New Study: Cannabis 'can cause psychosis in healthy people'

By chillinwill · Jul 28, 2009 · ·
  1. chillinwill
    The results appear to confirm a link between psychosis and skunk cannabis, which now accounts for 80 per cent of street seizures of the drug.

    Scientists at the Institute of Psychiatry in King's College London made the discovery after running tests on 22 healthy men, aged in their late 20s.

    They injected them with THC - a major component of skunk cannabis which has been blamed for increasing psychosis among heavy users.

    By giving a dummy injection to some, and a dose of THC to others, the scientists were able to establish a link between THC and psychosis, in which hallucinations and delusions leave sufferers unable to tell between the real and imagined.

    The team, led by Dr Paul Morrison, concluded: "These findings confirm that THC can induce a transient acute psychological reaction in psychiatrically well individuals."

    The researchers found that the "extent of psychotic reaction" was not related to "the degree of anxiety or congnitive impairtment" in the men.

    Mary Brett, vice president of Europe Against Drugs, said: "This shows that anyone who is healthy can become psychotic by smoking cannabis. They don't already have to have a mental illness. Healthy people can become psychotic."

    The potency of skunk cannabis has increased from six per cent THC - or Delta-9-tetrahydrocannabinol - content in 1995 to 14 per cent in 2005, and has been linked to increased instances of psychosis, particularly among young men.

    Today's skunk cannabis also contains virtually no traces of another chemical, called CBD (cannabidiol), which appears to counteract the damaging effects of THC.

    The research is the first time that the dangers of skunk cannabis have been tested in the UK. Previous experiments have been run by experts in the US, Holland and Brazil.

    Dr Morrison said the findings offered "additional evidence that can elicit temporary psychotic-like effects in some people", but stopped short of suggesting they proved a direct link between psychosis and THC.

    He said: "Much more research is needed to clarify if skunk is actually more harmful than traditional cannabis." More work needed to be carried out on the beneficial effects of CBD in balancing the damaging results of THC.

    Earlier this year then-Home Secretary Jacqui Smith restored cannabis from class C to class B status after concerns about adverse health effects, against the advice of her drugs advisers.

    Last year The Daily Telegraph revealed how a BBC reporter Nicky Taylor was injected with THC at the institute. One source who witnessed the effects on Miss Taylor said the effect was "dramatic, it was unpleasant".

    A survey of 200 users, published in July 2008, found that those who smoked skunk cannabis were 18 times more likely to develop psychosis than those who smoke milder forms of the drug.

    A Home Office spokesman said: "We have always been clear that cannabis is a harmful drug which should not be taken. Its use can lead to physical and psychological harms, and the mental health effects of cannabis use are real and significant.

    "We are taking comprehensive action to tackle cannabis use, from increased enforcement to reduce the supply, along with effective education and early intervention for those most at risk."

    By Christopher Hope
    July 27, 2009

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  1. Jatelka
    For those that are interested, Gradient has kindly uploaded the paper this story refers to here
  2. runitsthepolice
    According to the DEA:

    [FONT=Arial, Helvetica, sans-serif][SIZE=-1]Marinol (synthetic THC) has been studied and approved by the medical community and the Food and Drug Administration (FDA), the nation's watchdog over unsafe and harmful food and drug products. Since the passage of the 1906 Pure Food and Drug Act, any drug that is marketed in the United States must undergo rigorous scientific testing. The approval process mandated by this act ensures that claims of safety and therapeutic value are supported by clinical evidence and keeps unsafe, ineffective and dangerous drugs off the market.[/SIZE][/FONT]

    This is the same stuff that the article claims was injected into people, it "can induce a transient acute psychological reaction", and it is "a harmful drug which should not be taken."

    Someone is lying.

    Basically what the study says is that THC gets you high temporarily. The part about it being bad for you is obviously not true though because THC is an FDA approved medicine. WTF?!?!?
  3. Nature Boy
    THC is very rarely, if ever, found on its own in the type of cannabis people smoke. To say that cannabis can then cause psychosis in the average person is then misleading. At least the article highlights the importance of CBD which at least shows that they understand where the real problem lies. Even strains with a very high percentage of THC won't cause psychosis if enough CBD is present. Examining the effects of THC on its own is like injecting people with ethanol compared to having them sample a few glasses of wine.
  4. Master_Khan
    Bob Dylan is morally opposed to all these "findings and studies" which attempt to create the semantic illusion that there is a new 'reefer madness' caused by 'skunk' cannabis. Please correct Bob if he is wrong, but skunk is just very potent pot, eh? Not some new animal.
  5. Matthijs85
    This news article is quite misleading in my opinion.
    The news article suggests that THC causes a psychosis, while the paper actually measures that people who are injected with THC have more symptoms of psychosis while they are high. This is not so surprising to me, as THC has hallucinogenic properties. This does not say anything about the chances of getting a psychosis due to administering THC (although I believe it increases the risk).
  6. Alias: V
    I don't see how these findings confirm anything. They injected 22 people with THC. I want to know how they can compare this with the millions of people who smoke pot everyday with no signs of psychosis whatsoever. It's a reaction to the good publicity Marijuana has been getting recently. I thought we were moving past the obvious distortions of truth and utter lies that failed so thoroughly in the past.
  7. blahaha
    Uh yeah, they're injecting people with THC. They aren't psychotic, they're probably just really high. I've never heard of anyone injecting THC before. Not only that, but that's THC alone. Pot has many more chemicals in it that could counter the THC. CBD or whatever like someone said before me.
  8. Pumpkin
    I didnt read the whole paper but i did see where it said they injected them with doses of 2.5 mg THC. now im sure, like most anything i can think of, THC has more bioavailability intravenously. How is that compared to smoked mj? 2.5mg seems like a very low dose even if its i.v.
    Also marinol is THC dissolved in sesame oil i believe. So an i.v. of THC has to be dissolved in some kind of oil to be shot up correct? That cant be safe rite?

    Additionally all these findings are based on just 22 people all roughly the same age. Which makes it more skeptical in my opinion
  9. EscapeDummy
    The sad part is that 75% of people who read this won't get past the title.
  10. Senor Gribson
    "THC can induce a transient acute psychological reaction in psychiatrically well individuals."

    Or in layman's terms, weed gets you high.
    This is what they're giving out doctorates for nowadays?
  11. beizebopp
    SWIM has heard a few stories of psychosis from THC before. Recently a SWIfriend informed swim that someone he knew had attempted suicide after taking huge doses of synthetic THC regularly. SWIM agrees with SWInatureboy that marijuana and THC should not be treated as one and the same. SWIM thinks that the mix of different cannibinoids in cannabis strains is very important in keeping it safe, and that isolating THC on its own is not a wise move.
  12. el burgo
    What a load of shite

    el burgo added 0 Minutes and 34 Seconds later...

    Scare tactics
  13. cannabis-sam
    Well I do believe this article is misleading. But I do believe the study is sound as this part of the article suggests.

    I can see this study as a jigsaw piece in getting to the bottom of weather or not cannabis is a causal factor in the development of mental illness. What I do find to be a problem is that studies like this which are scientifically sound, are presented by the media as conclusive evidence.

    If I go off topic for a second, if anyone remembers the MMR (measels, mumps ruebella vaccine) scare. A doctor had quite innocentely done a certain type of case study (forget what it's called) on about 10 patients and noted that some of the cases he'd seen had developed autism after having the MMR jab. This doctor hadn't intended this study to be used as evidence that MMR was a causal factor in the development of autism. Yet it was picked up by the media, and out came the headlines "MMR linked to autism" which envoked fear in the population and led to many people not having a beneficial jab.
    This is one example of where the media completely twisted what was actually reported and used it to sell papers and on a bigger level sell fear.

    With cannabis the same thing seems to of happened, all the reports are not saying "we have proven cannabis causes mental health problems" actually what they are saying is "There is a link between cannabis and psychotic symptoms, but the evidence is far from substantial enough to say beyond all reasonable doubt cannabis causes these issues"

    The problem with the media lies in people being lazy, many of us here at drugs-forum are happy to read through the report (as I just did) and make their own rational conclusions. However the general population just wants things in an easy to read format, they want there information spoon fed to them without really caring how factual it is.

    To be fair to the papers many of them actually havn't said there's conclusive evidence on the matter but they've worded it in such a way many will just put two and two together in their own heads. When a paper says xyz is linked to xyz people assume "linked" means proven and this is just not the case.

    The study also suggests that the effects of THC resemble that of psychosis but it does not show that cannabis causes the onset of the actual illness, but it mimics the symptoms. (of course that's my understanding of it, what with me not being a scientist there were bits that went straight over my head but I think I got the jyst of it)
  14. Holyweed
    marijuana is like chicken egg, some people say they are bad, others say they are not. But the truth is that if it was that bad like some say, everyone would already be screwed up...and I bet this is just another study on which they give subjects 1kg of THC and then conclude that cannabis is harmful.
  15. Subvert
    SWIM knows a guy who had episodes of schizophrenia after smoking green everyday for years and relapsed into psychosis after falling back into his old ways,
    However he was most likely just vulnerable to psychosis and had a history of depression for which he used cannabis to self-medicate.

    The majority of smokers SWIM used to associate with at worst experienced some mild paranoia after a heavy session and managed to maintain a relatively normal lifestyle (could hold down a job, relationships, etc with no real problems).

    Personally SWIM found alcohol to be far more destructive,
    And will be going to Amsterdam next year to indulge and take a cruise down the canal. :)
  16. Amnesia
    Two of the main problems with reports like this is they are (1) dumbed down by the media (2) sensationalized to sell papers/pull in viewers (3) the media, and unfortunately a lot of people, believe psychosis and psychopathy are one and the same.

    The DSM IV criteria (the 'manual' for diagnosing mental health problems) clearly states that psychopathy is an unrelenting personality disorder - an illness in its own right. Psychosis, on the other hand is a symptom of an illness and is comprised of one or more of the following:
    1. Delusions
    2. Hallucinations
    3. Catatonic behaviour
    4. Thought disorder

    In terms of cannabis use, the user can become temporarily (hence the use of the word 'transient' in the above report) and mildly psychotic even with minimal amounts, but this in no way means they have developed a mental illness. The following are examples that SWIM has witnessed in her friends, and all of which wore off within an hour or so:
    1. Delusions - specific paranoias ("That painting is going to get me!"), believing that the user may die or is dying.
    2. Hallucinations - colours being more vibrant, sounds being deeper/fuller/richer, hearing music in the distance.
    3. Catatonic behaviour - never witnessed with cannabis use. Rare even in the most severe mental illnesses.
    4. Thought disorder - people talking apparent gibberish which they think makes sense. Only observed once in a cannabis user who had also drunk a lot of alcohol.

    In SWIM's opinion these 'psychotic' features are so mild they barely deserve the label of psychosis. In contrast, SWIM read a case study regarding a man in his mid 20s who suffered from schizophrinia . His hallucinations and delusions as he walked down the street were that every paving slab shattered and screamed as he stepped onto it, and then became the face of a demon which tried to bite his legs in order to drag him to hell.

    When assessing a person for a mental health problem based on the presentation of psychotic features, psychosis due to substance abuse is considered irrelevant unless it continues for a month after abstinence or the user has a previous history of severe mental health problems (such as schizophrenia or type 1 bi-polar disorder).

    Just a thought, something which has been bugging SWIM for sometime - the prevalence of severe mental health problems seem to have remained constant for at least the last 30-40 years (SWIM can't find figures older than these), which are:

    1% of the population suffer from schizophrenia
    1-2% of the population suffer from type 1 bi-polar disorder

    Both illnesses have recently been shown to have a genetic basis which means a person must have been born with the defective genes and, therefore, be genetically predisposed to the illness - both of which can be triggered in people who have never used drugs by incidents such as stress, bereavement, psychological trauma etc.
    If the increased strength of 'modern' cannabis i.e. skunk, causes these severe psychotic illnesses, and is also the most popular recreational drug, why haven't these figures increased?
    If there are any reports out there that show evidence of this SWIM would appreciate the links/references.

    Sorry if the above was a little disjointed and long :-
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