Major depression is a very common health problem affecting older persons. The present standard of treatment is with medications called "antidepressants". Antidepressants have been studied extensively in older persons with normal brain function and have been shown to be effective. However, certain types of brain dysfunction called "executive impairment" (inability to do higher order thinking) may lead to poor treatment outcomes. This study will compare how older depressed people with different levels of executive impairment respond differently to standard antidepressant treatment. Knowing this information will lead to more rational targeting of available treatments, leading to improved treatment outcomes.

Inclusion Criteria:

• above the age of 65,
• speak English fluently,
• experience depression, AND
• not yet on active treatment.

Exclusion Criteria:

• active delirium,
• substance abuse,
• mental illness other than major depression,
• active CNS disease,
• unstable systematic medical disease, OR
• current of past psychotic disorder.