news-en

IACM-Bulletin of 25 November 2007in English..

IF YOU ARE INTERESTED IN OTHER NEWS AROUND

AND ABOUT CANNABIS VISIT.. http://www.newscientist.com/hottopics/marijuana/marijuana.jsp

Science: Moderate cannabis use not harmful to the brain of
adolescents, Magnetic Resonance Imaging study finds

Researchers of the Nathan S. Kline Institute for Psychiatric
Research and the New York University School of Medicine
scanned the brains of 10 individuals who were frequent cannabis
users in adolescence and 10 control subjects with advanced
Magnetic Resonance Imaging (MRI) methods. They found no
"evidence of cerebral atrophy or loss of white matter integrity"
and concluded that "frequent cannabis use is unlikely to be
neurotoxic to the normal developing brain."

The former cannabis users were now aged 18 to 27 years and
had used cannabis between daily to 2-3 times weekly for one or
more years during adolescence, but were currently abstinent.
They were compared to subjects of similar age and sex who
never used cannabis. Measurements were obtained of whole
brain and certain brain areas, which are most often related to
psychotic experiences and memory.

Scientists noted, that their "data are preliminary and need
replication with larger numbers of subjects, although they do
have implications for refuting the hypothesis that cannabis alone
can cause a psychiatric disturbance such as schizophrenia by
directly producing brain pathology."

The article is available for download at
http://www.harmreductionjournal.com/content/3/1/17

USA: Medicinal drug agency FDA looses credibility after a
statement on the medical value of cannabis

In a statement issued on 20 April the US medicinal drug agency
FDA (Food and Drug Administration) said that "no sound
scientific studies supported medical use of marijuana for
treatment in the United States, and no animal or human data
supported the safety or efficacy of marijuana for general medical
use."

Many commentators in the media noted that the FDA lost
credibility by this move. The New York Times reported on the
issue as follows. "The Bush administration's habit of politicizing
its scientific agencies was on display again this week when the
Food and Drug Administration, for no compelling reason,
unexpectedly issued a brief, poorly documented statement
disputing the therapeutic value of marijuana. The statement was
described as a response to numerous inquiries from Capitol Hill,
but its likely intent was to buttress a crackdown on people who
smoke marijuana for medical purposes and to counteract state
efforts to legalize the practice. (…) Ordinarily, when the F.D.A.
addresses a thorny issue, it convenes a panel of experts who
wade through the latest evidence and then render an opinion as
to whether a substance is safe and effective to use. This time the
agency simply issued a skimpy one-page statement asserting that
'no sound scientific studies' supported the medical use of
marijuana."

The British journal Economist wrote: "If Cannabis were
unknown, and bioprospectors were suddenly to find it in some
remote mountain crevice, its discovery would no doubt be hailed
as a medical breakthrough. Scientists would praise its potential
for treating everything from pain to cancer, and marvel at its rich
pharmacopoeia—many of whose chemicals mimic vital
molecules in the human body. In reality, cannabis has been with
humanity for thousands of years and is considered by many
governments (notably America's) to be a dangerous drug
without utility." The article said that the FDA statement lacks
"common sense".

Dr. Daniele Piomelli, a professor of pharmacology at the
University of California, was cited by the New York Times that
he had "never met a scientist who would say that marijuana is
either dangerous or useless." Studies clearly show that marijuana
has some benefits for some patients, Dr. Piomelli said. "We all
agree on that."

(Sources: New York Times of 21 and 22 April 2006, The
Economist of 27 April 2006, www.fda.gov)

Editors note>> the study below would have been done with smokers of pure cannabis. Not mixed with tobacco as is common in Europe.

NEWSScience: Cannabis smoking does not cause cancer according to
a case-control study

According to a case-control study by Dr. Donald Tashkin and
his colleagues of the University of California in Los Angeles even
heavy and longterm smoking of cannabis is not associated with
lung cancer and other types of upper aerodigestive tract cancers.
The results were presented on 26 June at the annual conference
of the International Cannabinoid Research Society (ICRS).

The study included 1,209 residents of Los Angeles aged 18-59
with cancer (611 lung, 403 oral/pharyngeal, 90 laryngeal, and
108 esophageal). Interviewers collected lifetime histories of
cannabis, tobacco, alcohol and other drug use, and data on
other factors that may influence cancer risk, including diet,
occupational exposures, and family history of cancer. Exposure
to cannabis was measured in joint years (1 joint year = 365
joints). The cancer patients were compared to 1,040 cancer-
free controls. Among the controls 46 per cent had never used
cannabis, 31 per cent had used it for less than one joint year, 12
per cent for 10-30 joint years, 2 per cent for 30-60 joint years,
and 3 per cent for more than 60 joint years.

Compared with subjects who had used less than one joint year,
the risk for lung cancer was 0.78 for 1-10 joint years, 0.74 for
10-30 joint years, 0.85 for 30-60 joint years, and 0.81 for more
than 60 joint years. A risk below 1.0 means that the risk for
cannabis users was slightly lower than for non-users. Similar
results were obtained for the other cancer sites. There was no
dose-response relationship of cancer risk, which means that
there was no increased risks for more intensive users. The data
on tobacco use, as expected, revealed a very potent effect and a
clear dose-response relationship.

(Source: Morgenstern H, et al. Marijuana use and cancers of the
lung and upper aerodigestive tract: results of a case-control
study. Presentation at the ICRS Conference on Cannabinoids,
24-27 June, Clearwater, USA)

***UK: No effect of law change on use
Contrary to claims that there has been an explosion in use since
the government decriminalized cannabis in January 2004, a new
study has found that the increase in regular use fell to just 0.5 per
cent in 2004, compared with an increase by 45 per cent at its
peak in 1998. "Our first indications are that [the change in the
law] has essentially had no effect at all in user levels of
cannabis," says Matthew Atha, director of the Independent
Drugs Monitoring Unit, which carried out the study. (Source:
The Observer of 27 March 2005)

Psychedelic medicine: Mind bending, health giving
26 February 2005
John Horgan is a freelance science writer based in Garrison, New York. His latest book, Rational Mysticism (Mariner Books), was published in paperback last year

JOHN HALPERN clearly remembers what made him change his mind about psychedelic drugs. It was the early 1990s and the young medical student at a hospital in Brooklyn, New York, was getting frustrated that he could not do more to help the alcoholics and addicts in his care. He sounded off to an older psychiatrist, who mentioned that LSD and related drugs had once been considered promising treatments for addiction. "I was so fascinated that I did all this research," Halpern recalls. "I was reading all these papers from the 60s and going, whoa, wait a minute! How come nobody's talking about this?"
More than a decade later, Halpern is now an associate director of substance abuse research at Harvard University's McLean Hospital and is at the forefront of a revival of research into psychedelic medicine. He recently received approval from the US Food and Drug Administration (FDA) to give late-stage cancer patients the psychedelic drug MDMA, also known as ecstasy. He is also laying the groundwork for testing LSD as a treatment for dreaded super-migraines known as cluster headaches.
And Halpern is not alone. Clinical trials of psychedelic drugs are planned or under way at numerous centres around the world for conditions ranging from anxiety to alcoholism. It may not be long before doctors are legally prescribing hallucinogens for the first time in decades. "There are medicines here that have been overlooked, that are fundamentally valuable," says Halpern.
These developments are a remarkable turnaround. Scientists first became interested in psychedelic drugs - also called hallucinogens because of their profound effect on perception - after Albert Hofmann, a chemist working for the Swiss pharmaceutical firm Sandoz, accidentally swallowed LSD in 1943. Hofmann's description of his experience, which he found both enchanting and terrifying, spurred scientific interest in LSD as well as naturally occurring compounds with similar effects: mescaline, the active ingredient of the peyote cactus; psilocybin, found in magic mushrooms; and DMT, from the Amazonian shamans' brew ayahuasca.
At first, many scientists called these drugs "psychotomimetics" because their effects appeared to mimic the symptoms of schizophrenia and other mental illnesses. However, many users rhapsodised about the life-changing insights they achieved during their experiences, so much so that in 1957, British psychiatrist Humphry Osmond proposed that the compounds be renamed "psychedelic", from the Greek for "mind-revealing". The term caught on, and psychiatrists started experimenting with the drugs as treatments for mental illness. By the mid-1960s, more than 1000 peer-reviewed papers had been published describing the treatment of more than 40,000 patients for schizophrenia, depression, alcoholism and other disorders.
A prominent member of this movement was Harvard psychologist Timothy Leary, who among other things tested whether psilocybin and LSD could be used to treat alcoholism and rehabilitate convicts. Although his studies were initially well received, Leary eventually lost his reputation - and his job - after he began touting psychedelics as a hotline to spiritual enlightenment. Leary's antics helped trigger a backlash, and by the late 1960s psychedelics had been outlawed in the US, Canada and Europe. Unsurprisingly, clinical research ground to a halt, partly because obtaining the necessary permits became much more difficult, but also because few researchers were willing to risk their reputations studying demonised substances.
But to some brave souls, psychedelic medicine never lost its allure. One of them is Rick Doblin, who in 1986 founded the Multidisciplinary Association for Psychedelic Studies (MAPS) in Sarasota, Florida, and who earned a doctorate from Harvard's Kennedy School of Government after writing a dissertation on the federal regulation of psychedelics. For nearly 20 years MAPS has lobbied the FDA and other government agencies to allow research on psychedelics to resume. It has also persuaded scientists to pursue the work and raised funds to support them. A similar body, the Heffter Research Institute in Santa Fe, New Mexico, was founded in 1993 by scientists with an interest in hallucinogens.
In the past couple of years their efforts have begun to pay off. Doblin is optimistic that psychedelic research is back for good, and this time it will do things right. "This gives us the chance to show that we have learned our lessons," he says. Halpern, too, is anxious to lay to rest the ghost of Leary. "That man screwed it up for so many people," he says.
With this in mind, Halpern says the first task for him and others is to evaluate the safety of psychedelics. And they are up against an entrenched orthodoxy: a 1971 editorial in The Journal of the American Medical Association warned that repeated ingestion of psychedelics causes personality deterioration. "Only a few of those who experience more than 50 'trips' are spared," it warned.
“I was reading all these papers from the 60s and going, whoa, wait a minute! How come nobody's talking about this?”
So Halpern's first big foray into psychedelic research was aimed at risk-assessment. In the late 1990s he launched a study of members of the Native American Church, who are permitted by US law to consume peyote. Halpern examined 210 residents of a Navajo reservation in the south-west US, who fell into three categories: church members who had taken peyote at least 100 times but had had little exposure to other drugs or alcohol; non-church members who abstained from alcohol or drugs; and former alcoholics who had been sober for at least three months.
Halpern tested the subjects' IQ, memory, reading ability and other functions. His interim results showed that church members had no cognitive impairment compared with the abstainers, and scored significantly better than recovering alcoholics. Church members also reported no "flashbacks" - sudden recurrences of a psychedelic's effects long after the initial trip. Halpern believes this study, which he expects will be published soon, shows that contrary to the 1971 editorial, peyote at least can be taken repeatedly without adverse effects.
He is now conducting a similar assessment of MDMA. This drug is sometimes called an "empathogen" because it heightens feelings of compassion and reduces anxiety. Anecdotal reports suggest it has therapeutic potential, and some psychiatrists used it alongside psychotherapy before it was outlawed in 1985. However, anecdotal and scientific evidence have also linked MDMA with brain damage, though the research is controversial.
Ecstasy impact
Judging the true impact of MDMA is complicated by the fact that users often combine it with other drugs and alcohol. To get around this, Halpern recruited a group of American mid-westerners who admitted taking MDMA but said they shunned other substances. He separated them into "moderate" users, who had consumed MDMA 22 to 50 times, and "heavy" users, who had taken it more than 50 times.
Halpern recently reported in the journal Drug and Alcohol Dependence that, compared with controls, heavy users displayed "significant deficits" in mental processing speed and impulsivity. Moderate users, however, had no major problems. Halpern believes this shows that MDMA's benefits may outweigh its risks for certain patients. And apparently the FDA and the McLean Hospital agree, since both have approved Halpern's plan to test MDMA as an anti-anxiety drug for a dozen late-stage cancer patients. Halpern still needs permission from the Drug Enforcement Administration, but he expects to begin recruiting patients soon.
He is also interested in the potential benefits of the true hallucinogens. In 1996, he reviewed almost 100 substance abuse trials involving LSD, psilocybin, DMT and ibogaine, an extract of the African shrub Tabernanthe iboga. Halpern found tentative evidence that the drugs can reduce addicts' cravings during a post-trip "afterglow" lasting for a month or two. Exactly how this happens is something of a mystery. A popular theory is that the benefits stem from the drugs' psychological effects, which include profound insights and cathartic emotions, but Halpern suspects that there may be a biochemical explanation too.
For now, however, Halpern isn't planning to pursue addiction therapy. He is more interested in another medical use for LSD and psilocybin: treating a debilitating condition known as cluster headaches. These attacks appear to be caused by swelling of blood vessels in the brain and are worse than migraines. Sufferers say the pain exceeds that of passing a kidney stone or giving birth without anaesthetics. They affect about 3 in every 1000 people sporadically, and 1 in 10,000 chronically. "There's a tremendous potential need for this," says Halpern, who investigated the problem after being approached by a patient group.
Many patients get little or no relief from painkillers, but some claim that small doses of LSD or psilocybin can alleviate the headaches and even prevent them from occurring. Halpern was intrigued; LSD is chemically related to ergot, a naturally occurring compound that constricts blood vessels, and the derivatives ergotamine and methysergide are commonly prescribed for migraines.
Halpern and his Harvard colleague Andrew Sewell are now gathering evidence to persuade licensing officials - and themselves - that LSD and psilocybin merit a clinical trial. Sewell has gathered more than 60 testimonials from cluster headache sufferers who have treated themselves with LSD or psilocybin.
Another member of the vanguard in the psychedelic revival is Charles Grob, a psychiatrist at the Harbor-UCLA Medical Center in Los Angeles, California, and co-founder of the Heffter Institute. After years struggling to get permits, Grob says he is slowly moving forward with a study into using psilocybin to reduce distress in terminal cancer patients. He points out that studies done in the 1960s suggested that psychedelics can help patients come to terms with their impending death. So far Grob has treated three patients, but he hopes to enrol more subjects shortly.
Grob has also led several investigations like Halpern's peyote study, but looking at ayahuasca, the DMT-rich shamanic brew. Ayahuasca often causes nausea and diarrhoea, and its psychedelic effects can be terrifying, but Amazonian shamans nonetheless prize it for its visionary properties. Since 1987 it has been a legal sacrament for several churches in Brazil, the largest of which is União Do Vegetal. UDV combines elements of Christianity with nature worship, and claims 8000 members.
In 1996 a team led by Grob reported in the Journal of Nervous And Mental Disease that UDV members who regularly took ayahuasca were on average physiologically and psychologically healthier than a control group of non-worshippers. The UDV followers also had more receptors for the neurotransmitter serotonin, which has been linked to lower rates of depression and other disorders. Many of the UDV members told the scientists that ayahuasca had helped them overcome alcoholism, drug addiction and other self-destructive behaviours.
“Addicts often end up filled with revulsion for their past lives and determined to change”
More recently, Grob has found that adolescents who grew up participating in ayahuasca ceremonies showed no ill effects and were less likely to engage in crime and substance abuse than members of a control group. Of course, Grob acknowledges that they could be benefiting from the social effects of membership in a church as well as the effects of ayahuasca itself. Grob plans to publish these results this year.
Several other scientists are quietly pursuing psychedelic research. Since 2001, psychiatrist Francisco Moreno of the University of Arizona in Tucson has been testing psilocybin as a treatment for obsessive-compulsive disorder. Psychotherapy and antidepressants such as Prozac help many patients, but some have such severe symptoms and are so resistant to treatment that they turn to electroshock therapy and even brain surgery. As with the work on cluster headaches, Moreno's study was motivated by reports from people with OCD that psilocybin relieves their symptoms.
So far, Moreno has given both sub-psychedelic and psychedelic doses of pure psilocybin to nine treatment-resistant OCD subjects, in a total of 29 therapy sessions. His preliminary findings suggest firstly that it is safe to ingest psilocybin, which was a primary concern of the trial. Beyond that, Moreno calls his results "promising", but won't discuss them further, since he plans to submit a paper to a peer-reviewed journal this year.
“By the mid-1960s, over 1000 papers had been published describing psychedelic therapy”
Meanwhile in Charleston, South Carolina, physician Michael Mithoefer is carrying out a MAPS-sponsored clinical trial of MDMA as a treatment for post-traumatic stress disorder. PTSD affects up to 20 per cent of people who experience a traumatic event, and involves distressing symptoms such as nightmares and panic attacks. Conventional treatments typically consist of cognitive therapy and antidepressants, but many patients don't respond to these. In the past year Mithoefer has given "MDMA-assisted" psychotherapy to six treatment-resistant patients, all traumatised by violent crimes; he plans to treat 20 patients in all.
The longest-running psychedelic therapy programme started almost 20 years ago in Russia. Evgeny Krupitsky, a psychiatrist who heads a substance-abuse clinic in St Petersburg, has treated more than 300 alcoholics and about 200 heroin addicts with ketamine. Used primarily in veterinary medicine, ketamine is an anaesthetic that can trigger an extremely disorienting hallucinogenic episode lasting an hour or so. Krupitsky's subjects often emerge from their sessions filled with revulsion for their past lives and determined to change. The therapists encourage these feelings with tricks such as forcing the subjects to sniff a bottle of vodka at the peak of their session; the patients' disgust often persists long after the ketamine's effects have worn off.
In one of Krupitsky's studies, 73 out of 111 alcoholics stayed dry for at least a year after their session, compared with 24 per cent of those in a control group. Yet his programme, which was funded by MAPS and the Heffter Institute, was recently shut down because the Russian government tightened restrictions on ketamine. Although Krupitsky says he and his colleagues "are in the process of getting permission to continue", it may be several years before research resumes.
Although disappointed by this setback, Doblin is encouraged by developments elsewhere. He is lobbying officials in Spain and Israel to approve studies of MDMA for PTSD, and is raising funds for a substance-abuse trial of ibogaine outside the US together with the Heffter Institute. MAPS has also supported Frans Vollenweider, a psychiatrist at the University of Zurich in Switzerland, who has done basic research on the physiological effects of psilocybin and MDMA, and hopes to begin clinical research soon.
Doblin's primary goal is to see psychedelics legally recognised as medicines. But he also hopes that someday healthy people may take these substances for psychological or spiritual purposes, as members of the Native American Church and União Do Vegetal do, and as he did in his youth. After all, drugs such as Prozac and Viagra are already prescribed not just to heal the ill but also to enhance the lives of the healthy.
It is still an uphill struggle. Government funds for psychedelic studies are hard to come by, and drug companies have shown absolutely no interest in supporting the research. But there are signs that the wind is changing. Although psychedelics are still classified in the US as schedule-1 drugs, and so are banned for all non-research purposes, in November a US Federal Appeals Court in Colorado ruled that a branch of the UDV based in Santa Fe, New Mexico, could import ayahuasca for use in ceremonies. Among the research findings cited in the court decision were Grob's studies showing no ill effects from ayahuasca. The Department of Justice is appealing the decision, but if the Supreme Court denies the appeal, UDV members in the US will be able to ingest ayahuasca legally.
Maybe, just maybe, after more than 30 years in the wilderness, this powerful, misunderstood but potentially mind-healing class of drugs is ready to be rehabilitated.
From issue 2488 of New Scientist magazine, 26 February 2005, page 36

Switzerland: Parliament blocks decriminalisation of cannabis

Ignoring the appeals of its health minister, the National Council
(Swiss Lower House of Parliament) on 25 September blocked
government moves to decriminalize cannabis. After an emotional
debate, the National Council voted 96-89 to take no action on the
government's proposed narcotics law revision.This means the
legislation will be kicked back to the Council of States (Upper
House of Parliament) which overwhelmingly approved it in
December 2001.

The government argued that police resources were too stretched
to enforce restrictive and outdated laws, with an estimated
500,000 people out of a population of 7 million being occasional or
regular soft drug users."Bans on cannabis and alcohol have
always proved a failure," Health Minister Pascal Couchepin said
in an impassioned speech to parliament. He said the proposed
legislation aimed to step up preventive measures and cut down on
black market profits.

In practice, cannabis users rarely face police sanctions as
Switzerland is more relaxed about drugs than many other
countries. However, there are big local variations and - given the
legal grey area - police often alternate between tolerance and
repression.

The upper house will reconsider the legislation in one of its
forthcoming sessions. It can either amend it or send it back
unchanged to the lower house. Supporters of a more liberal drug
policy hope that the package will finally win parliamentary
passage once the pressures of the general election have eased.

(Sources: Associated Press of 25 September 2003, Tagesanzeiger
of 25 September 2003)

High anxieties

What the WHO doesn't want you to know about cannabis

Health officials in Geneva have suppressed the publication of a politically sensitive analysis that confirms what ageing hippies have known for decades: cannabis is safer than alcohol or tobacco.

According to a document leaked to New Scientist, the analysis concludes not only that the amount of dope smoked worldwide does less harm to public health than drink and cigarettes, but that the same is likely to hold true even if people consumed dope on the same scale as these legal substances.

The comparison was due to appear in a report on the harmful effects of cannabis published last December by the WHO. But it was ditched at the last minute following a long and intense dispute between WHO officials, the cannabis experts who drafted the report and a group of external advisers.

As the WHO's first report on cannabis for 15 years, the document had been eagerly awaited by doctors and specialists in drug abuse. The official explanation for excluding the comparison of dope with legal substances is that "the reliability and public health significance of such comparisons are doubtful". However, insiders say the comparison was scientifically sound and that the WHO caved in to political pressure. It is understood that advisers from the US National Institute on Drug Abuse and the UN International Drug Control Programme warned the WHO that it would play into the hands of groups campaigning to legalise marijuana.

One member of the expert panel which drafted the report, says: "In the eyes of some, any such comparison is tantamount to an argument for marijuana legalisation." Another member, Billy Martin of the Medical College of Virginia in Richmond, says that some WHO officials "went nuts" when they saw the draft report.

The leaked version of the excluded section states that the reason for making the comparisons was "not to promote one drug over another but rather to minimise the double standards that have operated in appraising the health effects of cannabis". Nevertheless, in most of the comparisons it makes between cannabis and alcohol, the illegal drug comes out better--or at least on a par--with the legal one.

The report concludes, for example, that "in developed societies cannabis appears to play little role in injuries caused by violence, as does alcohol". It also says that while the evidence for fetal alcohol syndrome is "good", the evidence that cannabis can harm fetal development is "far from conclusive".

Cannabis also fared better in five out of seven comparisons of long-term damage to health. For example, the report says that while heavy consumption of either drug can lead to dependence, only alcohol produces a "well defined withdrawal syndrome". And while heavy drinking leads to cirrhosis, severe brain injury and a much increased risk of accidents and suicide, the report concludes that there is only "suggestive evidence that chronic cannabis use may produce subtle defects in cognitive functioning".

Two comparisons were more equivocal. The report says that both heavy drinking and marijuana smoking can produce symptoms of psychosis in susceptible people. And, it says, there is evidence that chronic cannabis smoking "may be a contributory cause of cancers of the aerodigestive tract".

From New Scientist, 21 February 1998

Pot luck

A little bit of what you fancy will not make you dull

Smoking cannabis does not have a long-term effect on intelligence, say researchers in Canada who have followed volunteers from before birth to early adulthood.

Heavy pot smokers did experience a dip in their intelligence quotient (IQ). But people who had once smoked heavily and then given up were right back up to normal, the study found. Light smokers appeared no different to non-smokers.

What the researchers do not know is if decades of pot-smoking could have a more lasting impact. Looking at long-term users in their 30s and 40s could show different results, admits Peter Fried, at Carleton University in Ottowa, who led the study. "Perhaps the nervous system isn't as flexible then," he says.

"You can't argue with what they are saying," says William Campbell, President of the Canadian Society of Addiction Medicine. "It doesn't surprise me or disappoint me."

Alison Motluk

Canadian Medical Association Journal (vol 166, p 887) From NewScientist.com's news service, 8 April 2002

Going to pot?

Reclassifying cannabis isn't enough to break the link to hard drugs

The great cannabis debate has been reignited in Britain by a government proposal to reclassify weed as a "softer" drug. If it's passed, Britain will be become one of many countries that are reducing the penalties for cannabis use.

So is this move part of a dangerous liberal trend that will lead to an explosion in the use of cannabis and other, more dangerous drugs? Or is it a long overdue step that does not go far enough towards breaking the link between marijuana, hard drugs and crime?

In Britain's three-tier classification system, cannabis is currently in Class B, along with amphetamines - a position that many argue is out of keeping with the danger it poses. The proposal is to reduce it to Class C, along with drugs such as anabolic steroids. This would mean milder penalties for possession, although it falls short of legalisation or decriminalisation.

Supporters of the scheme argue that it will free up police to tackle more dangerous drugs such as crack. In 1999, nearly 70 per cent of people arrested for drugs offences in Britain were charged with possession of cannabis. Processing each offender can take a police officer up to three hours.

What's more, figures from last year's British Crime Survey show that 44 per cent of 16 to 29-year-olds have tried cannabis at some point in their lives, with 22 per cent having used it in the last year. Clearly the law isn't holding everybody back. But will relaxing the law increase its use?

The evidence from countries that have gone even further than Britain proposes to is clear. In the Netherlands, where authorities have tolerated cannabis use since the 1970s, there has been no significant increase in use (New Scientist, 21 February 1998, p 30).

In South Australia, where users face civil sanctions such as fines rather than criminal penalties, there has been a small rise. But surveys by the National Campaign Against Drug Abuse between 1985 and 1993 showed that the rise was in line with that in states where use was still criminalised.

Results were similar during the temporary decriminalisation of pot in 11 US states in the 1970s. It seems that cannabis consumption has more to do with individual tastes and popular culture than the law. Or maybe lax policing means that changing the law makes little difference.

So reclassification is unlikely to result in an explosion of teenage potheads. What it could do is make youngsters more likely to trust the drugs information given by authorities. If those who take cannabis believe its legal status exaggerates the risks, they may be more likely to try more dangerous drugs.

For this reason, several drugs charities have welcomed the reclassification proposal. "Young people in particular may be less inclined to try other substances if they have more accurate information on the potential risks of each one," says Roger Howard, chief executive of the charity DrugScope.

But does cannabis lead to hard drugs regardless of what information is given? "Ecstasy killed my teenage daughter but her death began with that first cannabis joint," screamed a typical headline in one British tabloid last week.

A study published last year revealed that 99 per cent of young New Zealanders who took hard drugs had started on cannabis. The link is undeniable, but it's not clear if cannabis really is a "gateway to hard drugs" or whether the kind of people who take dope are more likely to try hard drugs too.

"I'm standing in the middle of the road on this debate," says David Fergusson of the Christchurch School of Medicine, who led the New Zealand study. His group actually set out to prove that progression to hard drugs is the result of people's personalities and peer group rather than the fact that they use cannabis. But they weren't able to.

They followed 1265 New Zealanders from birth to the age of 21, gathering detailed information on their background and behaviour. They found that 70 per cent of the group had tried cannabis, and a quarter had tried other drugs. Although two-thirds of cannabis users did not progress to other illicit drugs, nearly all hard-drug users started off on cannabis. And heavy cannabis users were most at risk.

Even when Fergusson took account of confounding factors, he found that there was still a link between heavy cannabis use and progression to harder drugs. "We have probably made the strongest effort anyone has made, but we cannot explain [the correlation] away," says Fergusson.

So what is the connection, if any? The most obvious link is that many cannabis users are in regular contact with drug dealers who can make more money from drugs such as cocaine than from dope. "We need to consider the options available to us regarding supply," says Howard.

The experience in the Netherlands, where allowing "coffee shops" to sell small amounts of dope means users don't usually come into contact with illegal dealers, suggests this does make some difference. According to an analysis published in Science in 1997, only 22 per cent of cannabis smokers in Amsterdam have tried cocaine, compared with 33 per cent of those in the US.

So trying to separate the markets for cannabis and hard drugs such as cocaine does appear to weaken the gateway effect. "But whether you can separate them or not is a big question," says Michael Farrell, a consultant psychiatrist at the National Addiction Centre in London.

Claire Ainsworth

From New Scientist, 3 November 2001

Doing drugs Dutch style

Within half an hour of arriving in Amsterdam, I've been offered sex, cocaine and ecstasy. It makes me think the critics are right about the effects of Amsterdam's soft drugs policies. But after three days of talking to the police, the "coffee shop" owners, treatment clinics and locals, I'm convinced that the approach is doing more good than harm.

The coffee shops began selling marijuana as early as 1976, and today there are about 900 such shops. Roel Kerssemakers, who works for the state-run Jellinek drug-abuse clinic, says this hasn't increased the number of smokers. "The forbidden-fruit effect is gone," says Kerssemakers. "There's very little peer pressure to smoke."

More importantly, the shops seem to have been fairly effective at separating soft-drug users from dealers who peddle harder drugs. "Coffee shops are the most hard-drug-free places in town," laughs Kerssemakers, thanks to regular visits from the police.

And most smokers seem content to try cannabis in their youth and then give up drugs completely. "Cocaine and ecstasy have more to do with nightclubs than with cannabis," Kerssemakers says. Police officers on the street agree. They say that the dealers I encountered are small-timers who target tourists rather than locals.

But recent changes in the drugs policy may have unintentionally jeopardised the separation between dope and harder drugs. In 1996, coffee shops were banned from selling to anyone under 18, which has "thrown a big vulnerable group onto the street", says Arjan Roskam, head of a union for coffee-shop owners.

While the amendment was intended to delay the age at which teenagers start experimenting with drugs, it has probably only diverted users to less regulated sources. According to the Trimbos Institute, a mental health and addiction centre in Utrecht, about 10 per cent of under-age smokers now buy from criminal suppliers.

The government also increased the penalty for growing marijuana from two years to four, discouraging smaller growing operations. "Now the crooks are in again," says Roskam. "I think it would be better if it were all legal."

He may have his wish. "There's a majority in parliament who are for legalising it, on the condition that we don't do it alone," says Kerssemakers. "If other big countries decide to, we would follow."

Nicola Jones, Amsterdam

From New Scientist, 29 August 2001

High anxieties

What the WHO doesn't want you to know about cannabis

Health officials in Geneva have suppressed the publication of a politically sensitive analysis that confirms what ageing hippies have known for decades: cannabis is safer than alcohol or tobacco.

s
As the WHO's first report on cannabis for 15 years, the document had been eagerly awaited by doctors and specialists in drug abuse. The official explanation for excluding the comparison of dope with legal substances is that "the reliability and public health significance of such comparisons are doubtful". However, insiders say the comparison was scientifically sound and that the WHO caved in to political pressure. It is understood that advisers from the US National Institute on Drug Abuse and the UN International Drug Control Programme warned the WHO that it would play into the hands of groups campaigning to legalise marijuana.

From New Scientist, 21 February 1998