Monday 16 February 2015

The skunk-psychosis link is another reason to legalise weed

The Lancet Psychiatry has published a study which finds that daily users of cannabis are three times more likely to develop schizophrenia than those who never use it. The cannabis legalisation lobby will no doubt be picking holes in the research, and I hope they do a better job than Suzi Gage in The Guardian who resorts to making generic criticisms of epidemiology and saying 'correlation isn't causation' (as she tends to do when she doesn't like the findings but can't spot a specific flaw).

I am a card-carrying member of the cannabis legalisation lobby myself, but I don't need to pretend that cannabis is without risk to defend my position. I can do so on moral and practical grounds. The moral (libertarian) argument is that it is not for the government to persecute people for taking drugs so long as users are reasonably well-informed about the risks. The pragmatic (free market) argument is that the social and economic costs of prohibition are greater than costs of regulated drug use.

My reading of the evidence is that cannabis probably is associated with psychosis and schizophrenia in some way and that questions about reverse causation and confounding have been largely answered (see here, here, here and here). The new Lancet study does not come as a surprise, but it is made more interesting by its analysis of what type of cannabis is associated with psychosis.

These are the main findings:

Three points stand out. Firstly, that there is no association between cannabis use and psychosis for those who started smoking the drug after the age of 15. Secondly, that only those who use cannabis very frequently are at higher risk. Thirdly, that it is only skunk marijuana—which is high in THC—that seems to increases risk.

The difference between hash and skunk consumption in the case and control groups is striking. 44 per cent of the control group had smoked hash, but only 14 per cent of the group with psychosis had done so, whereas only 19 per cent of the control group had smoked skunk while 53 per cent of the group with psychosis had done so.

Opponents of drug reform will use this study to support continued prohibition—the Home Office has already done so—but it is actually another reason to liberalise.

The purpose of legalisation is not to have a free-for-all but to have a regulated market. In my book The Art of Suppression, I set out a proposal for legalisation that would allow drugs to be sold in much the same way as alcohol and tobacco. It is a blueprint that paves the way for opium bars, head shops and the sale of regulated drugs in pharmacies and nightclubs, for example, but it does not see a place in the market for every drug that has emerged in the century of prohibition.

Alcohol is legal, but you cannot go into an off licence and buy a litre of pure ethanol. Similarly, a sound system of drug legalisation would allow the sale of opium, but not heroin. It would allow the sale of cocaine (or cocaine-based products), but not crack. And it would allow the sale of pre-rolled, manufactured spliffs but there would be limits on THC content that would effectively ban the sale of skunk.

Would this system eliminate demand for crack, heroin and skunk? Probably not—and certainly not overnight—but it would help to shift consumers away from the strongest and more harmful derivatives of drugs. Who bought moonshine after Prohibition was repealed?

The aim is to bring the market back to where it was before the war on drugs began—when consumers, not suppliers, called the shots. Prohibition shifts power from consumers to suppliers. The sale of strong spirits soared during Prohibition while beer sales fell. Why? Because beer was too bulky for bootleggers and spirits offered greater profits. Skunk, crack and heroin offer the same benefits to drug dealers. Being highly concentrated, they are less bulky and therefore easier to smuggle and carry. The strongest derivatives always prosper under prohibition, but they carry the greatest health risks.

So it is with cannabis. Skunk was developed under prohibition for prohibition. It cannot now be uninvented, but a system which allowed the general sale of lower-THC varieties (to adults) would undo much of the damage that prohibition has done in this, as in every other, market.


Christopher Snowdon said...

I often get pissed off by the cannabis lobby as the main plank of their argument is so often "but alcohol is worse", which isn't really going to get non users on their side.

But I have to say I saw this reported in the Mail yesterday and thought that, contrary to the predictable line taken by the paper, it actually supported the legalisation of lower-THC varieties of cannabis, as they were shown to have zero link with psychosis.

Christopher Snowdon said...

They act as if 'psychosis' is some objectively defined 'condition'. On a continuum of 'bizarre beliefs', become bizarre enough, and you'll get name-called as 'psychotic' by psychiatry. It's obvious that young people who are into escapism behaviors, are more likely to, some of them, wind up deeply lost and overwhelmed with the world, whether it is burying your head in a bong, a bible or a computer game all day, and some of them are going to wind up spouting bizarre things and be called 'psychotic'. There is no objective test for this alleged 'medical condition', it is simply what psychiatrists call people who they catch believing and behaving strangely. The vast, impenetrable complexity of human behavior, is not reducible to facile creation stories of 'THC in, believing you're Jesus Christ out'.

Not to mention the nosological quackery psychiatry suffers from, where any given young person with strange beliefs is just as likely to have the 'schizophrenia' label slapped on them as the 'bipolar' label or the 'brief reactive psychosis' label, all depending on the caprices, and 'diagnostic' habits of whichever state psychiatrist quack they get forcibly handed over to. Subsequent second, third, fourth opinions can produce further changes in 'diagnosis' still, and for any member of the 'schizophrenia' group in a study, that same person could easily have been enrolled in the 'bipolar' group of some other study just a few years ago before diagnostic creep kicked in, in their case.

It's not going to be good for your psychological well-being to bludgeon your faculties with strong drug use daily, but to use it as some catch-all explanation for a putative 'disease' that has no biomarker, is a completely different kettle of fish to smoking=lung cancer (a real, physical disease), not some reified psychiatric label that gets slapped on people who exhibit a disparate selection of bizarre thoughts and ideas. Young people should be warned about the dangers of both drugs and the dangers of throwing a perfectly good medicine degree down the toilet by specializing as a psychiatrist, and the dangers of trusting some DSM wielding, drug dispensing quack who sees 'brain disease' everywhere he looks but hasn't seen inside the human body since medical school, and performs no examinations on any of the brains of the people he's callously and criminally disempoweringly led to believe have 'diseased brains'. There's much more rotten in psychiatry than mere, side distractions like the debate over cannabis.

Christopher Snowdon said...

Heh! That's very much the juxtaposition between smokers and vapers, with the vapers attempting to occupy the moral high ground at the expense of smokers; a position which I consider extremely regrettable.

I was a very heavy dope user for many, many years, but I didn't start smoking dope until I was 17. I also found that when Skunk hit the market, after a short initial burst of enthusiasm for this 'latest generation' supergrass I decided that it wasn't very nice. It was, basically, too strong.

What's the point of smoking dope if it just induces a semi-coma and doesn't really get you high? And maybe as a result of my preferences, although I might be a bit of a renegade, I wouldn't classify myself as 'psychotic' in any sense. In fact despite my occasional forays into tinfoil-hattery, I am essentially rather boringly rooted in reality. But I can well imagine that if someone smoked Skunk like I smoked the less brutal permutations, it could well have a negative(?) effect on ones personality.

In the years from 1967 - 1969 I spent quite a lot of time in a place called Chitral, which is in the North-West Frontier area of Northern Pakistan. Chitral is (or maybe was, given the war-zone it has become, being on the Afghan border) to my mind the area that produces the best hashish in the world (and has done for a very long time; certainly centuries). And the way they grade hashish there is by the quality of the high. If it tends to turn you into a zombie (the bulk of the harvest), then it gets sent down to the plains below for the unwashed and uncritical masses to consume (or exported to the west).

If it puts you on a higher plane without impeding your ability to deal with what day-to-day life tends to send your way, then it never leaves the valleys, but is kept for local consumption.

The Chitralis would hate Skunk, I'm sure.


As a mitigating factor, I would add that I only got back a few hours ago from a long (nearly 24 hrs) series of flights, and I'm jet-lagged and tired (I can never seem to sleep on planes - economy class syndrome, I guess), and also slightly hyped. Hence the somewhat disjointed and sometimes tangential ramblings. Sorry. :)