U.S. President Barack Obama hugs Kate Grubb, whose daughter died from an opioid overdose earlier this year, during a signing ceremony for the 21st Century Cures Act at the White House in Washington, DC, U.S. December 13, 2016. REUTERS/Kevin Lamarque 

U.S. President Barack Obama boards Air Force One to return to Washington after participating in a National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama clasps hands with Crystal Oertle, in recovery for a substance use disorder and is dedicating her new life to helping others, during a National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama speaks during a National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque TPX IMAGES OF THE DAY

U.S. President Barack Obama waves as he arrives to take part in a National Rx Drug Abuse and Heroin Summit moderated by CNN Chief Medical Correspondent Sanjay Gupta (L) in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama reacts to a comment from Justin Riley (L), president and CEO of Young People in Recovery, during the National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama speaks during a National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama speaks during a National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama listens to Justin Riley, president and CEO of Young People in Recovery, speak during the National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama speaks during a National Rx Drug Abuse and Heroin Summit moderated by CNN Chief Medical Correspondent Sanjay Gupta (R) in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama listens to Justin Riley, president and CEO of Young People in Recovery who has been in long-term recovery since 2007, speak during the National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama participates in a National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama participates in a National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama participates in a National Rx Drug Abuse and Heroin Summit in Atlanta, Georgia March 29, 2016. REUTERS/Kevin Lamarque

U.S. President Barack Obama shakes hands as he arrives in Atlanta, Georgia, to participate in a National Rx Drug Abuse and Heroin Summit March 29, 2016. REUTERS/Kevin Lamarque