Clinical evidence indicating that marijuana use may be casually linked to incidences of schizophrenia or other psychological harms is not compelling, according to a scientific review published online by the journal Addiction.

Investigators at the University of Bristol, Department of Social Medicine assessed the potential health risks of cannabis, particularly whether use of the drug may be causally linked with mental illness.

Authors wrote: “We continue to take the view that the evidence that cannabis use causes schizophrenia is neither very new, nor by normal criteria, particularly compelling. … For example, our recent modeling suggests that we would need to prevent between 3000 and 5000 cases of heavy cannabis use among young men and women to prevent one case of schizophrenia, and that four or five times more young people would need to avoid light cannabis use to prevent a single schizophrenia case. … We conclude that the strongest evidence of a possible causal relation between cannabis use and schizophrenia emerged more than 20 years ago and that the strength of more recent evidence may have been overstated.”

In 2007, an analysis in the British medical journal The Lancet estimated that experimenting with marijuana could increase one’s risk of developing a psychotic illness later in life by some 40 percent. Following this report, Parliament in 2008 voted to reclassify marijuana as a Class B substance, making its possession punishable by up to five years in prison.

University of Bristol researchers also criticized Parliament’s reclassification of the drug, which took effect earlier this year. They concluded: “The only important possible benefit of prohibition is prevention of cannabis use. There is little or no evidence that it effectively achieves this benefit. Patterns of cannabis use in the population appear to be independent of the policy surrounding use, and criminalizing individual cannabis users does not appear to modify their use in a healthy way.”

Overall, investigators determined that marijuana’s most significant health risk was its association and reinforcement with tobacco smoking.

Will Brown kowtow to this current (and really bizarre) epoch of British media Reefer Madness or respect the ACDM’s logical and pragmatic recommendation not to increase the penalties for cannabis? Why does the British Home Office (and apparently the opposition Tory leader David Cameron as well) continue to pretend The Netherlands–and their ongoing, 35-year positive experience with controlled cannabis sales–does not occur just 95 miles away?

Of course British law enforcement groups want the increase in penalties, and subsequent arrests therein.

Cameron, who certainly has primary experience with cannabis (his incident at Eton is instructive, as is his waffling on just how late in life he has used cocaine) sounds like a typical, hypocritical and pandering anti-‘drug’ politician when he tells The Daily Telegraph, “There are all sorts of cannabis on the streets today. Skunk and super skunk are incredibly powerful and can lead to people having all sorts of mental health problems.”

The Daily Telegraph (April 3, 2008)

Gordon Brown is facing a dilemma over whether to overrule his own panel of experts and increase the penalties for being caught in possession of cannabis.

The Advisory Council on the Misuse of Drugs is understood to have decided at a private meeting that it will not recommend tightening the law on the drug.

The decision presents a potential embarrassment for the Prime Minister, who earlier this week said that he regarded cannabis use as not just illegal but also unacceptable.

It is understood that 20 out of the panel’s 23 experts decided on Wednesday that there was not sufficient new scientific evidence to justify a change.

If Mr. Brown decides to press ahead with reclassification, he will risk becoming only the second Prime Minister to over-rule the council, which is a statutory non-departmental public body dating from 1971.

The Conservatives said that the Government “need a long spell in rehab” over its apparent dithering over the whether to increase the penalties for possessing cannabis.

The Government reclassified cannabis as a Class C substance – dropping the penalty for possession from five to two years in jail – in 2004.

Since then it has reviewed the decision twice, in 2005 and 2008.

Critics say the decision to reclassify has unleashed a major public health problem with figures showing that abuse of cannabis putting 500 adults and children in hospital every week.

Conservative leader David Cameron said: “There are all sorts of cannabis on the streets today. Skunk and super skunk are incredibly powerful and can lead to people having all sorts of mental health problems.

“The Conservative Party has a very clear view that it should be class B. People have had enough of reviews and the Prime Minister should stop dithering and get on and make a decision.

“We need to have more treatment programmes, including residential programmes that take drug addicts and get them off drugs rather than giving them other opiates.”

Liberal Democrat Mayoral candidate Brian Paddick, who as police commander in Lambeth, south London urged officers to ignore cannabis possession in 2001, said the classification was irrelevant to young people.

He said: “No young person I know decides if they will smoke cannabis based on whether it’s a class B or class C drug. It’s time the Government stopped playing politics with cannabis and started preventing people from using it in the first place.”

The mental health charity Rethink, which gave evidence to the committee, said Mr. Brown should heed the committee’s advice.

Paul Corry, a spokesman, said: “Gordon Brown should put aside his personal views on cannabis and accept the fact that it does not make sense to reclassify.

“Use of the drug has gone down since it was downgraded in 2004 and research by Rethink shows that only 3 per cent of users would consider stopping on the grounds of illegality.”

The Association of Chief Police Officers said it backed a reclassification of cannabis.

A spokesman said: “The ACPO position on cannabis has been well articulated. We stand by the recommendation made to the Advisory Council on Misuse of Drugs that cannabis should be restored to the category of Class B drug.”

Mr. Brown ordered the committee to carry out the review of the 2004 decision to downgrade cannabis to a class C drug in one of his first acts on becoming Prime Minister last year.

The committee is understood to have concluded there was no need re-classify after new research found no evidence that rising cannabis use in the 1970s, 1980s and early 1990s had led to increases in schizophrenia.

This is despite many reports pointing to a links between super-strength skunk cannabis, which accounts for 80 per cent of street cannabis, and mental illnesses such as schizoprenia and psychosis.

The Home Office spokesman said the Government would make a decision when it received the advisory council’s recommendations.

She said: “Our message has always been that cannabis is an illegal and harmful drug that should not be taken.

“While evidence shows that cannabis use is falling across all age ranges, we are concerned about stronger strains of the drug.

“That is why we asked the independent Advisory Council on the Misuse of Drugs to undertake a review of cannabis classification.

“We tackle cannabis use through tough enforcement, education, prevention and treatment where necessary.”

For readers on this side of the pond who have not followed this story, “skunk” is the slang term British prohibitionists have chosen in their attempt to rebrand cannabis as this millennium’s most dangerous drug. (US authorities executed a similar game plan in the early 1900s when they successfully outlawed hemp by rebranding it “marijuana”.) For years now, British police and news reporters have blamed everything from psychosis and suicide to criminal acts like rape and murder on the after-effects of smoking “skunk,” aka allegedly super-potent pot.

Never mind that a recent study reported that so-called “skunk” only comprises a minute fraction of the UK’s marijuana market.

Never mind that teen use of cannabis in Great Britain recently fell to a record low.

Never mind that a legal pill containing 100 percent THC is available by a doctor’s prescription and that its side-effects do not include psychosis, suicide, rape, or murder.

And, most importantly, never mind that — to date — nobody in Britain or anywhere else on the planet is actually “injecting” the “main ingredient” in “skunk” (which, of course, is THC). Let’s not let facts get in the way of a good horror tale.

Of course, this pseudo-documentary — along with the recent rash of alarmist headlines — is all part of a concerted effort to push through PM Gordon Brown’s ill-conceived plan to recriminalize minor pot possession. And there’s no chance of government officials letting truth get in the way of that.