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    Cannabis and psychosis Archived Message

    Posted by Gerard on March 20, 2019, 11:07 am

    "Marta Di Forti and colleagues' retrospective case–control study1
    distinguished between self-reported use of high-potency (skunk) versus lower potency (hash) cannabis*. Scaremongering headlines in the media predictably followed. The Daily Mail screamed “Scientists show cannabis TRIPLES psychosis risk: Groundbreaking research blames ‘skunk’ for 1 in 4 of all new serious mental disorders.” Undoubtedly, politicians and policy makers who have already made up their minds about regulation of cannabis will seize on the study as support for their views.
    The authors must share some of the blame for misinterpretations of their results. They were pre-committed to causal language and failed to acknowledge important limitations of their study. An earlier report2
    by the authors concerning the same cases but not cited in the present one1
    declared “Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users”. The title of the present Article announces “psychosis attributable to use.” The abstract reports a “population attributable fraction”, with obvious interest to journalists and politicians who will not recognise the inferential leap. Population attributable fraction or risk is a term that should be reserved for associations for which causality has been more firmly established and appropriate caveats should indicate uncertainty about its applicability.3
    Both cases and controls were selected from South London. The area's distinctive character limits generalisability to other areas of the UK or the world. Cases and controls were poorly matched. Half of the cases were black individuals and only a third were white, with these proportions reversed among controls. There are also highly significant differences in gender, education, and ever being employed. Such differences cannot be overcome in analyses with inclusion of an incomplete selection of crudely measured control variables. Frequency of use of cannabis was established by retrospective self-report and the key distinction of skunk versus hash was not one that participants might be able to reliably make.
    Results could conceivably be explained by protopathic bias, with people who developed psychosis using cannabis or skunk to self-medicate early symptoms. Note the doubling of probability of psychosis for “never” as compared with “less than once a week”.1
    Confounding by indication 4
    is suggested by the profound disorientation that daily use of skunk entails and the likelihood that people who are not already dysfunctional would find it aversive and intolerable.
    Causal inferences from case–control studies are always hazardous, particularly with poor matching and incomplete specification and imprecise measurement of possible confounds. The unwanted influence of relevant group differences, whether measured or left unmeasured, might only be compounded by brute application of statistical controls. Awareness of the obvious political and policy implications of results, and the likely misuse to which they could be put, apparently failed to discourage the authors from inappropriate causal inferences and ignoring of obvious limitations of their study. This failure can only serve to distract readers from the important message concerning the need for a distinction between higher and lower potency forms of cannabis, even if it should be made with greater precision and in the context of a prospective study." https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366%2815%2900113-3/fulltext


    *Not great science even though I agree...certain types of hash like Nepalese Temple Ball and Gold Spot Moroccan are high in potency but the cannabinoid and cannabinols are balanced ..in both "skunk" and "haze" types (the former is indica predominant the latter sativa predominant), breeding for high THC content at the expense of the presence of the other balancing cannabinoids/cannibinols has created a triffid like hybrid which may (metaphorically speaking), "blind" the user.

    On Victoria Live DiForte stated that cannabis use cannot be identified as "sole cause" and that psychosis may affect more vulnerable individuals whose vulnerabilities cannot as yet be identified. None of the studies mentioned (one prev. was in Finland), mentioned the elevated adrenaline levels known to be present in cannabis users in states where cannabis is illegal! Such endocinal influences have been shown to be extremely significant, when I wrote a consultative document for the Legalise Cannabis Campaign in the mid-80s I studies the affect of decriminalisation in Amsterdam...research showed that regular users (residents not tourists), used less following decriminalisation, an explanation for this is the lower stress levels associated with cannabis use meaning that regular users (both recreationally and medicinally), need less cannabis especially as their adrenaline levels were less elevated.
    I use cannabis medicinally but eschew any hybrid I cannot verify as balanced, I don't use chemically "feminised" seed and almost never buy indigenously produced "home grown", preferring to buy in cannabis from known landrace strains grown and processed traditionally. Long term use of medicinal cannabis is far preferable for my chromic pain management than is the use of the opioid I am on repeat prescription for from my G.P!
    Both medicinal and recreational cannabis need to be produced by those with an understanding of the "permissions" involved when crossing this sacred plant for hybridisation purposes, this is the old law and is as relevant today as it ever was. The "permissions" are based on the genetic compatibilities of the strains involved..for instance one would not simply "rudely" cross an afghani indica with a Thai sativa..one would expect there to be a "diplomatic incident"! Instead one would gradually transition the plant as one would if one was on a questing pilgrimage oneself...It is time both the cannabis industry and those in conventional science who oppose cannabis legalisation removed their blinkers and truly realised the science involved...both patients and the wider community are suffering from the ignorance concerning not just cannabis but natural medicines generally as it stands..it's time people grew up and accepted the fact that mother nature has enormous amounts to teach us if we would only listen!

    #LegaliseCannabis

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