Four percent of adults worldwide using cannabis: Lancet

New cannabis-like drugs could block pain without affecting brain, says study

Nearly four percent of adults around the world use cannabis, even though the drug raises many major health concerns, according to a paper published in The Lancet on Friday.

It cited figures from the UN Office on Drugs and Crime, which estimated that in 2006 there were 166 million users of cannabis aged from 15-64, or 3.9 percent of the world's population in this age category.

The drug is most used among young people in rich countries, led by the United States, Australia and New Zealand, followed by Europe, but appears to be becoming popular on a global scale, with use rising in low- and middle-income countries, it said.

The study, written by Australian professors Wayne Hall and Louisa Degenhardt, is an overview of published research into cannabis use and impacts.

Hall and Degenhardt say that, as a problem for public health, cannabis use "is probably modest" compared with the burden from alcohol, tobacco and other illegal drugs.

Even so, cannabis has a long list of suspected adverse health effects, they warn.

These include the risk of dependence, car accidents, impaired breathing, damaged , psychotic episodes and educational failure among teens who smoke the drug regularly.

Around nine percent of people who ever use cannabis become dependent on it, says the paper. By comparison, the risk of addiction for nicotine is 32 percent, 23 percent for heroin, 17 percent for cocaine and 15 percent for alcohol.

"Acute adverse effects of cannabis use include anxiety and panic in naive [first-time] users, and a probable increased risk of accidents if users drive while intoxicated," it says.

"Use during pregnancy could reduce birthweight, but does not seem to cause birth defects. Whether cannabis contributes to behavioural disorders in the offspring of women who smoked cannabis is uncertain."

Those who claim that cannabis is safer than smoking are also probably misguided.

Cannabis smoke contains many of the same cancer-causing chemicals as tobacco smoke, and some of them are in higher concentrations. Wheezing, coughing and bronchitis are commonly reported amongst cannabis smokers.

Evidence to support suspicions that cannabis causes cancer are inconclusive, though, because most frequent and long-term cannabis users also smoke tobacco.

Another area of concern is about so-called skunk -- extremely potent cannabis that derives from plants selected to have higher levels of tetrahydrocannabinol (THC), the drug's active ingredient.

Some evidence has emerged that levels of THC found in seized have risen in the past two decades, says the study.

"A high THC content can increase anxiety, depression and psychotic symptoms in naive users, while increasing the risk of dependence and psychotic symptoms if regular users do not titrate [measure out] their dose."

(c) 2009 AFP

Citation: Four percent of adults worldwide using cannabis: Lancet (2009, October 16) retrieved 19 August 2019 from
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Oct 16, 2009
Hall and Degenhardt say that, as a problem for public health, cannabis use "is probably modest" compared with the burden from alcohol, tobacco and other illegal drugs.

This being the case then to get a bigger bang for the buck, focus the time and money on the other more serious threats to health mentioned plus the over prescribed legal drugs.

Oct 16, 2009
You just stated that it's less dangerous to our health than alcohol, tobacco (legal drugs), and other (illegal) drugs. It has a lower dependency rate than alcohol (9% vs 15%, a significant difference) and has less social costs associated with it.

Why are we driving people to drink when there's a safer alternative? You don't even go into alternate consumption options such as vaporization. Only suggesting that smoking is unhealthy.

Oct 16, 2009
"Educational failure" may simply be a statist federal tyranny describing an individual who rejects their indoctrination.

As for the physical dangers, I recommend a low-cost vaporizer for anyone who takes cannabis regularly. Do not smoke cannabis if you can help it, especially with H1N1 making the rounds. A lung infection in a heavy, chronic smoker can be much more complicated, if not fatal.

And about going nuts: Well, let's just say the only thing you can bring out of you is what's in you already.

Oct 16, 2009
"It cited figures from the UN Office on Drugs and Crime"...this alone makes the whole article suspect. The UN is not known for diligence and accuracy in its research or data gathering.

Oct 16, 2009
They forgot to put up the sister study - "20% of adults worldwide lie about not using cannabis"...

Oct 17, 2009
They compare the risks of addiction, but not the percentage of usage. In the western world I wouldn't be surprised if 80% consumed alcohol and that has a whole range of negative cognitive and physical consequences.

Oct 18, 2009
News Flash: 4% of adults worldwide whom drive cars attempt to pass on the right instead of in the "passing lane" even though this raises many major health concerns.

From yours truly,
Who T.H. Cares

Oct 18, 2009
Speaking as an American only: I'm sure the criminal and legal ramifications of prohibition on Marijuana have caused much more damage to people in our society than the relatively minor health risks involved.

And this is to say nothing about the numbers of people who've turned to alcohol for recreational use instead of a healthier alternative.

In any case, the situation isn't going to go away like most think. Even the most educated of people do things that don't bode well with their well being. There simply is a segment of society that decides the risk of drugs, legal and illegal, are worth it for whatever reward they get. By continuing this prohibition we're only bringing the burden of it all on those who aren't involved. Let the users use and let the non-users get on with their lives.

Oct 19, 2009
The number of comments that reports about cannabis attract is very interesting. Could this be related to cannabis use ?

Oct 19, 2009
"anxiety and panic"

Has nothing to do with hob-nailed boot enforcement.

And, no, I've never used it.

Oct 25, 2009
I would have thought 4% was a bit low...

Dec 10, 2009
While I do think that alcohol is more dangerous, and nicotine is worse for you in the long run, the point is, it is still a drug that chemically changes your perception and cognitive abilities. I understand THC has valid medical uses. But ask yourself, are you using it recreationally or medicinally? If your answer is the former, then you aren't doing yourself, or society, a favor.

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