Ottawa Citizen's Margret Kopal on Marijuana and Schizophrenia

Here is Margret Kopala quoting approvedly from the Indpendent --- the same paper that right wingers like to "Fisk" http://www.canada.com/ottawacitizen/news/story.html?id=16359999-767a-40cb-b854-a70c9c79f861&p=1

"Record numbers of teenagers are requiring drug treatment as a result of smoking skunk, the highly potent cannabis strain that is 25 times stronger than resin sold a decade ago."

The Guardian rebutted such nonsense in its Bad Science column.

There is exceptionally strong cannabis to be found in some parts of the UK market today: but there always has been. The UN Drug Control Programme has detailed vintage data for the UK online. In 1975 the LGC analysed 50 seized samples of herbal cannabis: 10 were from Thailand, with an average potency of 7.8%, the highest 17%. In 1975 they analysed 11 samples of seized resin, six from Morocco, average strength 9%, with a range from 4% to 16%.
To get their scare figure, the Independent compared the worst cannabis from the past with the best cannabis of today. But you could have cooked the books the same way 30 years ago: in 1975 the weakest herbal cannabis analysed was 0.2%; in 1978 the strongest was 12%. Oh my god: in just three years herbal cannabis has become 60 times stronger.”

http://www.guardian.co.uk/drugs/Story/0,,2041749,00.html

Margret Kopala “Addiction magazine predicted that a quarter of new cases of schizophrenia by 2010 will result from cannabis smoking.”

The logical implication of this kind of reasoning is that as marijuana use increases so should the number of cases of schizophrenia. However, there are no epidemiological studies suggesting this is true. On the contrary, a New Zealand study found that there has been no spike in the number of people diagnosed with schizophrenia despite a large increase in marijuana use in that country. An American study similarly found no such correlation.

Maia Szalavitz summarizes in Salon. “Perhaps the strongest piece of evidence to cast doubt on a causal connection between marijuana and schizophrenia is a long flat-line trend in the disease. While marijuana use rose from virtually nil in the 1940s and '50s to a peak period of use in 1979 -- when some 60 percent of high school seniors had tried it -- schizophrenia rates remained virtually constant over those decades. The same remains true today: One percent or fewer people have schizophrenia, a rate consistent among populations around the world. This is in stark contrast to studies linking tobacco smoking with lung cancer, where rises in tobacco use were accompanied by rising rates of lung cancer.

"If anything, the studies seem to show a possible decline in schizophrenia from the '40s and the '50s," says Dr. Alan Brown, a professor of psychiatry and epidemiology at Columbia University. "If marijuana does have a causal role in schizophrenia, and that's still questionable, it may only play a role in a small percent of cases.”

For the tiny proportion of people who are at high risk for schizophrenia (those with a family history of the illness, for example), experts are united in thinking that marijuana could pose serious danger. For those susceptible, smoking marijuana could determine when their first psychotic episode occurs, and how bad it gets. A study published in 2004 in the American Journal of Psychiatry of 122 patients admitted to a Dutch hospital for schizophrenia for the first time found that, at least in men, marijuana users had their first psychotic episode nearly seven years earlier than those who did not use the drug. Because the neurotransmitters affected by marijuana are in brain regions known to be important to schizophrenia, there is a plausible biological mechanism by which marijuana could harm people prone to the disorder. Both Brown and Carpenter say that people with schizophrenia who smoke pot tend to have longer and more frequent psychotic episodes, and find it very difficult to quit using the drug.”

http://dir.salon.com/story/news/feature/2005/09/19/reefer_madness/index.html?pn=1

It should also be pointed out that rates of alcoholism and drug abuse of all kinds are much higher in the schizophrenic population than in the general population and no one is claiming, for example, that alcohol abuse leads schizophrenia, indeed quite the opposite. The following explains the magnitude of the association.

“The Epidemiologic Catchment Area (ECA) study2 (2 The ECA study was a nationwide survey that used DSM–IV criteria to determine the prevalence of psychiatric disorders in the general population and among people in treatment.) found that 33.7 percent of people with a diagnosis of schizophrenia or schizophreniform disorder (a related disorder marked by the same symptoms as schizophrenia but lasting less than 6 months) also met the criteria for an AUD diagnosis at some time during their lives and that 47 percent met the criteria for any substance use disorder (excluding nicotine dependence) (Regier et al. 1990). Rates of substance use disorder tend to be higher among males and among people of both genders and all ages in institutional settings, such as hospitals, emergency rooms, jails, and homeless shelters. This holds true for people with and without schizophrenia (Regier et al. 1990).”

http://www.athealth.com/Consumer/disorders/schizophreniaalcohol.html

Margret Kopala “British rapper J-Rock, a rehabilitated skunk addict, told the Independent that "if you're on skunk and you have a confrontation with somebody, you feel almost untouchable."
"Skunk induced paranoia," the Independent concluded, "is behind the surge in violent crime." Remember, once you are psychotic, you don't need continued hits of marijuana to behave aggressively or to experience paranoia.”

If J-Rock says it is true, then it must be true. What utter dribble.
Anyway, this is what the US Department of Justice Department study found.

“Marijuana and opiates temporarily inhibit violent behavior, but withdrawal from opiate addiction tends to exaggerate both aggressive and defensive responses to provocations.”

The notion that “skunk induced paranoia” leads people to commit violent criminal acts is so laughably fucking stupid it hardly bears comment. Not even the Bush administration makes this claim.

By the way, this is what was said about alcohol and violence in that same article.

“For at least the last several decades, alcohol drinking--by the perpetrator of a crime, the victim, or both--has immediately preceded at least half of all violent events, including murders, in the samples studied by researchers.

Chronic drinkers are more likely than other people to have histories of violent behavior.”

http://www.druglibrary.org/schaffer/GOVPUBS/psycviol.htm

Update: CBC's the National

Mitch Earleywine a professor of psychology at the University of Southern California leveled an important methodological criticism against the New Zealand study referred to tonight in the CBC’s the National.

“Mr. Earleywine notes that Mr. Fergusson and his colleagues did not actually diagnose psychosis in the marijuana smokers they studied. Instead, they administered a short mental health questionnaire that asked if the respondent had ever experienced any of 10 "psychotic symptoms."

Some symptoms are clearly troubling, such as "hearing voices that other people do not hear" and having "the idea that someone else can control your thoughts." Others are not so obviously strange: feeling that other people cannot be trusted; feeling that you are being watched or talked about by others; never feeling close to a person; and having ideas and beliefs that others do not share.

Among 25-year-olds who had never smoked marijuana, the mean number of symptoms reported was 0.64. That number rose among those who smoked marijuana: Less-than-monthly users reported 0.89 symptoms, while daily marijuana smokers reported 1.95 symptoms. That rise, modest though it may be, is statistically significant.

But Mr. Earleywine believes there might be less here than meets the eye. In a letter to be published in the journal that published the study, Mr. Earleywine notes that it is fairly common for marijuana intoxication to cause feelings of paranoia, but the researchers "give no indication that respondents were asked to distinguish between feelings experienced while intoxicated and feelings experienced at other times. Thus, we are left with no clue as to whether these are long-term effects actually indicative of mental illness or simply the normal, passing effects of acute intoxication."
http://www.november.org/stayinfo/breaking3/MJScience.html