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Study exposes mental effects of pot

According to the New Scientist, there was hardly enough reliable evidence to support the idea that cannabis use could cause such mental illnesses until now. The lack of good evidence has delayed studies in finding harmful effects of a seemingly harmless drug.

One of the main conclusions of the research was that people who start smoking cannabis as young adults were at the greatest risk of later developing mental health problems. Another study done by an associated team concluded that depression and schizophrenia in the United Kingdom's population could be reduced by 13 percent if marijuana use was eradicated.

They concluded that regular marijuana use led to educational failure and unemployment, which could increase the risk of depression.

Researchers at King's College London, UK, analyzed continuous data taken on over 1000 people born in Dunedin, New Zealand in 1972 and 1973, and found that people who used cannabis by age 16 were four times as likely to have a diagnosis of schizophreniform disorder (a milder version of schizophrenia) at age 27 than those who didn't use the drug.

Another study done to see the drug's effects on the lungs was coupled with research done on the long-term mental effects of cannabis usage. According to the New Scientist, The British Lung Council concluded in a recent study that smoking marijuana was as bad if not worse than smoking cigarettes.

Furthermore, the cannabis produced and harvested now had been proven to be 10 to 12 times stronger than the trees smoked in the "flower-power' generation

By further examining marijuana joints, the scientists found that the tar from a joint contains concentrations of carcinogens benzathracenes and benzpyrenes up to 50 percent higher than tobacco smoke, and that THC, which is the most concentrated psychoactive ingredient of cannabis, destroys the immune system cells that help protect the lungs from infection.

Just a few parts of the article for those who want current stuff.

http://www.jhunewsletter.com/vnews/display.v/ART/2003/04/11/3e95e7d8a6ea7

Psychosis, Hype And Baloney

Although the mainstream media is eating it up, a new study claiming a link between marijuana use and psychosis should be approached with great caution.

As the month began, the worldwide press jumped all over a study in the March issue of the journal Addiction purporting to show a causal link between marijuana use and psychosis. "Drug Doubles Mental Health Risk," the BBC reported. "Marijuana Increases Risk of Psychosis," the Washington Times chimed in.

Such purported links have lately become the darling of prohibitionists, but a close look at the new study reveals gaping holes unmentioned in those definitive-sounding headlines.

Before we look at the study itself, let's consider some basics: If X causes Y, it's reasonable to expect a huge increase in X to cause at least a modest increase in Y, but this has not been the case with marijuana and psychosis. Private and government surveys have documented a massive increase in marijuana use, particularly by young people, during the 1960s and '70s, but no corresponding increase in psychosis was ever reported. This strongly suggests that if marijuana use plays any role in triggering psychosis, that effect is weak, rare, or both.

For this reason, researchers should approach "proof" that marijuana causes serious mental illness with great caution. The researchers in this case, a New Zealand team led by David M. Fergusson of the Christchurch School of Medicine and Health Sciences, seem to have done just the reverse.

Fergusson's team looked at a group of 1,265 New Zealand kids who were followed from birth to age 25 and assessed at various points along the way for a variety of physical, mental and social problems and issues. At ages 18, 21 and 25 they were assessed for both marijuana use and supposed psychotic symptoms. Having found a correlation with daily users reporting the highest frequency of psychotic symptoms, they then applied a series of mathematical models. These models are designed to adjust for possible variables that might confound the results and to assess whether the marijuana use caused the symptoms or vice versa.

Whatever model was applied, the correlation held up. But the reported "growing evidence" that "regular use of cannabis may increase risks of psychosis" depends completely on the validity of the underlying data, and those data raise some screamingly obvious questions.

Psychotic symptoms were measured using 10 items from something called Symptom Checklist 90. Participants were asked if they had certain ideas, feelings or beliefs that commonly accompany psychotic states. The researchers did not look at actual diagnoses, and the symptom checklist is not identical to the formal diagnostic criteria listed in the DSM-IV manual. Perhaps most important, they only used 10 "representative" items from a much larger questionnaire.

These 10 items focus heavily on paranoid thoughts or feelings, such as "feeling other people cannot be trusted," "feeling you are being watched or talked about by others," "having ideas or beliefs that others do not share." This presents a big methodological problem, because it is well known that paranoid feelings are a fairly common effect of being high on marijuana.

But the article gives no indication that respondents were asked to distinguish between feelings experienced while high and feelings experienced at other times. Thus, we are left with no indication at all as to whether these supposed psychotic symptoms are long-term effects or simply the normal, passing effects of marijuana intoxication. While it's possible the researchers had these data and didn't see a need to report them, the failure to do so is downright bizarre. It's like reporting that people who go to bars are more erratic drivers than people who don't, without bothering to look at whether they'd been drinking at the time their driving skills were assessed.

Even if these were long-term effects, the researchers seem not to have considered that what might be an indication of psychosis in other circumstances could be an entirely normal reaction for people who use marijuana. Consider: Someone using a substance that is both illegal and socially frowned-upon almost by definition has "ideas or beliefs that others do not share." This is not a sign of mental illness. It's a sign of a rational person realistically assessing his or her situation.

The same goes for "feeling other people cannot be trusted." Just ask Robin Prosser, the Montana medical marijuana patient arrested last summer on possession charges by the cops who came to save her life after she'd attempted suicide because she was in unbearable pain after running out of medicine.

Fergusson reports very little raw data, so we don't know which symptoms came up most often, or whether the differences in average levels of symptoms between users and non-users came from a few people having a lot of symptoms or a lot of people having a couple symptoms. The heavy-user group, with the highest levels of supposed psychosis, reported an average of less than two symptoms each. So it is entirely possible that the entire case for marijuana "causing" psychosis is based on marijuana smokers having the completely reasonable feelings that they have beliefs different from mainstream society and thus should be a tad suspicious of others.

"Proof" that marijuana makes you psychotic? No. Not even close. But don't expect the mainstream media to figure this out.

You keep hogging bandwidth talking about some old study that doesn't really prove diddly. If pot smokers are four times as likely to develop serious mental illness then you would think that there would be substantially higher rates of mental illness in states with substantilly higher per capita marijuana use. Is there? Of course not, in fact it's really th other way around.

I saw this study you were talking about before and found it highly suspect. It did not prove causation. Just out of curiosity I did some checking into statistics on marijuana use and serious mental illness. The U.S. Department of Health and Human Services' Substance Abuse and Mental Health Services Administration (SAMHSA) collects data on both mental health issues and drug issues. My thinking was that if marijuana really causes serious mental illness, there would be correspondingly higher rates of mental illness in states with higher rates of marijuana use. Doesn't that seem logical?

First I looked at the state with the highest past month marijuana use, New Hampshire. In that state 10.23% reported use of marijuana in the past month on the last survey and and according to SAMHSA 8.8% of New Hampshire's population suffer from serious mental illness compared to the national average of 8.76%. Then I looked at the state with the lowest marijuana use, Utah. There only 4.00% reported past month marijuana use but SAMHSA says 10.97% suffer from serious mental illness.

Now, that was interesting to me but there are too many variables that can come into play that call into question the results from just two examples. So, I dug a little deeper and looked at the ten states with the highest and ten states with the lowest marijuana use. The national average past month marijuana use was 6.18%. The top ten states averaged 8.93%. Serious mental illness in these states averaged 8.73%, compared to the national average of 8.76%. Serious mental illness in the ten states with the lowest marijuana use averaged 9.44%, even though past month marijuana use only averaged 4.73% in these states.

Why is it that the states with the highest marijuana use actually lower rates of serious mental illness than the states with the lowest marijuana use? I honestly don't know. I don't think you could conclude from that that marijuana use reduces mental illness, but it certainly does call into question research that shows that marijuana use drastically increases mental illness.

Here are the tables I used from SAMHSA's 2003 NSDUH. The link to the past month marijuana use by state is here: http://www.oas.samhsa.gov/2k3State/appB.htm#tabB.3

The link to the serious mental illness numbers by state is here: http://www.oas.samhsa.gov/2k3State/appB.htm#tabB.21