Tin hats on again; the Daily Mail had a cannabis news story to crow about this week

Teenage cannabis smokers face bigger risk of full-blown mental illness in later life

Teenage cannabis users are more likely to suffer psychotic symptoms that raise the risk of full-blown mental illness in later life, claim researchers.

and

Their findings will bolster the Government’s decision last month to restore cannabis to the harsher Class B status against the advice of its own scientists.

This was a report on a study carried by the The British Journal of Psychiatry “Association of cannabis use with prodromal symptoms of psychosis in adolescence” UKCIA was sent a copy of this research anonymously and you can see it here.

The authors do indeed claim this indicates a causal link between cannabis use and the onset of serious mental illness. However, at least some aspects of the study give pause for thought:

For example, the young people – who are in the throws of puberty remember – are asked ‘whether the subject had a feeling that something strange or inexplicable is taking place in oneself or in the environment’. No kidding!

The NHS Choices website had a commentry on this study, which is worth quoting from:

What does the NHS Knowledge Service make of this study?

There are limitations to a study such as this that should affect the interpretation of results, particularly where causation is being claimed:

  • As the researchers collected data on cannabis use and early warning symptoms at one point in time, this is a cross-sectional study. Due to their design, cross-sectional studies cannot establish causation. At best, the researchers can say that cannabis use is “associated with” or “linked to” the prodromal symptoms. Other factors that may be involved become important when interpreting results of studies such as these.
  • Although the researchers took into account early emotional and behavioural problems around age eight, they did not account for mental problems that may have occurred between ages eight and 16 years.
  • Importantly, a positive “score” on the PROD-screen questionnaire does not diagnose psychosis. It is used to indicate whether a person is entering the period of early symptoms or changes in function that may come before psychosis. However, even for this, the score is not 100% accurate at predicting psychosis, or even proven as a tool for diagnosing the prodrome. The researchers used a shortened form of the original PROD-screen questionnaire (they reduced it from 21 questions to 12). It is unclear what effect this would have on the overall accuracy of the screening test. If it was too inclusive, i.e. there were a high number of false-positives, the relationship between drug use and symptoms would have been overstated.
  • The researchers grouped all adolescents who had ever used cannabis into one category for analysis (i.e. they do not differentiate between adolescents who have tried cannabis once and those who are regular users).

Overall, this study points to an area that requires more research, but because of its design, the study does not prove that cannabis causes psychosis. Confirmation of the usefulness and accuracy of the PROD-screen in predicting increased risk of psychosis will also be important. When the findings are considered in light of a growing body of evidence of a link between cannabis use and mental health problems such as schizophrenia, it seems wise to limit the use of the drug. This is not only because of considerations of the effects on mental health, but also the well-established risks for cancer and other diseases that are associated with smoking.

Which brings us back to the Mail’s opinion quoted above:

Their findings will bolster the Government’s decision last month to restore cannabis to the harsher Class B status against the advice of its own scientists.

Oh yeah, moving cannabis back to class B is going to stop kids from using it isn’t it? Of course it isn’t. But whatever the truth in all this it’s another reason that kids shouldn’t use cannabis. Most people would agree that kids as young as 13-15 shouldn’t use cannabis, or any drug including alcohol and maybe even caffeine.

We all know that young kids brains are developing and to throw any psychoactive drug in to the mix isn’t going to do them any good. So yes, of course, we should be doing all we can to keep kids away from drugs. How does making them illegal do that? Simple: It doesn’t, giving kids a criminal record doesn’t and exposing them to the unregulated street dealers of prohibition era Britain doesn’t either.

If we really want to prevent our kids from using cannabis we need take the control out of the dealers hands. Street dealers don’t ask for ID when they sell, all you need to buy a deal of weed is £10 or so. That is the naked truth of prohibition and if we are serious about wanting to protect kids, a legalised, regulated supply is the only way to go.

The other big story this week was “proof” that cannabis causes structural brain damage (Long-Term Cannabis Users May Have Structural Brain Abnormalities). Scientists in Australia performed high-resolution structural magnetic resonance imaging on 15 men (average age 39.8 years) who smoked more than five joints daily for more than 10 years. Their results were then compared with images from 16 individuals (average age 36.4) who were not cannabis users. They claim to have found

The hippocampus, thought to regulate emotion and memory, and the amygdala, involved with fear and aggression, tended to be smaller in cannabis users than in controls (volume was reduced by an average of 12 percent in the hippocampus and 7.1 percent in the amygdala).

The first comment about this is the sample is too small to draw any real conclusions from, but again, as so often with all this are we looking at cause or effect? As an article in the New Scientist by Andy Coghlan stated:

So for now, we simply don’t know for sure whether cannabis is genuinely changing brain architecture. And the same dilemmas apply to study of all addictions. Which is why some researchers contacted by New Scientist cautioned against sensationalising the Australian results.

“You must be very careful looking at this paper in isolation,” says Tim Williams, who studies addiction at the University of Bristol. “With this kind of study, you can’t tease out cause and effect.” Williams also pointed out that a study in 2005 of long-term cannabis users by researchers at Harvard Medical School found that there was no effect on the size of their hippocampuses. “I’m surprised the Australians found an effect where others haven’t,” he adds.

The take-home message is clear! Be cautious about concluding too much from addiction studies which might confuse cause and effect. Yes, it could be down to the drug, but equally, it could be down to your pre-existing brain architecture, and the effect of that on your personality.

As some of the comments following the above article allude to which you can read on the page, the role of tobacco might be significant in these observed results, but I forgot, tobacco isn’t a drug, is it?

Away from all this brain science (or perhaps pseudo science) another study this week showed CBD – the cannabis “good guy” remember – halts the development of cancer. Marijuana Chemical Cannabidiol Halts Spread of Breast Cancer Tumors. For some strange reason though, the Daily Mail missed that story.

One last story worth mentioning is about mental illness but not about about cannabis, it’s about booze. You could be forgiven for thinking that cannabis is the only drug linked to serious life threatening psychosis, but nothing could be further from the truth as demonstrated so sadly this week by Paul Gascoigne – Gazza – as he seemingly follows in the tragic footsteps of that other football legend George Best.

To quote The Sun (it had to happen eventually)

PAUL Gascoigne’s breakdown is a “mirror image” of George Best’s battle with alcohol, the late star’s ex-wife has said.

Alex Best, 36, said fans flocked to buy George booze. She said: “People want to say we’ve bought Paul Gascoigne a drink, or George Best a drink. They’re killing him.

“It’s a mirror image of George. It’s tragic something like this can happen again.” Manchester United legend Best died in 2005 aged 59.

Ex–England star Gazza, 41, was sectioned under the Mental Health Act for the third time this year on Tuesday.

Sad, really sad. No other words to describe what’s happened.

While scientists use debatable research looking for minute changes with hi-tech equipment to “prove” the harms cannabis may cause to people who use it, we have near daily evidence of the harm alcohol can do rammed in our faces. We often see it in the street with people we perhaps collectively ignore, but sometimes it hits someone famous and gets reported. For some people the recreational use of drugs can get out of control, and something like that is what’s happened to Gazza. It happens to lots of people, who just happen to be a minority.

What we have to have with a drugs policy is something which reduces the risk of tragedies like this  happening to a minimum, protects those at most risk from harm and supports casualties toward recovery. With alcohol we try to reduce the risks through regulation and control of the supply side, with cannabis we try to do the precise opposite.

Certainly no-one is suggesting Gazza would have been protected from the harms of booze by being criminalised for getting drunk or protected in any way by buying contaminated moonshine from dodgy dealers. Rather – and quite rightly – we are (hopefully) looking at better regulation of the booze trade.

For cannabis we ensure there’s no regulation over the supply side and treat the user – potential casualty – as a criminal.

So why is it right to do it one way for booze and another for cannabis? How can two diametrically opposed regimes both be the right way to solve the same problems?

Ah but then to politicians, as with tobacco, alcohol isn’t really a drug…