The recent hoopla over a London study linking the use of high potency cannabis with first-episode psychosis only strengthens the case for regulating the drug -- and for the media to be more responsilbe in their coverage of such issues.

The study in question -- published in The Lancet -- found that those presenting with psychosis in south London were more likely to have used strong cannabis regularly, rather than have never used the drug, something which certain media outlets distorted into fear mongering, sensationalist dross.

With the dust now settled following last week’s media frenzy, it's worth looking at some of the key points to take away from the study and its aftermath.

Assumptions on cannabis potency

To begin, it can’t be overstated that any and every study has its limitations; there are simply too many factors to account for to produce an airtight piece of research and the authors clearly state as such, noting the findings to be correlational rather than concluding that cannabis causes psychosis.

The south London study does, though, make some problematic assumptions about the potency of different types of cannabis. From the paper’s introduction:

“ … skunk-like types of cannabis, which contain very high concentrations of [tetrahydrocannabinol] (THC), seemed to have a greater psychotogenic effect than did hash (resin), which is known to contain much less THC.”

This is not a truism. Indeed, the 2008 Home Office Cannabis Potency Study that the paper partly bases this assumption on -- along with analysis of police seizures of cannabis in London in 2005 -- shows this, with the average potency of sinsemilla (skunk) coming in at 16.2 percent THC compared to 5.9 percent for cannabis resin. But, this does not necessarily mean that study participants were using cannabis at these THC levels, or that the levels in what they were using conformed to the Home Office and police findings.

To highlight the fact resin is not always less potent, samples of herbal and resinous cannabis collected from a range of users and growers for a documentary in 2013 found that resin was coming in with the highest THC content (around 15 percent) with the next highest level sitting just above 8 percent (both of which were herbal samples). After this, the potency levels dropped off markedly.

Simply put, potency varies over time and place and is certainly not strictly dependent on type. This study covers a six-year period from 2005-2011, more than enough time for THC levels to fluctuate markedly in whatever variety of cannabis study participants were consuming. What's more, it limits the type of cannabis use to just "low potency [hash-type]," and, "high potency [skunk-type]," seemingly discounting the different gradations in between. For example, a person who uses "weed" that was in fact of a lower THC concentration may opt to categorize this as high potency skunk based on the presented options.

Ideally, of course, the actual cannabis people were using would have been submitted for independent forensic analysis to determine the actual levels of THC and cannabidiol (CBD), which the study highlights has been found to possibly contain antipsychotic properties. Suzi Gauge notes that such detailed analysis “isn’t practical in studies of this size and design,” which may well be true. However, it would certainly help the claim that high-potency cannabis increases the risk of psychosis stand up further.

Finally, the study offers the theory that skunk may have been preferred by patients presenting with first-episode psychosis as a way of self-medicating, only to shoot this possibility down immediately by suggesting such a move would be “counterintuitive” given the higher levels of THC. Surely patients would choose resin/hash, which has higher concentrations of CBD that reduces anxiety, the authors suggest.

This supposition that people are well informed as to the effects of CBD and THC and the concentrations of each in what they are smoking is a stretch given both the lack of good public education on drug use and the very nature of the black market; you don't know what you're getting! Therefore, it can’t truly be discounted that people did increase use under the impression it would ameliorate their condition, or that it may have helped alleviate some of the symptoms in individual cases.

The need for media responsibility

The media -- as it is wont to do -- slipped into the seemingly default position of exaggerating or generally misrepresenting findings related to a drug study knowing full well it would draw in the readers. Gauge’s aforementioned commentary picks out a few of the offenders here.

If anything, sensationalist media coverage highlights the need for better primary source research by journalists, particularly when it is concerning something as serious as a potential contributing factor to mental illness.

As previously stated, public education on the effects of drugs and the proper way to mitigate their harms when using is at best poor. Journalists only perpetuate this in their apparent prioritization of reader numbers over accurate reporting.

A case in point would be the write ups of Jon Snow's experience taking high potency cannabis for a separate study which unfortunately gained publicity in the immediate aftermath of the paper. Many chose to focus on the terror it induced in him, the fact he felt like his "soul had been wrenched from [his] body," rather than the point of the study itself -- to look at the effect of drugs on human cognition, emotion and behavior. Snow is by his own admission an unseasoned cannabis user, and was subjected to an extremely strong dose in a less than desirable setting which would only exacerbate his uneasiness. The outcome, was therefore, unsurprising. Don't tell that to journalists blindly searching for a good top line, though.

At the very least, distortions such as these are sensationalist rubbish. At worst, they are grossly irresponsible. This is an area that needs more research, not journalists clambering over each other to see who can write a scarier headline.

Sadly, Professor Robin Murray, one of the study’s authors, was guilty here as well with flippant comments made to The Guardian such as: “The argument initially was that the people who are going to smoke cannabis are a bit odd anyway. In south London, two-thirds of people have used cannabis and it seems unlikely that two-thirds of people are abnormal.”

While he may be trying to be funny, stigmatizing people who use drugs, especially as it relates to their mental well being, by referring to them as “a bit odd,” and “abnormal” is extremely damaging.

The case for regulation

Government ministers were quick to jump on the study's findings as evidence that the UK should not decriminalize cannabis. In light of the possible links between regular use of high potency cannabis and the onset of mental illness, this is indeed not an argument for decriminalization; this is about as strong a case you could have for regulating the drug!

With regulation, the government would be able to significantly mitigate the harms associated with use by:

Drastically improving public education (something which should be done regardless of regulation) by informing people how to use responsibly and safely.

Imposing age controls (no one under the age of 18 would be able to purchase cannabis, for example).

Controlling the potency (setting an upper limit for THC levels and ensuring all forms sold had CBD levels kept at a balanced ratio).

These are just a few things that could be done to safeguard against the misuse of cannabis. Of course, the black market will never be fully removed from the equation -- one need only look at alcohol and cigarettes as evidence of this -- but a significant dent can be made in it.

The paper's emphasis on the need for greater public education around high potency cannabis is a good starting point. Building on this foundation, though, by enforcing smarter controls will only help protect against the potential deleterious effects of cannabis. Without this kind of substantive policy reform, people will remain vulnerable to the whims of the black market.