Despite a global increase in drug seizures and other efforts to curb supply, the global drug trade seems to be flourishing, and the so-called international “war” on drugs is failing, according to a new study, which found that even with seizures, prices are decreasing, and purity is increasing.

The researchers, from the University of British Columbia, looked at data from seven international government-funded surveillance systems, which tracked at least 10 years of drug price and purity, particularly for marijuana, cocaine, and opiates, such as heroin. They found that drug prices had gone down across the globe, while the purity of the drugs, and their seizures, had risen.

“By every metric, the war on drugs — which is estimated to have cost North Americans over the last 40 years over a trillion dollars — has really been hugely ineffective,” Dr. Evan Wood, senior author of the study and founder of the International Center for Science in Drug Policy, told The Star. “Drugs are more freely and easily available in our society than they’ve ever been.”

In the U.S.:

· Heroin prices dropped by 81 percent while the drug's purity rose 60 percent.

· Cocaine prices dropped 80 percent while the drug's purity rose 11 percent.

· Marijuana prices dropped 86 percent while the drug's purity rose 161 percent.

Europe saw similar trends, in which the prices of opiates dropped 74 percent while the prices of cocaine dropped 51 percent. In Australia, the prices of cocaine dropped by 14 percent while the prices of heroin and marijuana dropped by 49 percent.

Meanwhile, global seizures of certain drugs increased drastically. In the U.S., seizures of heroin and marijuana rose by 29 percent and 465 percent, respectively. By 2009, European seizures of heroin had risen 380 percent. “The data presented in this study suggest that the supply of opiates and cannabis have increased, given the increasing potency and decreasing prices of these illegal commodities,” the researchers concluded, according to a press release.

Although drug use may be considered a criminal justice issue, it’s also a public health issue, the researchers said. Heroin users who share needles, for example, could risk transmitting human immunodeficiency virus (HIV). The Centers for Disease Control and Prevention estimates at least 105 deaths every day from drug overdoses and another 6,748 emergency room visits for drug abuse.

Source: Werb D, Wood E, Kerr T, et al. The temporal relationship between drug supply indicators: an audit of international government surveillance systems. BMJ Open. 2013.