• Actigraph measures [ Time Frame: Measured 3 times over 6 months ] [ Designated as safety issue: No ]
  
• Caregiver reports of patient behavioral disturbances at night [ Time Frame: Measured 3 times over 6 months ] [ Designated as safety issue: No ]
  

• Caregiver sleep [ Time Frame: Measured 3 times over 6 months ] [ Designated as safety issue: No ]
  
• Patient daytime sleepiness, behavioral problems, and residential status [ Time Frame: Measured 3 times over 6 months ] [ Designated as safety issue: No ]
  

Nocturnal disturbances, such as getting out of bed repeatedly, having hallucinations, talking or singing in bed, and waking up confused are common among patients with AD. Such nocturnal disturbances are associated with increased physical and psychological morbidity in both AD patients and their caregivers and are a major risk factor for patient institutionalization. Nonpharmacologic treatments for these disturbances are needed. This study will assign AD patients to one of four different treatments to determine which is most effective in reducing nocturnal disturbances.

This study will last 6 months. Participants will be randomly assigned to a walking program, a light exposure program, a "Nite-ad" program, combining the walking and light exposure programs, or routine AD care with nocturnal disturbance education. Walking program participants will have three 1-hour visits with a therapist over an 8-week period. The therapist and the participant will set an initial daily walking goal and develop a plan for gradually increasing the participants' walking to 30 minutes/day, to be increased at a participant-selected pace. Pedometers will be given to participants to monitor daily activity. The therapist will also discuss exercise safety and will review ways to prevent muscle soreness. Light program participants will also have three 1-hour visits with a therapist over 8 weeks. The therapist will develop a daily, caregiver-supervised light exposure plan requiring participants to sit in front of a light box for 1 hour every day. Nite-ad program participants will have six 1-hour visits with a therapist over 8 weeks; their visits will include both the walking and the light exposure program visits. Participants assigned to receive education about night disturbances associated with Alzheimer's disease will not receive any treatment in the study, but will continue their usual treatment outside of the study.

Participants will be assessed at study entry and at Months 2 and 6. The sleep patterns of both the patients and the caregivers will be measured. Caregiver reports of patients' night-time behavioral disturbances and readings from an actigraph, a small electronic device worn by participants that records and reports their levels of activity at night, will be used to assess participants. A follow-up visit will occur 6 months after study completion; at the follow-up visit, participants and their caregivers will be interviewed about the participants' nocturnal disturbances.