CHICAGO/NEW YORK (Reuters) - On a recent shift at a Chicago emergency department, Dr. William Sullivan treated a newly homeless patient who was threatening to kill himself. "He had been homeless for about two weeks. He hadn't showered or eaten a lot. He asked if we had a meal tray," said Sullivan, a physician at the University of Illinois Medical Center at Chicago and a past president of the Illinois College of Emergency Physicians. Sullivan said the man kept repeating that he wanted to kill himself. "It seemed almost as if he was interested in being admitted." Across the country,...