Marijuana is far safer than alcohol, tobacco and multiple other illicit substances, researchers say, and strict, legal regulation of cannabis might be a more reasonable approach than current prohibitions.
Those are the findings of a new report published in Scientific Reports that compares the lethality of the recreational use of 10 common drugs, including marijuana, alcohol, tobacco, heroin, cocaine, ecstasy, methamphetamine, diazepam, amphetamine and methadone.
Researchers found that marijuana has the lowest risk of mortality and is safer than the commonly used alcohol and tobacco as well as the rest of the drugs in the study. They determined the risk of mortality by comparing the lethal dose of each substance with a commonly used amount of each substance.
The finding that marijuana has the lowest risk when compared with the other drugs is not surprising -- previous research had found that marijuana is a substantially safer recreational drug than other commonly used recreational drugs examined in this study. That finding stands in stark contrast to the lethal risk of alcohol, which the researchers found to be potentially more deadly than heroin.
Marijuana is so much less risky than alcohol and tobacco that the researchers say their results point toward developing policies that prioritize managing the risks associated with alcohol and tobacco, rather than the illicit drugs in the study. Further, the low risk of cannabis use suggests government should use "a strict legal regulatory approach rather than the current prohibition approach" to manage the substance, the researchers write.
Many world governments, including the United States, tend to have more restrictive policies around drugs such as marijuana than they do for alcohol and tobacco. The researchers note that their results confirm that the risk of cannabis "may have been overestimated in the past" and that the risk of alcohol "may have been commonly underestimated."
Legislation around illicit substances often have a "lack of scientific basis," the researchers say, and that's a point that is reflected in U.S. drug laws.
Under the Controlled Substances Act, the U.S. has five "schedules" for drugs and chemicals that can be used to make drugs. Schedule I is reserved for drugs that the Drug Enforcement Administration considers to have the highest potential for abuse and are the "most dangerous." Marijuana has been classified as Schedule I for decades, along with other substances like heroin and LSD. Cocaine is Schedule II. Alcohol and tobacco are exempted from the CSA.
But if science dictated drug policy, where would alcohol and tobacco be placed in the CSA?
"Of course alcohol and tobacco would be Schedule I," said Mark Kleiman, professor of drug policy and criminal justice at New York University and co-author of Marijuana Legalization: What Everyone Needs To Know.
"The whole scheduling system should be scrapped and replaced with something with more dimensions," Kleiman said, but he added that common reforms to drug policy can also come with problems.
Decriminalization, while good at reducing criminal punishment for nonviolent drug users, can still leave the drug supply in criminal hands, Kleiman said. And while legalization is less of a "kludge" than decriminalization, it's too early to tell if it is the most effective, at least with regard to marijuana, Kleiman explained. Four states, as well as Washington, D.C., have legalized recreational cannabis, and retail marijuana has been for sale for only a year in Colorado and Washington. Additionally, 23 states have legalized marijuana for medical purposes.
"For most currently prohibited drugs -- except cannabis and the hallucinogens -- it looks like smarter prohibition [is the answer]: less enforcement, more concentrated on bad illicit-market side-effects than on suppressing use, but sufficient to prevent flagrant open dealing," Kleiman said.
While marijuana may be safer than alcohol and tobacco, all of them have potential risks.
From heart disease to liver disease to elevated cancer risks, excessive alcohol consumption can indeed be devastating to a person's overall health. According to the Centers for Disease Control and Prevention, there are roughly 88,000 deaths attributable to alcohol use each year in the United States. In 2006, the CDC reported that there were 1.2 million emergency room visits and 2.7 million physician office visits due to excessive alcohol use.
Similarly, there's a laundry list of well-documented adverse health effects related to tobacco use, which harms nearly every organ in the body and causes the deaths of almost 480,000 people in the U.S. annually.
Of course, marijuana is not harmless either. Excessive use can lead to respiratory discomfort, although the drug itself has not been linked to lung damage. Studies have also shown cannabis can be addictive, however much less addictive than alcohol and even less than caffeine. That's not to say that marijuana can't be habit-forming: Between 4 and 9 percent of regular pot users can develop dependence on the drug, according to a frequently cited survey supported by the National Institute on Drug Abuse. That's compared with about 15 percent of drinkers who develop a dependence for alcohol.
Among people prone to the development of psychosis, research has shown that smoking pot can lead to an earlier onset of psychosis among those prone to the disorder. And there's understandable concern about adolescent marijuana use and its effects on the developing brain.
Still, in what is likely thousands of years of human consumption, there have been no documented deaths as a result of marijuana overdose. According to a 1988 ruling from the DEA, a marijuana user would have to consume 20,000 to 40,000 times the amount of THC in a joint to be at risk of a fatal dose.