Final answer:
Prescription drug addiction has led to more fatal overdoses than illegal drugs due to the opioid crisis that began in the 1990s with the rise of addictive opioid prescriptions and subsequent shift to cheaper alternatives like heroin and synthetic opioids.
Step-by-step explanation:
Fatal overdoses caused by addiction to prescription drugs exceed those caused by illegal drugs such as heroin and street opiates. The crisis began in the 1990s when highly addictive opioid drugs like OxyContin were mass-marketed with misleading claims about their addictiveness. As opioid prescriptions rose dramatically, so did misuse, addiction, and overdoses. Eventually, prescription opioids became more difficult and expensive to obtain, leading many individuals to turn to cheaper alternatives such as heroin and synthetic opioids like Fentanyl, which further fueled the overdose crisis. By 2014, drug overdoses surpassed motor vehicle crashes as the leading cause of accidental death, highlighting the severity of the opioid epidemic.