I mean, get real: Considering modern rates of usage, if cannabis really produced psychosis, the streets would be choked with a gibbering throng of burned-out potheads. It doesn’t. They aren’t.
“I’ve said it for years now,” film director John Holowach, responsible for the documentary High: The True Tale of American Marijuana, told Toke Signals. “If pot and mental illness were linked, the two should rise and fall with one another, but they don’t.”
And it’s not “merely anecdotal” evidence that says so. Widespread marijuana use by the public has not been followed by a proportional rise in diagnoses of schizophrenia or psychosis, according to the findings of a study in the scientific journal Schizophrenia Research.
Thus, the findings of a 2010 study published in the Archives of General Psychiatry alleging that smoking marijuana can “double” the risk of psychosis or schizophrenia are in conflict with previous reviews and ought to be interpreted with caution, according to Paul Armentano, deputy director of the National Organization for the Reform of Marijuana Laws (NORML).
“Despite claims that marijuana use may play a causal role in diagnosed incidences of schizophrenia, there exists no empirical evidence anywhere on Earth indicating that populations which have experienced rising rates of cannabis use have also experienced a parallel increase in rates of mental illness,” Armentano said.The 2009 systematic review published in Schizophrenia Research compared trends in marijuana use and incidences of schizophrenia in the United Kingdom from 1996 to 2005.
Researchers reported that the “incidence and prevalence of schizophrenia and psychoses were either stable or declining” during this period, even as the use of cannabis among the general population was rising.
The authors concluded that an expected rise in diagnoses of schizophrenia and psychoses did not occur over the decade under study. “This study does not therefore support the … link between cannabis use and incidence of psychotic disorders,” the study concludes, adding “This concurs with other reports indicating that increases in population cannabis use have not been followed by increases in psychotic incidence.”
The results of another clinical trial published in 2009 indicate that the recreational use of marijuana does not affect brain chemistry in a way that is consistent with the development of schizophrenia.
Armentano said that a non-causal association likely exists between marijuana use and psychosis because the symptoms of mental illness often strike early in life — at a time when young people are likely to be experimenting with cannabis.He also speculated that some people diagnosed with psychiatric disorders might be turning to marijuana after the onset of symptoms as a form of self-medication. Studies have shown many schizophrenics report that cannabis relieves their symptoms.
Ultimately, however, Armentano said that even if the concerns about the potentially adverse mental effect of marijuana use are to be taken at face value, then such findings support a policy of cannabis legalization and regulation — not criminal prohibition.
“Health risks connected with pot use — when scientifically documented — should not be seen as legitimate reasons for prohibition, but instead, as reasons for the plant’s legal regulation,” Armentano said.“For example, we as a society don’t regulate the production, use and sale of alcohol because it is innocuous, but rather because we acknowledge that its consumption, in some situations, may pose a risk of harm,” Armentano said.
”Placed in this context, today’s latest warnings do little to advance the government’s position in favor of tightening prohibition, and provide ample ammunition to wage for its repeal,” Armentano said.
Which makes all the more tragic the real-world consequences of tabloid-style Reefer Madness hysteria. Amidst a spate of breathless tabloid froth hyping the supposed dire threat from “Skunk,” a potent pot strain, British lawmakers in 2008 stiffened cannabis laws in the U.K.
A team of researchers had fanned the flames in the July 28, 2007 issue of prestigious scientific journal The Lancet, proclaiming that smoking marijuana could boost one’s risk of a “psychotic episode” by 40 percent or more.
In one fell swoop marijuana possession was reclassified from a verbal warning to a criminal offense punishable by up to five years in prison. British Prime Minister Gordon Brown, ex-Home Secretary Jacqui Smith, and others cited the supposed ‘pot-schizophrenia link’ as a major reason for the giant step backward.