Study finds cannabis linked to increased risks for teenagers

Research that combined the results of 11 studies has found an association (but not a causal link) between cannabis use and ‘low to moderate’ mental health issues and risks of suicide amongst teenagers.

It is still not certain whether cannabis use causes increased risks, or whether people at higher risk are more likely to use cannabis (as self medication or as an escape).

NZ Herald:  New study of 23,000 teen cannabis smokers confirms link to later mental health problems

Cannabis use during adolescence is linked to an increased risk of depression and suicidal behaviour in young adulthood, a new study has found.

But the level of increased risk of depression and suicidal thoughts and attempts found in United States study is only low to moderate. No link was found to anxiety.

The research combines the results of 11 separate studies published over the past 15 years that together included more than 23,000 adolescent cannabis smokers and assessed their mental health when aged 18 to 32. People with prior depression were excluded.

“This review both confirms and reinforces findings from the research literature on the adverse psychological effects of regular cannabis use by mid- to late adolescents,” said Dr Joe Boden, the deputy director of the University of Otago’s Christchurch long-term health and development study.

“The findings of this [US] study further reinforce our concerns about the public health implications of any changes we may choose to make to cannabis laws in New Zealand,” Boden told the Science Media Centre.

Boden has written previously that there is growing evidence that regular or heavy use of cannabis may increase risks of: mental health problems, other forms of illicit drug use, dropping out of school and educational underachievement, and car crashes and injuries.

The new study, published in the Journal of the American Medical Association, does not state how much cannabis the research participants smoked, which is considered a significant omission.

And the study type could not show causal links. British experts have pointed out that as well as cannabis possibly affecting later mental health, it is plausible that people prone to mental health problems are more likely to smoke cannabis.

Dr Lindsey Hines, of the University of Bristol, said it was already known that using cannabis coincided with anxiety, depression and self-harm in teenagers.

While the US study suggested a link between early cannabis use and later issues, “we don’t know if cannabis use as a teenager is causing these adult mental health problems.

“It could be that these behaviours are all due to shared underlying risk factors, such as early adversity or genetics.”

Professor Sir Robin Murray, a psychiatry researcher at King’s College London, said that although the modest risk increase found in the US study was probably real, better-quality studies had found cannabis use increased the risk of schizophrenia-like psychosis more than the risk of depression or anxiety.

He also noted limitations in the US study, including that the researchers had not specified the quantity or type of cannabis smoked.

So this new super-study adds to the information available, but leaves a lot of questions unanswered.

Risks to teenagers of alcohol use is a reason that alcohol sales are restricted to those under 18.

It should also be noted that many teenagers are already using cannabis, so whether cannabis is decriminalised or not needs to consider whether that would increase (or decrease) cannabis use amongst teenagers.

And any drug is potentially harmful to people of any age – as well as being potentially beneficial ib some circumstances.

 

35 Comments

  1. Finbaar Rustle

     /  February 14, 2019

    “So this new super-study adds to the information available,
    but leaves a lot of questions unanswered.”
    An apt description of any article on any subject including
    economy, trade, international relations, climate change, environment,
    housing, employment, health, education.
    So the gurus of research don’t know, the politicians and media spin everything
    according to what their target audiences want to hear and
    Joe and Joanne public do what feels right at the time.
    She’ll be right sheeples 🙂

    • NOEL

       /  February 14, 2019

      Cannabis science is where tobacco science was 40 years ago.
      I’d put money on science 20 years down the road suggesting legalizing might not have been a good idea.

      • Duker

         /  February 14, 2019

        Absolutely No comparison. Im not in favour of legalising marijuana but the health risks of tobacco were known to be enormous 60 years ie 1960s
        Normally some thing that is unhealthy will be banned at a ‘risk rating ‘ of 3 , where 0 is neither harm or benefit.
        Tobacco was even in the early days, a risk rating of 30 from long term use.

        • David in aus

           /  February 14, 2019

          3 joints are equivalent to 20 cigarettes in terms of cancer causing agents. People know about lung cancer and cannabis, the concern is about mental health.

      • Griff.

         /  February 14, 2019

  2. Corky

     /  February 14, 2019

    ”Research that combined the results of 11 studies has found an association (but not a causal link) between cannabis use and ‘low to moderate’ mental health issues and risks of suicide amongst teenagers”

    From my experience the causal link has been established as far as I’m concerned.

    I watched Dr Phil gave a short presentation about how weed basically stuffs the minds of teenagers up. Not that I needed it, but I think there are too many people looking at studies, and not actual street experience.

    • Duker

       /  February 14, 2019

      Thats what ‘studies’ do . look at people in the care of mental health agencies and ask about their drug use.
      I know of people who smoke ‘every day’ and have ‘no mental health’ issues early on , its the stroke at 48 that gets them.

      • Griff.

         /  February 14, 2019

        How many chronic pot smokers do you know ?
        1,000 or so ?
        Because that is a level of risk you are pushing with your hyperbole.
        I would guess that in reality you know someone who smoked and had a stroke.
        Well I knew someone who drunk and had a stroke at 50. .
        Except I am smart enough to know in the real world that is not evidence.
        I also knew four who drunk and died very young as a direct result.
        I can also give a huge amount of independent evidence from multiple sources that alcohol is the worst drug for killing our youth by far .

        Cannabis is destructive to young minds
        The black market makes no effort to restrict its access to the young .
        In fact it markets to them and uses kids to sell it because under the prohibition laws they do not go to jail if caught.
        It has been easier for kids to get pot than alcohol and ciggys since at lest the seventy’s because cannabis is unregulated.

        The only way to keep cannabis away from the young is to make it legal and place an age restriction on it .
        In legal markets the youth usage is declining.

        Legalize, regulate, tax and educate .

        • Duker

           /  February 14, 2019

          Same mantra used by alcohol industry…. Legalize, regulate, tax and educate .

          while the consumption per head is declining, the hard core of heavy drinkers is drinking more – as of course these people are the real customers that a legalised industry looks after. Marijuana will be the same.
          When I lived in big city in Australia, in an area with drug and alcohol problems, the bottleshops had one product in big stacks by the door – cheap cask wine

          • Blazer

             /  February 14, 2019

            ‘ cheap cask wine’…a.k.a…’solo mothers …handbag’.😁

  3. PartisanZ

     /  February 14, 2019

    Got ourselves in a right old bind here eh?

    Ideally the legal age for cannabis consumption other than bona-fide medicinal would be 21 or 25 years old … but the (much more damaging than any other substance) LIQUOR INDUSTRY has trumped (and pimped) common sense already with their legal age of 18 …

    What do you do?

    Add to that the double bind of where we’ve gotten to with tobacco …

    Expect a steady release of negative studies leading up to the referendum … in support of Family First and Christian Conservatives and The Right Brigade …

    Never mind about the something like 25,000 positive studies …

    • Duker

       /  February 14, 2019

      Yes alcohol has pimped itself up. So we want to go down the same road with another addictive substance to poke a finger in the eye of the alcohol industry?
      facts are beyond your comprehension, so just stick to hyperbole and dumb nonsense

      • Griff.

         /  February 14, 2019

        Yes alcohol has pimped itself up. So we want to go down the same road with another addictive substance

        Ah yes the idiotic dont legalize cannabis because it will result in people using it nonsense.
        Cannabis is already readily available in NZ in case you did not know.
        Prohibition has done nothing to restrict its usage. We already have one of the highest usage rates in the west.

        The addictive card.
        Cannabis is no where near as additive as common legally available drugs like coffee alcohol or nicotine.

        facts are beyond your comprehension, so just stick to hyperbole and dumb nonsense
        Yes indeed………

        • Duker

           /  February 14, 2019

          Thats because we have done mostly nothing to restrict its usage, compare with Tobacco where the harm minimization goal is its elimination.

          • Griff.

             /  February 14, 2019

            Thats because we have done mostly nothing to restrict its usage, compare with Tobacco

            ROFL
            You really are living in Lala land mate.

            What Police are doing about cannabis

            Police are committed to reducing the demand for cannabis and disrupting the supply chain. Each year Police target the people who grow and supply cannabis, through aerial searches throughout New Zealand. Crops are seized and destroyed. Police can also seize assets and cash that have been obtained through the supply of cannabis.
            Cannabis laws and penalties

            Penalties associated with cannabis range from a $500 fine for possession to a 14 year jail term for its supply or manufacture.

            Cultivation of cannabis, including to sow or plant it, can, on indictment, result in a 7 year jail term or an immediate 2 years jail term and/or $2,000 fine (depending on the amount).

            Never argue with stupid people, they will drag you down to their level and then beat you with experience.” -Mark Twain

            • phantom snowflake

               /  February 14, 2019

              Yep and partly as a result of NZ Police’s ongoing War On Cannabis, methamphetamine is now more readily available than Cannabis in many parts of NZ. Slow clap.

        • PartisanZ

           /  February 14, 2019

          The Conservative mindset is strong on here today …

          Couldn’t have said it better myself Griff.

    • Mother

       /  February 14, 2019

      This is where my message rings true –

      Individuals, individuals individuals.

      What is the most important thing in the world? It is not people, it is not people, it is not people.

      The most important thing for any people is for the individual to be free.

      Alcohol hurt the Maori, yet it’s too late to take it away.

      Only Christianity, from the minds of individuals, delivers a system politically in which we can grow as a people.

  4. Blazer

     /  February 14, 2019

    👀….as they say…I’ll get the…pop corn!

  5. david in aus

     /  February 14, 2019

    Wants to legalize cannabis but ban high-Calorie food. Is NZ confused?

    Is Mental Health problems and high rates of suicide in Maori related to cannabis use? Maori use cannabis at epidemic rates. Perhaps, if we legalize cannabis, we should tax it heavily to pay for mental health costs.

    http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10349472

    • Gezza

       /  February 14, 2019

      You comment about mental health and suicide but post a link suggesting cannabis might be responsible for high rates of lung cancer?

      • david in aus

         /  February 14, 2019

        The link was there to link Maori and high rates of cannabis use.
        The association of Mental Health and Cannabis is in Pete’s post.

        Correlation is not causation. Saying that we know that cannabis does affect mental health in some people. Therefore the correlation is plausible for causation.

        Although I am skeptical of legalizing cannabis, we cannot say it is causative for higher rates of depression and suicide, definitively yet. Perhaps in the next five years, we should be seeing evidence from countries and states that have legalized its use.

        • david in aus

           /  February 14, 2019

          Those States in America have provided a near perfect experiment. We would have to thank them for using their people as guinea pigs.

  6. duperez

     /  February 14, 2019

    There’s no doubt problems with young people from cannabis will increase after access is freed up. No worries though, it’ll be the job of teachers and schools to handle the consequences.

  7. Sunny

     /  February 14, 2019

    Simon Bridges and Paula Bennett have both been asked if they have ever smoked cannabis. Has the same been asked of Jacinda Ardern and Winston Peters and their offsiders?

    • PartisanZ

       /  February 14, 2019

      FFS … Who cares!!!???

      • Sunny

         /  February 14, 2019

        “FFS …. Who cares?/???!!! ” Well apparently the media thought we cared, because they asked Bridges, and Bennett. So why haven’t they asked both sides?

        • Gezza

           /  February 14, 2019

          Good point. I couldn’t find anything with a quick google search suggesting either of them have ever been asked, or ever said whether they’ve tried cannabis. But it was a very quick search.

        • Griff.

           /  February 14, 2019

          It is about hypocrisy.
          If you are against legalization and you smoked it even once take your self off to the local police station and ask them to arrest you for possession, go to court plead guilty and do the time /pay the fine, take the mark on your record that stops you getting some jobs,travailing and will haunt you in other ways for the rest of your life .
          Because that is what you are trying to inflict on others for something you have done.

  8. Zedd

     /  February 14, 2019

    This just reaffirms that teenagers (<18) should not use cannabis or other mind altering drugs.. just as they should not drink booze.

    Most of these reports, work on the extreme views: about 10% of people who use cannabis have negative issues.. is this a reason to stop the other 90% who dont suffer these problems ?
    NO.. offer help to the 10% !

    Many more people are harmed by booze & ciggies, but I dont hear all the prohibitionist rhetoric about them. Because: the authorities KNOW it does NOT work.

    Prohibition stops many folks who have these problems seeking help, for fear of being arrested.

    Time to remove the blinkers & cut out all the double-standards 😦

    I wonder who is funding this 'research' ??
    follow the money :/

    • Trevors_elbow

       /  February 14, 2019

      I tend to agree Zedd…age restricted, legalised supply with a good tax component ring fenced for mental health treatment for the inevitable impacts on those suspectible to pyschocis of various types that ganga use can trigger…

    • Zedd

       /  February 14, 2019

      The thing they often exclude in these reports, is that Cannabis is usually sold through the black-market & the dealers do not ask for age ID.. unlike a regulated Alcohol market, which is R18+

      They will never get rid of the black-market, but Prohibition actually promotes it & does almost nothing to actually prevent illegal drug use 😦

      • Griff.

         /  February 14, 2019

        In the police report on drug harm they quantified all the costs on society of cannabis use..
        It come out to something like $450,000,000 a year most of it directly attributable not to the drug itself but to the policy of prohibition.

        • Yes the so-called, outdated ‘DRUG-harm index’ is largely based around the funds WASTED on maintaining Prohibition !

          I saw a recent news item that stated (paraphrased) ‘The majority of people busted for illegal drugs.. will continue to ‘Reoffend’ on an ongoing basis’ meaning the WAR on DRUGS, is a total waste of time/resources. The only thing it really does; Keeps a large number of Police/Judges/Prisons/lawyers etc. ‘gainfully employed’.. meanwhile it is Prohibition, that harms the majority of those ‘processed through the criminal justice system’; often for possession or small time ‘social dealing’ (friends/whanau). Who often lose employment opportunity & overseas travel options, as a result !

          For those who do get a prison term.. they often come out as ‘better criminals’.. having mixed with the REAL ‘hardcore crims’ inside.. REAL SMART move ?! 😦

          enuf sed 😦

  9. patu

     /  February 14, 2019

    Hmmm… I find it interesting when so called academics give an allegedly informed opinion on cannabis. When I was a teenager, it was FAR easier to score a tinny than it was to buy a dozen beers. It still is now, except a tinny now comes in a plastic bag, & is half the size of what it was 25 years ago. Might even be laced with ‘synnies’, if one doesn’t have a reputable supplier…