Study Debunks Claim That Pot Smoking Causes Mental Illness

By chillinwill · Jul 2, 2009 · ·
  1. chillinwill
    Much has made — by the mainstream media and others — of the claim that cannabis use causes certain types of mental illness, specifically schizophrenia and psychosis.

    Most notably perhaps, a team of researchers writing in the July 28, 2007 edition of the prestigious scientific journal The Lancet, boldly proclaimed that smoking cannabis could boost one’s risk of a psychotic episode by 40 percent or more.

    Naturally, this alarmist rhetoric received wall-to-wall coverage by the mainstream press. Even more troubling, the supposed ‘pot-and-schizophrenia’ link was one of the primary reasons cited by British PM Gordon Brown, ex-Home Secretary Jacqui Smith and others as the impetus for reclassifying cannabis (from a verbal warning to a criminal offense punishable by up to five years in jail) in the United Kingdom.

    Of course, there was a fatal flaw with The Lancet’s argument — one that, oddly enough, every single MSM outlet failed to mention. Empirical data did not support the investigators’ hypothesis that smoking marijuana was associated with increased rates of schizophrenia or other mental illnesses among the general public — a fact that even the authors begrudgingly admitted when they declared, “Projected trends for schizophrenia incidence have not paralleled trends in cannabis use over time.”

    Which brings us to 2009.

    Two years after The Lancet’s dire predictions, a team of researchers at the Keele University Medical School have once and for all put the ‘pot-and-mental illness’ claims to the test. Writing in a forthcoming edition of the scientific journal Schizophrenia Research, they compare long-term trends in marijuana use and incidences of schizophrenia and/or psychoses in the United Kingdom. And what do they find?

    “The expected rise in diagnoses of schizophrenia and psychoses did not occur over a 10 year period. This study does not therefore support the specific causal link between cannabis use and incidence of psychotic disorders. … This concurs with other reports indicating that increases in population cannabis use have not been followed by increases in psychotic incidence.”

    Should we expect an apology — or even better, a change in policy — from the Gordon Brown regime any time soon? Or at the very least, will some sort of ‘correction’ be forthcoming from the mainstream news media?

    I wouldn’t hold my breath.

    By: Paul Armentano
    July 1st, 2009
    Norml Blog

    Share This Article


  1. Alfa
    Please add the related study to the document archiv.
  2. Greenport
    SwiM would really like to see data/charts comparing schizophrenia rate to marijuana use rate.

    In any case though, the true data isn't going to come out for quite some time now because we need to document the relation of frequent marijuana use over time with schizophrenia and other diseases people believe it may be associated with.

    Does smoking pot every day for 40 years cause any effect on that person's psychological health? In swiM's opinion this question is still not answered...
  3. Jatelka
To make a comment simply sign up and become a member!