In this May 11, 2016 photo, University of Massachusetts Medical School student Dylan Perry, far right, demonstrates a nasal Naloxone for emergency treatment of opioid overdose to actor-patients coping with addiction during a simulation at the medical school in Worcester, Mass. Many U.S. medical schools are expanding their training to help students fight opioid abuse. New training programs at many schools teach students to prescribe opioid painkillers only as a last resort, and to evaluate all patients for signs of drug abuse. (AP Photo/Elise Amendola)