The purpose of this study is to determine the safety and efficacy of escitalopram (Lexapro) using 10 or 20 mg daily in patients with Alzheimer's disease who are also experiencing agitation.

This study is designed for men and women over 60 who have an established diagnosis of mild to severe Alzheimer's disease and who also present behaviors of agitation such as restlessness, physical aggression, yelling and socially inappropriate interactions. While nonpharmacologic interventions are preferable, many times they are not effective alone. Each consented subject will be enrolled in a 12 week study with escitalopram, 10 or 20 mg per day. Each subject will be evaluated using rating scales designed for symptoms of Alzheimer's and agitated behavior. Each subject will also undergo physical and neurological examinations, laboratory tests and monitoring of side effects of escitalopram.

Inclusion Criteria:

• Dementia of Alzheimer's type with behavioral disturbance
• Mild to severe cognitive impairment
• Age over 60
• Medically stable
• Agitation present both at screening and baseline
• Agitation not responsive to simple nonpharmacologic interventions and lasting at least 2 weeks prior to enrollment.
• Available Health Care Proxy or other legal representative to give informed consent, and patient assent.
• No planned change in environment for duration of study
• At least one reliable caregiver

Exclusion Criteria:

• Any intercurrent medical problem that could explain the agitation
• History of major depression or bipolar preceding the onset of dementia
• Other major psychiatric illness preceding the onset of dementia or mental retardation
• Other dementias
• History of alcohol abuse or dependence in the last 2 years
• Delirium (or history of delirium in the last 8 weeks)
• Treatment with other psychotropic drugs except those permitted in the protocol. Patients already treated for agitation with psychotropic medication must be able to successfully discontinue it and tolerate a washout period of no less than 1 week.
• Treatment with non-psychotropic, centrally active drugs believed to contribute to patient's agitation.
• Severe psychiatric symptoms requiring psychiatric hospitalization or suicidal, homicidal potential.
• History of intolerance to citalopram
• Noncompliance with oral medication or inability to take oral medication
• Modified Hachinski score of 4 or greater