When former President Ronald Reagan made the difficult announcement in 1994 that he had Alzheimer's disease, he may have saved his daughter's life. Patti Davis, 69, writes in her new memoir, "Floating in the Deep End," that she was struggling with depression and even contemplating suicide at the time her father publicly revealed his condition in a letter to the nation. "That could have been the last straw, but instead, it gave me something to reach for and to focus on," Davis told NBC News special correspondent Maria Shriver on TODAY Thursday. "That pulled me out of my own despair."