When it comes to the elderly, some of the most common diagnoses are Alzheimer's disease and depression. Up until recently, most people felt that anxiety disorders declined as people aged, but just the opposite is true. Most older adults with an anxiety disorder likely had one when they were younger. Anxiety in older adults returns when stresses and vulnerabilities unique to the aging process become evident: chronic physical problems, cognitive impairment and significant emotional losses.
Anxiety disorders in the elderly have been underestimated and not diagnosed for several reasons. One reason for this is that older patients are less likely to report mental illness symptoms and more likely to emphasize their physical complaints, which is common. That's why it's important for the adult loved ones or caregivers in their lives to pay close attention to see is any symptoms are present.
The following links take you to some excellent articles on anxiety and the elderly that offer great information, insight and advice that should prove helpful. The first one is called "Anxiety Often Missed in Elderly", followed by "Anxiety Disorders in the Elderly". Another great one is titled "Elderly Anxiety and Depression" and my last recommendation is titled "Elderly Parents Behavior- Dealing With Anxiety".