Cannabis Not in Fact Medicinal - Scientists Report

I just thought it worth reproducing these stories from several newspapers, today (27th November 2015) detailing new research which suggests that Skunk cannabis (the most widely available) is associated with physical damage to the human brain.   Those who say that if cannabis were on free sale, weaker types would be more readily available, seem to me to have a poor case.  Stronger brands of alcohol and tobacco continue to be highly popular, though both are legal and ���regulated���.

 

 

Daily Mail:

Strong cannabis does harm brain, researchers warn

By: Colin Fernandez

 

SMOKING super-strength cannabis can cause significant levels of brain damage, a study has shown. Researchers found that people who regularly took strong 'skunk' cannabis had signs of greater damage to the biggest 'tract' of white matter.

 

This area - the corpus callosum - carries signals between the brain's left and right sides. Damage to it can lead to mental illnesses and psychotic symptoms such as hallucinations, as well as slowing down the brain's activity.

 

The researchers say their findings demonstrate an 'urgent need' to educate the public, medical staff and policy makers about the risks of skunk - the most popular type of cannabis in the UK.

 

Skunk has high levels of a compound called Delta-9 tetrahydrocannabinol (THC) - which is key to giving smokers a high. Levels are about 20 per cent higher in skunk now than ten years ago, as cannabis growers create ever stronger strains of the plant to give a bigger buzz.

 

Dr Paola Dazzan, of the Institute of Psychiatry at King's College London, said: 'We found that frequent use of high-potency cannabis significantly affects the structure of white matter fibres in the brain, whether you have psychosis or not.

 

'This reflects a sliding scale where the more cannabis you smoke and the higher the potency, the worse the damage will be.' She said the damage to the corpus callosum was likely 'Urgent need for education' to make the brain less efficient because it slowed the flow of information across the brain.

 

The researchers studied 56 patients who reported having a psychotic incident for the first time and 43 healthy volunteers.

 

The healthy subjects had an average age of 27 and the psychotic patients an average age of 29. Half of the healthy volunteers smoked cannabis daily compared with 70 per cent of the psychotic patients. The scientists carried out MRI brain scans to assess levels of damage.

 

Dr Tiago Reis Marques, a senior research fellow at King's College London, said: 'The white matter damage was significantly greater among heavy users of high potency cannabis than in occasional or low potency users.' Dr Dazzan added: 'There is an urgent need to educate health professionals, the public and policy makers about the risks involved with cannabis use.

 

'When assessing cannabis use it is extremely important to gather information on how often and what type of cannabis is being used. These details can help quantify the risk of mental health problems and increase awareness on the type of damage these substances can do to the brain.' The authors write in Psychological Medicine: 'High-potency cannabis is replacing traditional herbal cannabis preparations in many European countries. Raising awareness about the risks of high-potency cannabis abuse seems therefore crucial.'

 

Daily Telegraph

 

'Skunk' cannabis damages key nerve fibres in the brain      

 

Powerful "skunk weed" cannabis causes significant damage to vital nerve fibres linking the two halves of the brain, a study has found.

 

The damage occurs in the corpus callosum, the structure that allows communication between the left and right hemispheres. Higher consumption of the drug caused more harm, according to the evidence. Its effect on users, and connection with psychosis - associated with strong forms of cannabis - remains unclear.

 

Dr Paola Dazzan, of King's College London, said there was an "urgent need" to educate health professionals, the public and policymakers about the risks associated with cannabis use. The study is published in the journal Psychological Medicine.

 

The Guardian

 

High-strength cannabis 'may damage brain'     

By: Ian Sample

 

Strong cannabis may damage nerve fibres that handle the flow of messages across the two halves of the brain, scientists say.

 

Scans of people who regularly smoked a skunk-like form of the drug revealed differences in the corpus callosum, the bundle of fibres connecting the hemispheres. The changes were not seen in non-users or those who smoked less potent forms. The study is thought to be the first to look at the effects of cannabis potency on brain structure. Paola Dazzan, a neurobiologist at King's College London, said the effects appeared to be linked to the level of active ingredient - THC - in the cannabis.

 

The corpus callosum - the brain's largest white matter structure - is rich in cannabinoid receptors, on which THC acts. In the study, reported in the journal Psychological Medicine, it was found that daily users of high-potency cannabis had a slightly greater "mean diffusivity" - by about 2% - in the corpus callosum.

 

Dazzan said: "That reflects a problem in the white matter that ... makes it less efficient. We don't know exactly what it means for the person, but it suggests there is less efficient transfer of information." The study does not confirm that high levels of THC in cannabis cause changes to white matter and it may be that people with damaged white matter are more likely to smoke skunk in the first place.

 

But even with the uncertainty, Dazzan urged users and public health workers to change how they think about the drug.

 

"When it comes to alcohol, we are used to thinking about how much people drink, and whether they are drinking wine, beer, or whisky," she said. "We should think of cannabis in a similar way - in terms of THC and the different contents cannabis can have - and potentially the effects on health will be different."

 

 

The Sun

 

SKUNK WRECKS BRAINS     

Drug risk exposed

By: NICK McDERMOTT

 

SMOKING "skunk" cannabis causes brain damage, scientists have warned. MRI scans on frequent users found the drug permanently altered their brain structure.

 

Experts fear the changes may have a long-term impact on their thinking power. "Skunk" is four times more potent than normal cannabis, and is the most commonly used form.

 

Researchers at King's College London looked at 99 adults, around half of whom smoked dope.

 

They found skunk users had the highest levels of brain damage. Dr Paola Dazzan, of the King's Institute of Psychiatry, Psychology and Neuroscience, said: "We found that frequent use of high potency cannabis significantly affects the structure of white matter fibres in the brain.

 

"The more cannabis you smoke and the higher the potency, the Danger ...worse the damage. This could reduce cognitive function (brain power)." It is reckoned that in England one in 16 adults have smoked cannabis in the last year.

 

A World Health Organisation report last year concluded regularly smoking cannabis doubles the risk of serious mental health problems.

 

The Times

 

Smoking skunk can cause brain damage    

By: Oliver Moody

 

Smoking skunk or other strong varieties of cannabis can cause brain damage similar to the effects of concussion, a study suggests.

 

The potency of the drug has risen consistently over the past two decades, leaving frequent users at an elevated risk of psychosis and subtler mental health problems.

 

Brain scans show that the highstrength cannabis that is increasingly common in the UK does more harm to the "white matter" connecting different parts of the brain than weaker strains.

 

Paola Dazzan, reader in the neurobiology of psychosis at King's College London, said that the region was the mind's traffic interchange, a tangle of highways carrying crucial instructions from one hemisphere to the other.

 

She and her colleagues used magnetic scanners called tractographs to examine the brain structure in 99 southeast Londoners, 59 of whom used cannabis regularly and 56 of whom had recently reported their first psychotic episode. They found that people who smoked more powerful varieties of cannabis tended to have more damage to their white matter, regardless of whether or not they had psychosis.

 

Also known as the corpus callosum, this part of the brain is important for the smooth running of a wide variety of cognitive functions and is the area believed to bear the brunt of concussion.

 

Two regions that seem to be particularly vulnerable to skunk contain motor fibres, which may contribute to hallucinations, poor co-ordination and warped sense perceptions if they are damaged. Although it is hard to link white matter structure to other specific mental problems, the changes associated with regular use of strong cannabis are likely to be gradual and general. "If you think of our brains, we've got left and right hemispheres, and the fibres that come from each part of the brain need to cross to the other part of the brain, and to do that they go through the corpus callosum," Dr Dazzan said.

 

Reliable data on the cannabis market are scarce, but a 2008 study for the Home Office found that it was increasingly dominated by homegrown herbal sinsemilla. This is about 15 per cent tetrahydrocannabinol (THC), the more damaging of the two active compounds in cannabis, compared with 9 per cent found in imported samples of the drug and 5 per cent found in resin.

 

Dr Dazzan said that THC was a neurotoxin that seemed to harm the brain's cannabinoid receptors. She called on health professionals to pay much more attention to the strength of cannabis used by their patients. "The main message is that the potency of the cannabis people use does matter greatly for the brain, whether they have psychosis or not," she said.

 

The study is published in the journal Psychological Medicine.