ALISON STEWART, PBS NEWSHOUR WEEKEND ANCHOR:

In the United States, nearly 30,000 deaths a year can be attributed to the abuse of heroin and prescription painkillers. Opioids like OxyContin, Vicodin, Percocet and Methadone. This epidemic in part was due to the surge in prescriptions being written over the last two decades.

However, a new analysis reveals that for each of the last three years, prescriptions are being written for opioids decline.

To discuss the implications of this, I'm joined from Washington, D.C., by Sabrina Tavernise of "The New York Times".

Sabrina, you've been reporting about this and writing about this for "The Times". What has contributed to this decline?