• The primary objective is to determine whether quetiapine can increase total sleep time and reduce time awake in patients with AD and sleep disturbance.
  

• The secondary objectives:
  
• Dose-response relationship of quetiapine and sleep in AD patients?
  
• Are there sleep architecture changes from quetiapine?
  
• Do the primary sleep variables change relative to placebo at any weekly time or dose point?
  
• Are caregivers, blind to treatment status, able to detect changes in sleep quality in the patients for quetiapine relative to placebo?
  
• Does quetiapine used at single bedtime dosing for potential nighttime soporific effect have a measurable impact on neuropsychiatric symptoms other than insomnia?
  

Quetiapine is frequently used to treat psychosis in patients with Alzheimer's disease (AD) and other dementias. These patients commonly have sleep disturbances that include nighttime awakenings with confused, agitated behaviors.1 These awakenings impose a great challenge for caregivers, especially family caregivers whose own sleep is disrupted as a result of the patient's awakenings.2 Sleep disturbance can lead to nursing home placement3 and may add to cognitive impairment of patients.

There is no medication proven to be safe and effective in the treatment of sleep disorders in patients with dementia. Antipsychotic medications are often prescribed at bedtime in the hopes that they will aid sleep and reduce agitation and psychosis associated with these awakenings. Sleep disturbance is more common in AD patients with moderate to severe disease,2 and these patients are more likely to have psychosis and to be recruited from long-term care facilities. We recently conducted the only multicenter clinical trial of a drug for sleep disturbance in AD.4 The study, completed under the auspices of the NIA's Alzheimer's Disease Cooperative Study, investigated melatonin as a sedative-hypnotic agent for AD patients. We found melatonin to be of no benefit on objective measures, although there were positive trends in the data and a significant improvement on subjective measures (caregiver ratings of patients' sleep) in one of the melatonin groups relative to placebo. No other large trial in AD subjects has been reported in the literature for drugs with potential benefit for AD patients with sleep disturbances. There are several reasons why this population needs to be specifically studied. Patients with AD tend to have highly fragmented sleep, with many nocturnal awakenings. They have significant daytime sleepiness that might affect daytime cognitive function and behavior. These patients tend to be older, with sensitivity to drug side effects.

People with neurodegenerative diseases such as AD may respond differently to CNS-active medications. Finally, this population represents a large and growing cohort of patients that deserve individual study of their unique problems.