Alzheimer’s disease (AD) is a brain disorder that affects a person’s thoughts, memory, speech, and ability to carry out daily activities. With AD the loss of brain tissue that leads to loss of mental abilities may also disrupt the sleep/wake cycle, which may cause sleep problems, nighttime wandering, and agitation.AD affects an estimated 4.5 million Americans, according to the National Institute on Aging at the National Institutes of Health. Alzheimer’s disease is not a normal part of aging but the risk of developing it goes up with age. It usually begins after age 60 and the risk nearly doubles with every 5 years of age after age 60, according to the U.S. Surgeon General. Because of the “graying” of Americans, the number of Alzheimer’s patients is expected to increase dramatically in the coming years.