Until the 1960s, when methadone was introduced to help heroin addicts overcome the painful symptoms of drug withdrawal, treatment for opioid addiction mainly involved quitting "cold turkey." Advances in the understanding of how opioids affect the central nervous system and body have led to more effective treatments that often combine medication with behavioral therapy and family support to promote long-lasting healing and recovery. There is hope for people addicted to opioids, although many experts feel that more treatment centers and education are needed. Opioids are psychoactive drugs derived from the opium poppy, such as heroin or morphine, or synthetic versions that mimic their effects, such as fentanyl or oxycodone. The series Opioid Education examines various aspects of opioid use and treatment in the United States and the rest of the world. The purpose of this series is to provide young readers with a greater understanding of the ongoing opioid crisis.