A 79-year-old woman is referred by her primary care physician for an evaluation regarding a possible psychiatric diagnosis. Until now, she has had an unremarkable medical and psychiatric history. For the past 4 months, the family has observed increasing confusion. She has been repeating statements that she has just made, evidences increasing forgetfulness, such as misplacing her keys and checkbook, and, on one occasion, went to the grocery store but could not remember which items she needed to purchase. There has also been a history of insomnia, some irritability, and she becomes agitated over trivial issues related to household activities. She has had a reduction in appetite and has lost 5 pounds. Furthermore, she has complained of fatigue and a decrease in energy. Her husband indicated that she rarely drinks alcohol. She has not mentioned suicidal ideation directly but she has become increasingly concerned that her affairs are in order. Two of her friends died in the previous year and one was admitted to a nursing home.