The research by the University of Bristol was:
not about cannabis, smoking or schizophrenia. Rather it is about an artificial compound that is not present in cannabis, which was injected into rats, and which led to changes in their brain waves.
The original article was deconstructed by Neurobonkers.
The leader of the research, Dr Matt Jones, was reported to have said:
“The study does NOT show that one spliff will bring on schizophrenia.”
And the UKCIA (who complained to the PCC) noted:
I spoke to the PR department of Bristol University who were “angry” with the way the Daily Mail reported this study. The report is a work of fiction, totally and utterly baseless lies.
Today, the Mail has published a clarification:
A report on research by the University of Bristol on 26 October was headlined 'One cannabis joint "can bring on schizophrenia".' We are happy to clarify that, as the article explained, the research on rats found that the active ingredient in cannabis could induce symptoms similar to schizophrenia, rather than schizophrenia itself.
This statement raises several questions.
The Mail changed the headline of the online article some time ago. Despite that, it has taken them five months to publish this clarification. 'Happy to clarify' indeed.
In addition, the clarification makes it sound as if there was only a problem with the headline. The article - which remains live - begins:
Smoking just one cannabis joint can bring on symptoms of schizophrenia, a study has found.
Researchers at the University of Bristol have, for the first time, looked in detail at the changes in the brains of cannabis users.
The study did not 'find' this - no joints were smoked - and it was actually the brains of rats, not cannabis users, that were tested.
The clarification also refers to the researchers using 'the active ingredient in cannabis'. In fact, they used an artificial compound called CP55940 which:
mimics the effects of naturally occurring THC (one of the psychoactive compounds found in marijuana).
As Neurobonkers states:
The study did not use cannabis or any chemical present in cannabis.
Neurobonkers has complained to the PCC - will the Mail's clarification need further clarification?