Sunday, July 29, 2007


Reading the report below in conjunction with various previous reports (e.g. here and here) does lead to the view that cannabis can do serious harm. That is no reason for banning it, though. Alcohol and motorcars do serious harm too. It is more an argument for legalizing it so that any problems can be better dealt with

Cannabis users are 40 per cent more likely to develop a psychotic illness than non-users, a study has found. Heavy users are more than twice as likely to suffer mental illness, according to a group of British academics, who calculate that about one in seven cases of conditions such as schizophrenia is caused by cannabis.

The warnings come as the Prime Minister and the Home Secretary signalled that the "softly softly" era for cannabis may be coming to an end. Gordon Brown said last week that the Home Office would be consulting on whether it had been right to downgrade cannabis from a Class B to a Class C drug in 2004. Jacqui Smith, the Home Secretary, is to ask the Advisory Council on the Misuse of Drugs to review the evidence.

The paper, published in The Lancet, is written by a group of seven psychiatrists and psychologists from Bristol, Cardiff, London and Cambridge. They have pooled the findings from 35 studies in a number of countries, including the United States, Germany, the Netherlands, Sweden and Britain, and concluded that there is "a consistent association between cannabis use and psychotic symptoms, including disabling psychotic disorders".

They admit that they cannot be certain that the association means that there is a simple cause and effect, but say that policymakers "need to provide the public with advice about this widely used drug". They go on: "We believe there is now enough evidence to inform people that using cannabis could increase their risk of developing a psychotic illness later in life."

As well as looking at psychotic illness, they looked for evidence that cannabis could cause affective disorders such as depression, anxiety and suicidal thoughts. Almost all the studies point towards an increased incidence of such disorders. The evidence is less strong, the writers say, but is still of concern.

The study was welcomed by many experts, but others counselled caution. Leslie Iverson, of the University of Oxford, a member of the advisory council, said: "Despite a thorough review the authors admit that there is no conclusive evidence that cannabis use causes psychotic illness. Their prediction that 14 per cent of psychotic outcomes in young adults in the UK may be due to cannabis use is not supported by the fact that the incidence of schizophrenia has not shown any significant change in the past 30 years."

But Robin Murray, of the Institute of Psychiatry at King's College London, called it "a very competent and conservative assessment of what research studies tell us about the relationship between cannabis and psychiatric disorders". He said that the risk could be even higher then the authors had estimated, because the cannabis available today was stronger than in the past. "This report cannot tell us whether the risk is higher with the use of the skunk-like preparations which are now widely available, and which contain a higher percentage of tetrahydrocannabinol," he said. "My own experience suggests to me that the risk with skunk is higher. Therefore, their estimate that 14 per cent of cases of schizophrenia in the UK are due to cannabis is now probably an understatement."

Martin Barnes, chief executive of Drugscope and also a member of the council, said: "Cannabis is not harmless, and although it has been known for some time that the drug can worsen existing mental health problems, it may also trigger the onset of problems in some people." "The challenge is to ensure that information on cannabis use and the associated risks is understood by teachers and health professionals working with young people and conveyed in ways that young people will listen to. Since reclassification, cannabis use has continued to fall. We need to make sure this trend continues."

Marjorie Wallace, chief executive of the mental health charity SANE, said: "The Lancet report justifies SANE's campaign that downgrading a substance with such known dangers masked the mounting evidence of direct links between the use of cannabis and later psychotic illness. The debate about classification should not founder on statistics but take into account the potential damage to hundreds of people who without cannabis would not develop mental illness. "While the majority can take the drug with no mind-altering effects, it is estimated that 10 per cent are at risk. You only need to see one person whose mind has been altered and life irreparably damaged, or talk to their family, to realise that the headlines are not scaremongering but reflect a daily, and preventable, tragedy."

Martin Blakeborough, director of the Kaleidescope Project and a member of the council, said that it would be a waste of public money for the same panel, with the same evidence, to review the issue again. "There is significant danger in reviewing cannabis again, as it takes experts' minds off more important issues. Classification itself, although important, is not as urgent as the increasing epidemic of hepatitis B and C among drug users and the wider community, or the increase of stimulant drugs in our community."


Diabetes drug bad for hearts?

The risk sounds small when you look at the alternatives. There is a more extensive report here that sets out the rather odd findings and says that the results of the study are inconclusive

Drugs prescribed to 100,000 patients in Britain to treat diabetes double the risk of heart failure, a study has suggested. The finding is a blow to GlaxoSmithKline, whose drug Avandia is one of the drugs involved. The new analysis, which pools data from 78,000 patients, finds that one in fifty patients treated with either Avandia or a similar drug, Actos, for two and a half years would be admitted to hospital with heart failure.

The two drugs reviewed in the new analysis in Diabetes Care are prescribed to millions of patients to treat type 2 diabetes. They are approved by the National Institute for Health and Clinical Excellence (NICE) for use on the NHS. The drugs already carry a warning that they are not suitable for patients suffering from, or at risk of, heart failure. But the new study suggests an increased risk even for those who have never suffered the condition. Two advisory panels for the US Food and Drug Administration are now reexamining both drugs.

A study in The New England Journal of Medicine in May linked Avandia to a 43 per cent increased risk of heart attacks. The European Medicines Agency (EMEA) said that its Committee for Medicinal Products for Human Use (CHMP) is carrying out a reevaluation of both drugs. The new research was carried out at the University of East Anglia (UEA) and Wake Forest University in North Carolina, in the US. It was led by Yoon Loke, a clinical pharmacologist at UEA. The experts suspect that the drugs cause fluid retention, which could trigger heart failure.

Alastair Benbow, the European medical director of GlaxoSmithKline, said: "Long-term studies have not shown an overall increase in heart deaths between patients taking Avandia and other diabetes drugs. "Heart failure can be well managed by using diuretics, and we have to remember that type 2 diabetes itself has devastating consequences, including stroke, blindness, amputation and kidney failure."



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


1 comment:

Anonymous said...

Errrm... Your statement about Eskimo's suffering no ill effects of a high fat diet may not be accurate. Inuit have a lifespan 10 years shorter than fellow Canadians and although there is not a direct link to the high fat diet, it cannot be ruled out at this stage of our understanding.