It’s estimated that at least 400 U.S. doctors kill themselves every year. Many are struggling with depression, anxiety, or addiction. Greg Miday was a promising young doctor with a prestigious oncology fellowship in St. Louis. He spoke conversational Spanish, volunteered with the homeless, and played the piano as if he’d been born to it. He had rugged good looks, with dark wavy hair and a tall, athletic build. Everybody—siblings, patients, friends, nurses, professors, fellow doctors, and above all, his physician-parents—adored him. On the evening of June 21, 2012, Greg drew a bath, lit candles, and put his iPod on speaker....