An estimated 300 to 400 U.S. doctors kill themselves each year, which some doctors say is because the stigma of mental illness is magnified in a profession that prides itself on stoicism and bravado. And because doctors have easy access to prescription drugs and a precise knowledge of both how the body works and the amount of a drug needed for an overdose to stop breathing and halt the heart, it can be a dangerous combination. The American Medical Association has even called physician suicide "an endemic catastrophe."