Cannabis and Psychosis

Psychosis is the new demon in 100 years of propaganda which has failed to convince us that cannabis use leads to murder, rape, prostitution, insanity, dwarfism, dwindling, idling, hard drugs, death and the 'assassination of youth'.

This article on the BBC site discusses the varied results of the research into the relationship between cannabis use and mental health.

You can see from the article that the researchers are digging deep to find something, and coming to fast conclusions; each equally rapidly criticised with new hypotheses.

They look at every aspect to find the connection, studying Swedish soldiers, students, teenagers and now genes. But it's not going to be easy, you have to have a lot of faith to keep looking when you come up against the kind of results that Australian researchers found:

"despite a steep rise in cannabis use among Australian teenagers over the past 30 years, there had been no rise in the prevalence of schizophrenia".

That's difficult to explain.


If you read through the BBC page linked above, you'll wonder how those geniuses at the UK Daily Mail can come up with lines like these:

'Recent studies suggest cannabis users are at least six times more likely than non-users to develop schizophrenia' (Daily Mail, February 26th 2003)

'Smoking cannabis almost doubles the risk of suffering mental illnesses such as schizophrenia' (Daily Mail, March 1st 2005)

'Cannabis drives psychosis surge'

'The number of children treated for mental problems linked to cannabis use has quadrupled since it was downgraded to a Class C drug'

(the last two are from the Daily Mail print edition, September 19th 2005)

If you look up the Bulletins of the International Association for Cannabis as Medicine (IACM), you'll find more research results which confound the prohibitionists. I've taken the liberty of lifting a couple direct -

Israelian scientists propose that the association between cannabis use and increased risk for schizophrenia that have been observed in recent studies from Sweden, the Netherlands, New Zealand, and Israel may not be causal. Several studies have reported an association between genes encoding the cannabinoid receptor and schizophrenia. The researchers write: "An alternative explanation of the association between cannabis use and schizophrenia might be that pathology of the cannabinoid system in schizophrenia patients is associated with both increased rates of cannabis use and increased risk for schizophrenia, without cannabis being a causal factor for schizophrenia."
(Source: Weiser M, Noy S. Dialogues Clin Neurosci. 2005;7(1):81-5.)

Hawaiian researchers investigated the question whether the onset of schizotypal symptoms in regular cannabis users preceded the onset of cannabis use or whether these symptoms followed cannabis use. Their study in a large sample of college students (N=189) found that these symptoms generally were present before the start of cannabis use, an observation that does not support the theses of a causal link between cannabis use and schizophrenia.
(Source: Schiffman J, et al. Psychiatry Res 2005;134(1):37-42)