26 Sep “Cannabis: The facts” or “Cannabis: The speculation”?

The NHS Choices website carries an article entitled “Cannabis: the facts“. NHS Choices is usually a good source of information and indeed this page carries some sensible sounding advice, for example, about the ‘gateway effect’:

Does cannabis lead to other drugs?

While most people who use harder drugs like heroin have used cannabis, only a small proportion of people who use cannabis go on to use hard drugs. However, buying cannabis brings you into contact with the illegal drugs trade, making it more likely that you will be exposed to other drugs”

It does however, also contain some rather tenuous and unbalanced remarks such as:

If you use cannabis regularly it can make you demotivated and uninterested in other things going on in your life, such as education or work. Long-term use can affect your ability to learn and to concentrate”

This is simply sloppy writing, using cannabis at 6.30pm every Friday night isn’t going to be more dangerous than doing so at various times during the week. Of course they don’t mean using “regularly”, they mean “heavily”, or perhaps “constantly”, or in the jargon, “chronically”. Likewise, by simply “long term use” they probably mean heavy use over an extended period.

To be fair; it only says “affect your ability…” it doesn’t say for better, or worse! But these are exactly the kind of ambiguity that does not belong on a facts page.

Indeed there is evidence that cannabis does the exact opposite and is used by many to ease the symptoms of depression and to get motivated.

The fact is that the vast majority of people who use cannabis regularly lead completely normal, happy, healthy lives.

There are countless high profile examples of men and women who use cannabis regularly and have highly successful and productive careers in all walks of life; Business, Science, Technology, Sport, Entertainment, Music, etc. To name but a few; Steve Jobs, Brittany J Confer, Carl Sagan, Stephen Jay Gould, A.C.Braddock, Ross Rebagliati, Bob Marley, Willy Nelson, Alanis Morissette, Paul McCartney, Snoop Dog, Sarah Silverman, Julianna Carella, Nick Diaz, Madonna, Barbara Streisand, the list goes on-and-on-and-on…

This claims to be a page of factual information about cannabis. A fact is defined as:

noun
1. A thing that is known or proved to be true

Much of the information contained on the page is not factual.

The first clue that this fact page is weak is the sheer number of qualifying terms such as ‘Could’, ‘Can’ and ‘May’. Whilst this language correctly identifies the uncertainty around these statements, it detracts from the facts. A fact page should include just that. Facts, supported by evidence. Therefore, the risks need to be quantified.

“Can” 13 times
“May” 8 times
“Could” 2 times
“Some” & “Sometimes” 7 times
“Likely” 4 times

It also appears that the author does not understand the relationship between correlation and causation, there is much speculation. At least in this statement they acknowledge it:

It’s not clear why the risks are higher for people who start using cannabis when young. It may be linked to the fact that, during the teenage years, the brain is still forming its connections and cannabis interferes with this process.

This is, however, not something confined to cannabis use, it is a general point concerning all drug use by young people – and indeed possibly other activities such as gambling, excessive use of social media and so on.

Is a ‘facts’ page an appropriate place to air these views? There are many other views that have not been represented such as; It may be that teenagers with mental health issues feel marginalized and let down mainstream treatments and are therefore more likely to seek alternative medication. Heavy use of cannabis (or any drugs) may be a sign of an emerging mental health problem, rather than a cause of it. Although good advice, it is not a cannabis specific fact.

The section addressing risks contains the following fact:

Cannabis affects your ability to drive. This is one of the reasons why drug driving, like drink driving, is illegal. One French study found that drivers who had been using cannabis were more than twice as likely to cause a fatal car crash.

A case study is alluded to and a numerical value attributed to the risk, but there is no mention of other studies which indicate cannabis has a low risk of impairment.

Neither is there any indication of the level of intoxication required to achieve that level of risk.

Context for any statistic is important, for example, the legal limit for drink driving is 80mg/l, yet The Royal Society for the Prevention of Accidents has claimed

between 50mg and 80 mg drivers are 2 – 2.5 times more likely to be involved in an accident than drivers with no alcohol, and up to 6 times more likely to be involved in a fatal crash.

"Cannabisthe facts"

Regarding smoking as a method of consuming cannabis:

If you smoke it, cannabis can be harmful to your lungs. Like tobacco, it contains cancer-causing chemicals (carcinogens) that increase your risk of lung cancer. It can also make asthma worse, and cause wheezing in people without asthma. If you mix cannabis with tobacco and smoke it, the risks to your lungs are higher.”

This advice needs to be more nuanced.

It is true that breathing in any smoke is bad for the lungs and cannabis smoke is no different in that respect. Cannabis can lead to lung problems such as bronchitis.

However cannabis smoke also contains cannabinoids which have protective actions in respect of cancer. Interestingly another NHS document “A summary of the health harms of drugs” states (Page 32)

No conclusive evidence that cannabis causes cancer

It goes on to qualify this by stating observations are complicated by the concurrent use of tobacco. Neither NHS document takes to logical step of advising cannabis users not to smoke mixed with tobacco, which frankly is illogical and is probably the result of political interference.

Can’t argue with the risks of adding tobacco though! Visit CLEAR’s TOKEpure campaign page.

And on the highly controversial and much quoted subject of mental health:

Cannabis can harm your mental health. Regular use is associated with an increased risk of developing a psychotic illness, such as schizophrenia… Your risk of developing a psychotic illness is higher if you start using cannabis in your teens and if you have a family history of mental illness. Cannabis use has also been shown to increase the risk of a relapse in people who have schizophrenia, and could make existing symptoms worse.

“Associated” with an increased risk is a narrative rather than fact and “higher” risk is not quantified, perhaps because the risk increase is so very small and no study has yet established a cause. The clearest fact is the official figure for admission for cannabis psychosis is just 28 per year for those aged 16 – 24. Incidence of schizophrenia, even rarer but it is a complex area and the focus of much study. See this summary of current scientific research: Does Marijuana Use Increase the Risk of Psychosis (Including Schizophrenia)?

Thankfully the most factual section on the page is the section on Medical Cannabis:

Does cannabis have medicinal benefits?

Herbal cannabis contains many different compounds, called cannabinoids, which have different effects. One of these cannabinoids – tetrahydrocannabinol, or THC for short – is one of the the active ingredients of a prescribed drug called Sativex. Currently this is only licensed in the UK as a treatment to relieve the pain of muscle spasms in multiple sclerosis.

Further research is under way to test the effectiveness of cannabis-based drugs for a range of other conditions including the eye disease glaucoma, appetite loss in people with HIV or AIDS, epilepsy in children and pain associated with cancer. We won’t know whether or not these treatments are effective until trials have concluded.”

Actually Sativex contains not only the two active cannabinoids, THC and CBD but also all the other minor active constituents of cannabis. Sativex is not a single drug product.

Finally, if you found the page wanting, where do they send you to get more information? Frank. But that’s a whole different article!

The NHS Choices page was last updated in Oct 2014 and is not due for review until Oct 2016. Hopefully this poor reporting will be addressed before then.

Sam Skey

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