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mercoledì 10 ottobre 2018
giovedì 26 luglio 2018
martedì 15 settembre 2015
giovedì 19 febbraio 2015
Cannabis: Promise, risk and controversy
Cannabis is bad for you, cannabis is good for you - confused?
That's not surprising. Complicated and controversial, cannabis is revealed by recent science to have a dual personality, with a dark side and a more positive one. Radio 4's PM programme is this week running a whole series on cannabis, and the debate surrounding it.
Key to understanding this strange plant are two of the ingredients that make it up, known by their initials as THC and CBD.
I asked Professor Val Curran of University College London to describe how they work and she came up a memorable answer:
"In a way, THC and CBD are a bit like yin and yang. The THC makes you stoned, but it can also make you anxious. It can also make you feel a bit psychotic, and it will seriously impair your memory.
"The other side of the yin/yang is CBD, which has almost the opposite effects. CBD calms you down, it has anti-psychotic properties and it also offsets the effects on memory, so that on CBD-containing cannabis you're less likely to forget what's going on."
So the first step to understanding cannabis is to realise how it can vary, how different types contain very different quantities of these polar opposites, with dramatically different outcomes.
Changing risks
The weed so familiar to many of my generation was characterised by a relatively balanced amount of THC and CBD.
Today, the vast majority of cannabis on sale on the streets is unrecognisably stronger.
Known as skunk, it contains a far higher proportion of THC - as much as 15% - which produces a much more powerful high, making it more appealing for users.
But, at the same time, because it hardly contains any of the CBD that might lessen its effects, the risks are correspondingly greater.
Prof Curran is among those worried about its potency.
"What concerns me is that on this high-THC skunk, people will experience more memory problems, which could affect how well they do at school. And in terms of addiction, 10% of people who use it will become addicted to the drug."
According to a study by two researchers at UCL, Dr Tom Freeman and Dr Adam Winstock, the strongest cannabis increases the risk of addiction, along with memory loss and paranoia.
And in a trial to explore ways of helping addicts, they are giving drug users medication based on cannabis itself. The hope is that administering doses of CBD, the more benign ingredient of cannabis, might make it easier for habitual users to wean themselves off the lure of the more potent element, THC.
Dr Freeman told the BBC: "We think that CBD can reverse long-term changes which happen when you smoke cannabis repeatedly, and in people who smoke a lot of cannabis it'll help them quit.
"It blocks the effects of THC and it reduces anxiety and paranoia. If this trial is successful, then we will have found the first effective drug treatment for cannabis dependence."
Meanwhile, new evidence has surfaced that will stir the long-running debate over whether - or to what extent - cannabis can trigger psychosis.
New research published this week in the Lancet Psychiatry suggests a connection, a finding which is most relevant to people already vulnerable to mental illness.
The study, conducted in south London, involved some 800 people - about half of them users, the rest not.
One of the authors, Prof Sir Robin Murray of King's College London, says it's clear that regular use of highly potent skunk has a real impact.
"We found that smoking cannabis, particularly of the high-potency forms, was associated with an increased risk.
"If you smoke high-potency skunk at all, then you are three times more likely to be psychotic. If you smoke high-potency cannabis every day, you are five times more likely to be psychotic."
Cautious optimism
And at this point we come back to that yin and yang of cannabis. While this new research finds that the strongest cannabis, laden with THC, can be linked to psychosis, it turns out that the gentler twin, CBD, might possibly be useful in treating it.
Prof Murray, though cautious, highlights recent studies.
"If you give THC to normal volunteers, you can make them psychotic, but if you pre-treat them with CBD, you can prevent that happening.
"So this made us think - would it be possible to actually treat psychosis with CBD? So there's one encouraging study, which suggests that CBD is useful in the treatment of psychosis, but it's still very early days yet."
So running in parallel with concerns about cannabis is another world of optimism about its uses.
In Colorado, there is much excitement about a medication called Charlotte's Web, derived from cannabis and named after a girl who took it as a treatment for her epilepsy.
Such is the potential of what's seen as a wonder drug that the Mattison family sold up their business in Tennessee and moved to Colorado purely so that their daughter Millie, who's two years old and epileptic, could receive Charlotte's Web.
Her seizures, soon after birth, were so severe that she had been given very little chance of surviving.
But her mother Nicole told me that the drug proved immediately beneficial, transforming Millie's life almost at a stroke.
"It's miraculous. The first time we gave her oil, within 15 minutes her eyes were open, and I almost felt like I was in a movie.
"It was crazy, you wouldn't believe it unless you saw it."
Here in the UK, the only legal medicine derived from cannabis is for sufferers of multiple sclerosis (MS), a product called Sativex made by GW Pharma.
But now the company, the only one with a licence to grow cannabis in the UK, has developed another formulation which is being tested to treat epileptic conditions like Millie's.
Early days
The trial, with 80 patients, is now in its second stage and is being run by the University of Edinburgh.
The scientist in charge of the process, Dr Richard Chin, says that so far the results look promising, not just to control seizures but - remarkably - to prevent them as well.
"One of the interesting things about cannabidiol (CBD) is that it shows not just anti-seizure effects, but it also curiously seems to have an effect on cognitive and behavioural problems, which are very highly represented in people with epilepsy.
"So it doesn't seem, on preliminary data, as if it's just an anti-seizure medication. It may actually be an anti-epilepsy medication in its wider sense, and what I would hope is that it may open up a completely new avenue of treatment options for patients with epilepsy."
For thousands of years cannabis was used medically. But only now is research revealing why that's possible and how it can be put to best use.
These are relatively early days but, on the horizon, researchers see potential for the CBD in cannabis to help with everything from easing the pain of cancer to tackling autism.
At the same time, science is also unpicking the full implications of the potent stuff being dealt on our streets.
BBC: Cannabis: Promise, risk and controversy
That's not surprising. Complicated and controversial, cannabis is revealed by recent science to have a dual personality, with a dark side and a more positive one. Radio 4's PM programme is this week running a whole series on cannabis, and the debate surrounding it.
Key to understanding this strange plant are two of the ingredients that make it up, known by their initials as THC and CBD.
I asked Professor Val Curran of University College London to describe how they work and she came up a memorable answer:
"In a way, THC and CBD are a bit like yin and yang. The THC makes you stoned, but it can also make you anxious. It can also make you feel a bit psychotic, and it will seriously impair your memory.
"The other side of the yin/yang is CBD, which has almost the opposite effects. CBD calms you down, it has anti-psychotic properties and it also offsets the effects on memory, so that on CBD-containing cannabis you're less likely to forget what's going on."
So the first step to understanding cannabis is to realise how it can vary, how different types contain very different quantities of these polar opposites, with dramatically different outcomes.
Changing risks
The weed so familiar to many of my generation was characterised by a relatively balanced amount of THC and CBD.
Today, the vast majority of cannabis on sale on the streets is unrecognisably stronger.
Known as skunk, it contains a far higher proportion of THC - as much as 15% - which produces a much more powerful high, making it more appealing for users.
But, at the same time, because it hardly contains any of the CBD that might lessen its effects, the risks are correspondingly greater.
Prof Curran is among those worried about its potency.
"What concerns me is that on this high-THC skunk, people will experience more memory problems, which could affect how well they do at school. And in terms of addiction, 10% of people who use it will become addicted to the drug."
According to a study by two researchers at UCL, Dr Tom Freeman and Dr Adam Winstock, the strongest cannabis increases the risk of addiction, along with memory loss and paranoia.
And in a trial to explore ways of helping addicts, they are giving drug users medication based on cannabis itself. The hope is that administering doses of CBD, the more benign ingredient of cannabis, might make it easier for habitual users to wean themselves off the lure of the more potent element, THC.
Dr Freeman told the BBC: "We think that CBD can reverse long-term changes which happen when you smoke cannabis repeatedly, and in people who smoke a lot of cannabis it'll help them quit.
"It blocks the effects of THC and it reduces anxiety and paranoia. If this trial is successful, then we will have found the first effective drug treatment for cannabis dependence."Meanwhile, new evidence has surfaced that will stir the long-running debate over whether - or to what extent - cannabis can trigger psychosis.
New research published this week in the Lancet Psychiatry suggests a connection, a finding which is most relevant to people already vulnerable to mental illness.
The study, conducted in south London, involved some 800 people - about half of them users, the rest not.
One of the authors, Prof Sir Robin Murray of King's College London, says it's clear that regular use of highly potent skunk has a real impact.
"We found that smoking cannabis, particularly of the high-potency forms, was associated with an increased risk.
"If you smoke high-potency skunk at all, then you are three times more likely to be psychotic. If you smoke high-potency cannabis every day, you are five times more likely to be psychotic."
Cautious optimism
And at this point we come back to that yin and yang of cannabis. While this new research finds that the strongest cannabis, laden with THC, can be linked to psychosis, it turns out that the gentler twin, CBD, might possibly be useful in treating it.
Prof Murray, though cautious, highlights recent studies.
"If you give THC to normal volunteers, you can make them psychotic, but if you pre-treat them with CBD, you can prevent that happening.
"So this made us think - would it be possible to actually treat psychosis with CBD? So there's one encouraging study, which suggests that CBD is useful in the treatment of psychosis, but it's still very early days yet."
So running in parallel with concerns about cannabis is another world of optimism about its uses.
Such is the potential of what's seen as a wonder drug that the Mattison family sold up their business in Tennessee and moved to Colorado purely so that their daughter Millie, who's two years old and epileptic, could receive Charlotte's Web.
Her seizures, soon after birth, were so severe that she had been given very little chance of surviving.
But her mother Nicole told me that the drug proved immediately beneficial, transforming Millie's life almost at a stroke.
"It's miraculous. The first time we gave her oil, within 15 minutes her eyes were open, and I almost felt like I was in a movie.
"It was crazy, you wouldn't believe it unless you saw it."
Here in the UK, the only legal medicine derived from cannabis is for sufferers of multiple sclerosis (MS), a product called Sativex made by GW Pharma.
But now the company, the only one with a licence to grow cannabis in the UK, has developed another formulation which is being tested to treat epileptic conditions like Millie's.
Early days
The trial, with 80 patients, is now in its second stage and is being run by the University of Edinburgh.
The scientist in charge of the process, Dr Richard Chin, says that so far the results look promising, not just to control seizures but - remarkably - to prevent them as well.
"One of the interesting things about cannabidiol (CBD) is that it shows not just anti-seizure effects, but it also curiously seems to have an effect on cognitive and behavioural problems, which are very highly represented in people with epilepsy.
"So it doesn't seem, on preliminary data, as if it's just an anti-seizure medication. It may actually be an anti-epilepsy medication in its wider sense, and what I would hope is that it may open up a completely new avenue of treatment options for patients with epilepsy."
For thousands of years cannabis was used medically. But only now is research revealing why that's possible and how it can be put to best use.
These are relatively early days but, on the horizon, researchers see potential for the CBD in cannabis to help with everything from easing the pain of cancer to tackling autism.
At the same time, science is also unpicking the full implications of the potent stuff being dealt on our streets.
BBC: Cannabis: Promise, risk and controversy
martedì 20 novembre 2012
US marijuana legalisation fuels Mexico drugs war debate
Will Mexico's drug cartels see a drop in profits as a result of changes in the US?
There are still complex questions about creating a regulatory framework for the production and distribution of the drug, which may take at least another year.
Needless to say, such a move puts the two states on a legal collision course with the federal government and its drug enforcement policies. But Dr Kilmer believes it is a mistake to view the Obama administration as a single entity in this regard.
"At this point no-one knows how the federal government is going to respond to these two states. But it's important that we don't think of it as a homogenous actor."
The Drug Enforcement Administration (DEA), the US Attorney-General's office and the Internal Revenue Service (IRS) all have a degree of jurisdiction, and discretion, over these issues, Dr Kilmer points out.
Use of force Meanwhile, thousands of kilometres away, in a "smoke shop" in Mexico City, the news of Colorado and Washington's decision has been warmly welcomed. Surrounded by glass cabinets full of expensive-looking vaporiser, the proprietor tells me that many of his customers are hoping for a similar law in Mexico.
"People don't want to contribute to the drug cartels' profits any more and I've sold a lot of copies of this recently," he says, holding up a book called The Ecological Cultivation of Cannabis.
"We need to ask if it makes sense to carry on with this full-frontal military campaign which has generated so much destruction and death in our country in order to impede the entrance into the United States of a substance which is now permitted and regulated."
Mr Belauzaran does not necessarily expect his measure to pass in this legislative session. But what is important, he says, is the new discourse on the issue.
In some parts of the US and Mexican media, the decision in Washington state and Colorado has been called a "game-changer" in the bilateral relationship between Mexico and the United States on the war on drugs.
Both the outgoing administration and the incoming one in Mexico have indicated that they expect things to develop with respect to marijuana during President Obama's second term.
Hosting several central American leaders recently, Mexican President Felipe Calderon said the decision in the US was a "change in paradigm" on drug consumption. He called for the United Nations and the Organisation of American States to help clarify the situation.
The new government went even further.
"Obviously, we can't handle a product that is illegal in Mexico, trying to stop its transfer to the United States, when in the United States - at least in part of the United States - it now has a different status," Luis Videgaray, President-elect Enrique Pena Nieto's top adviser, told journalists.
But it is not just in Mexico that the debate on marijuana is shifting. Uruguay too, under left-wing President Jose Mujica, is moving to put the state in charge of regulating the cultivation and consumption of legal cannabis.
Continent-wide, there are obviously many discussions still to be had.
Advocates and opponents disagree about the extent to which legalisation of marijuana would hurt the drug cartels' profits - some quoting figures in the billions, others in the mere tens of millions. And there is still a long way to go before President Obama formulates a coherent response to the voters' decision in the two states.
But amid the smoke and mirrors, one thing seems clear: when it comes to marijuana in the Americas, the seeds of change have been sown.
US marijuana legalisation fuels Mexico drugs war debate
Earlier this month, two
US states voted to legalise, regulate and tax marijuana. The BBC's Will
Grant in Mexico City looks at what this shift in stance could mean for
Mexico and its fight against the drug gangs.
On the day voters in Washington state chose to re-elect
President Barack Obama, they also chose to legalise the recreational use
of marijuana. Over the Rockies in Colorado, it was a similar story.
"What happened in Colorado and
Washington was truly revolutionary," says Beau Kilmer, the co-director
of the Rand Drug Policy Research Centre in California. "No modern
country has ever removed the prohibition on the production and
distribution of marijuana for non-medical purposes."
When the measure comes into effect in Colorado in early
December, it will be legal to possess 1oz (28g) of marijuana if you are
over 21; it will be legal to grow up to six marijuana plants in your
house; and it will be legal to give away up to 1oz. There are still complex questions about creating a regulatory framework for the production and distribution of the drug, which may take at least another year.
Needless to say, such a move puts the two states on a legal collision course with the federal government and its drug enforcement policies. But Dr Kilmer believes it is a mistake to view the Obama administration as a single entity in this regard.
"At this point no-one knows how the federal government is going to respond to these two states. But it's important that we don't think of it as a homogenous actor."
The Drug Enforcement Administration (DEA), the US Attorney-General's office and the Internal Revenue Service (IRS) all have a degree of jurisdiction, and discretion, over these issues, Dr Kilmer points out.
Use of force Meanwhile, thousands of kilometres away, in a "smoke shop" in Mexico City, the news of Colorado and Washington's decision has been warmly welcomed. Surrounded by glass cabinets full of expensive-looking vaporiser, the proprietor tells me that many of his customers are hoping for a similar law in Mexico.
"People don't want to contribute to the drug cartels' profits any more and I've sold a lot of copies of this recently," he says, holding up a book called The Ecological Cultivation of Cannabis.
The man in Mexico currently leading the charge
to change the law is left-wing politician Fernando Belauzaran. He has
introduced a bill in Congress along similar lines to the one in
Colorado, which would bring marijuana under the same regulation as
alcohol.
"What has happened in the US has moved things forward,
because this debate is crucial," Mr Belauzaran told the BBC on the day
he formally presented the proposal. "We need to ask if it makes sense to carry on with this full-frontal military campaign which has generated so much destruction and death in our country in order to impede the entrance into the United States of a substance which is now permitted and regulated."
Mr Belauzaran does not necessarily expect his measure to pass in this legislative session. But what is important, he says, is the new discourse on the issue.
In some parts of the US and Mexican media, the decision in Washington state and Colorado has been called a "game-changer" in the bilateral relationship between Mexico and the United States on the war on drugs.
Both the outgoing administration and the incoming one in Mexico have indicated that they expect things to develop with respect to marijuana during President Obama's second term.
Hosting several central American leaders recently, Mexican President Felipe Calderon said the decision in the US was a "change in paradigm" on drug consumption. He called for the United Nations and the Organisation of American States to help clarify the situation.
The new government went even further.
"Obviously, we can't handle a product that is illegal in Mexico, trying to stop its transfer to the United States, when in the United States - at least in part of the United States - it now has a different status," Luis Videgaray, President-elect Enrique Pena Nieto's top adviser, told journalists.
But it is not just in Mexico that the debate on marijuana is shifting. Uruguay too, under left-wing President Jose Mujica, is moving to put the state in charge of regulating the cultivation and consumption of legal cannabis.
Continent-wide, there are obviously many discussions still to be had.
Advocates and opponents disagree about the extent to which legalisation of marijuana would hurt the drug cartels' profits - some quoting figures in the billions, others in the mere tens of millions. And there is still a long way to go before President Obama formulates a coherent response to the voters' decision in the two states.
But amid the smoke and mirrors, one thing seems clear: when it comes to marijuana in the Americas, the seeds of change have been sown.
US marijuana legalisation fuels Mexico drugs war debate
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