheimer's disease (AD) by National Institute of Neurological and Communicative Disorders and Stroke / the Alzheimer's Disease and Related Disorders Association Criteria * Hachinski Ischemia Scale less than 5 * Mini-Mental State Examination score of 0 to 26 * Actigraph evidence of a mean time immobile of less than 7 hours per night based on at least 7 nights of complete actigraph data collected over a single week * Four-week history of sleep disorder behaviors, occurring at least once weekly, as reported by the caregiver using the Neuropsychiatric Inventory (NPI) Nighttime Behavior scale * Sleep disturbance observed was not present before the diagnosis of AD * Other co-morbidities, especially delirium, depression, chronic pain and medication use may be present, but do not cooperate in the primary symptoms * Computed tomography or magnetic resonance imaging since the onset of memory problems showing no more than 1 lacunar infract in a nonstrategic area and no clinical events suggestive of stroke or other intracranial disease or normal * Stable medications for 4 weeks prior to the screening visit * Having a mobile upper extremity to which to attach an actigraph * Residing with a responsible spouse, family member, or professional caregiver who is present during the night and would agree to assume the role of the principle caregiver for the 3-week protocol * Ability to ingest oral medication and participate in all scheduled evaluations Exclusion Criteria: * Sleep disturbance associated with an acute illness, delirium or psychiatric disease * Clinically significant movement disorder, such as akinesia, that would affect actigraphic differentiation of sleep and wakefulness * Severe agitation * Unstable medical condition * Discontinuation of psychotropic or sleep medication within 2 weeks of the screening visit * Patient unwilling to maintain caffeine abstinence after 2:00pm for the duration of the protocol * Patient unwilling to comply with the maximum limit of 2 alcoholic drinks per day, and only 1 alcoholic drink after 6:00pm for the duration of the protocolo * Prior use of zolpidem/zoplicone for the treatment os sleep disturbances * Caregiver deemed to be unreliable to supervise the wearing of the actigraph, to administer study capsules at the proper time, to maintain the sleep diary, or to bring the patient to the scheduled visits