Using a novel method to measure the risk of mortality associated with the use of various legal and illegal drugs, scientists have confirmed what earlier studies have indicated: alcohol is the deadliest, while marijuana is the least risky.
According to the study, at the individual level, booze presents the highest risk of death, followed by nicotine, cocaine and heroin, suggesting the risks of alcohol consumption have likely been underestimated in the past. Marijuana was found to be significantly less deadly and sat at the other end of the spectrum, in agreement with previous research which has consistently ranked it as the safest recreational drug. While this may not be what governments want to hear, it highlights the need to use scientific evidence whilst creating policies regarding the use of licit and illicit drugs.
It seems that much of the world made up their mind a long time ago about the dangers of illegal substances. This, combined with the fact that it’s difficult to assess and classify the risk of drug abuse in people, means that few studies exist in which scientists have compared the dangers of different drugs. Furthermore, since illegal drug abuse is regarded as a bigger problem for society than using other known harmful substances, such as alcohol and even various prescription drugs, governments have tended to go for restrictive policies that are more often than not based on emotion and educated guesses.
Despite the difficulties, a few studies have attempted to assess the risks of various drugs, such as looking at how addictive and toxic they are in terms of acute and chronic use, but these have attracted criticism because some judgments may have been subjective rather than scientific. In an attempt to rectify these issues, scientists came up with a new risk assessment technique, called the “Margin of Exposure” (MOE) method. Put simply, this looks at the ratio between the dose which characterizes adverse effects and the amount that people typically use. The drugs they looked at were heroin, cannabis, nicotine, alcohol, methadone, amphetamine and MDMA.
http://www.iflscience.com/health-and-medicine/new-study-suggests-risks-marijuana-use-have-been-overestimated