David Casarett, MD, director of hospice care at the Perelman School of Medicine at the University of Pennsylvania, spoke with NPR's "Weekend Edition" Sunday. He works with families as they try to navigate end-of-life decisions. At least once a week, Casarett says, one of his patients expresses a desire to end his or her own life. "It's a reminder to me that I have to stop whatever I was doing... and sit back down to try to find out what is motivating that request," he says. "Is it really a carefully thought out desire to die, or is it, as it is unfortunately many times, a cry for help?"