SEATTLE, Aug. 31 (UPI) -- Marijuana is the top illegal drug used worldwide, but doctor-prescribed painkillers such as Vicodin and Oxycontin are the deadliest, a U.S. researcher says.
Senior author Theo Voss of the Institute for Health Metrics and Evaluation at the University of Washington in Seattle and colleagues said marijuana beat cocaine, heroin, methamphetamine and hallucinogens when it comes to prevalence of users.