Venlafaxine for Depression in Alzheimer's Disease (DIADs-3)

This study will test the use of venlafaxine to treat the depression in Alzheimer's Disease. Venlafaxine works by increasing natural substances in the brain (serotonin and norepinephrine) that help maintain mental balance. Alzheimer's disease (AD) is the commonest neurodegenerative disease of aging and the cause of major financial and emotional burden to patients, families and caregivers, and society. Depression is a very common symptom of AD, affecting as many as 50% of patients over their illness. Depression in AD (Alzheimer's disease) contributes greatly to patient disability and caregiver distress. Neither psychosocial interventions nor psychotropic medications have proven effective to date for the treatment of depression in AD.Venlafaxine is approved by the U.S. Food and Drug Administration (FDA) for the treatment of major depression but it is not known whether or not it can help depression in Alzheimer's Disease.