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.

In the months prior to the duo’s decision to call for the reclassification of cannabis — a move that increases the penalties for minor pot possession from a verbal warning to up to five years in jail — both politicians claimed that the potency of so-called British ‘skunk’ was skyrocketing out of control. Smith told the Commons that the strength of pot had increased “threefold” in recent years, while PM Brown told Reuters news wire, “[T]he cannabis on the streets is now of a lethal quality.”

Both implied that Parliament’s 2004 decision to downgrade pot possession to a verbal warning was responsible for the influx of supposed ‘triple-strength killer weed.’

Turns out Smith and Brown were full of it.

According to pot potency data collected by the UK’s Forensic Science Services and published by The Guardian newspaper, the average potency of THC in seized samples of British cannabis fell approximately 25 percent between 2004 and 2007.

Predictably, neither Smith nor Brown have issued any sort of public correction for their politically expedient, though thoroughly dishonest, remarks. Nor would one expect them to.

After all, for politicians, cops, and bureaucrats, lying about cannabis isn’t even considered lying — it’s simply viewed as part of the job. In fact, for the US Drug Czar, lying is actually mandated by law.

Of course, given the relative safety of adult cannabis use and given the utter failure of US criminal cannabis prohibition, it really can be no other way. Talking honestly about marijuana undermines federal drug policy so the only alternative for our elected officials is to lie — or say nothing at all. Troublingly, the leaders of both political parties have become adept at both.

Lest anyone think that science or reason guide modern cannabis policy, I present to you today’s announcement from British Home Secretary (and former pot smoker) Jacqui Smith calling on Parliament to increase pot penalties from a verbal warning — the current policy — to up to five years in jail.

Smith’s expected announcement (Watch the video here.) comes just days after British Prime Minister Gordon Brown — who has been afflicted with a severe case of ‘Reefer Madness’ since taking office last June — raved that consuming cannabis can be fatal, and that strict penalties on pot are necessary in order to “send a message” to young people that marijuana smoking is “unacceptable.”

Ironically, the Home Secretary’s formal announcement contradicts the official recommendations of Britain’s Advisory Panel on the Misuse of Drugs, which released its own report today finding that pot lacks the potential health risks of most other illicit drugs, and that its use is unlikely to trigger mental illnesses, such as schizophrenia.

It is the third time in six years that the Panel has demanded that legislators classify cannabis as a Class C ‘soft’ drug, with minor, if any, criminal penalties. Unlike Smith or Brown, the Advisory Panel consists of experts commissioned to evaluate and determine British drug policies — hence it’s hardly surprising that their findings would be totally disregarded by British bureaucrats.

For those readers who have not closely followed Britain’s ongoing pot policy debate, here’s a brief history lesson:

In January 2004, Parliament downgraded the legal classification of cannabis from a Class B drug (such as amphetamines or barbiturates) to a Class C drug (such as anabolic steroids) — thus allowing police to issue verbal warnings to minor pot offenders in lieu of arresting them. Since then, the following events have occurred:

One-third fewer Britons have been arrested for pot offenses;

Marijuana use by those age 16 to 20 years of age has fallen by 20 percent;

Fewer than ten percent of Britons now report using cannabis — the lowest percentage ever recorded.

In fact, the current policy has worked so well that the British Association of Chief Police Officers has announced that they will refuse to waste their time and resources arresting minor pot offenders — regardless of what Parliament decides.

So let’s review shall we. Gordon Brown wants to jail pot users to keep them from dying at the hands of weed — a stance so absurd that even the cops won’t go along with it. Home Secretary Jacqui Smith wants to jail pot users to keep them from losing their minds even though she herself smoked pot and is now one of the most powerful women in British politics. (Whether she is of sound mind remains debatable, I suppose.) The British Advisory Panel on the Misuse of Drugs thinks that Brown and Smith’s calls for reclassification are based on tabloid headlines in the Daily Mail rather than actual science, so they are dismissed as ‘know-nothings’ by the very same people who, quite literally, know nothing.

And that, my friends, is how we decide cannabis policy in 2008.

Any questions?

As always, the first casualty in war is truth — and nowhere is this more evident than in Great Britain, where Prime Minister Gordon Brown appears intent on recriminalizing cannabis over the vehement objections of his own scientific advisory panel of experts and even the police.

Hysteria Over Cannabis Getting In The Way Of Truth
via The Observer

First, cannabis remains the most commonly used illegal drug. But its use has been falling steadily since 2000, with no hint that this decline was affected by reclassification. Home Office statistics show that cannabis use by 16- to 24-year-olds has fallen by about 20 per cent since 2004. So, if we naively argue from correlations (the basis of so much of the evidence about harm), returning cannabis to B would be expected to increase its use.

Second, there is concern about the message that reclassification has sent. But there is no evidence that classification influences the attitude of young people to drugs. Amphetamines, cocaine and ecstasy are all runners-up to cannabis in the league table of popularity in this country – and they are all class A. Usage of cocaine has grown over the past eight years, as that of cannabis has declined.

Third, there is, quite rightly, a particular worry about young people. Yet the the government’s own figures show that only one 11-year-old in 150 has tried cannabis in the last year, while 4 per cent have sniffed glue and fully 21 per cent have drunk alcohol.

Read the full article here.

And speaking of hysteria, cannabis, and British PM Gordon Brown, the Prime Minister has recently begun claiming that pot is “lethal,” despite the well-known fact that a human overdose from weed is physically impossible.

Pot lethal?! Hardly.

Pot prohibition on the other hand…