Opioid addiction cost the nation more than $500 billion in 2015, according to a Council of Economic Advisers study released Monday. That figure is more than six times the $78.5 billion estimate from a private study in 2016. Opioids include both prescription drugs and illegal drugs, such as heroin. Oxycodone, codeine, hydrocodone, and morphine are some of the more commonly prescribed opioid painkillers. These painkillers can then become addictive because they create a feeling of euphoria.