Anne Jones, 62, and Robin Jones, 73, at their home in Menlo Park, Calif. He took a test that revealed proteins typical of Alzheimer's disease. Ramin Rahimian for NPR hide caption

itoggle caption Ramin Rahimian for NPR

Insomnia, feeling isolated, and bursts of anger are symptoms of the anxiety disorder known as PTSD. iStockphoto.com hide caption

itoggle caption iStockphoto.com