LONDON, May 1, 2007

Doctors: Marijuana Triggers Psychosis

Study Used Brain Scans For First Time To Show Link Between Pot And Paranoia

  • Robert Varela, a television cameraman, shoots a closeup of marijuana growing in a home in Diamond Bar, Calif., in this March 28. 2007 file photo. Photo

    Robert Varela, a television cameraman, shoots a closeup of marijuana growing in a home in Diamond Bar, Calif., in this March 28. 2007 file photo.  (AP Photo/Nick Ut)

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(AP)  New findings on marijuana's damaging effect on the brain show the drug triggers temporary psychotic symptoms in some people, including hallucinations and paranoid delusions, doctors say.

British doctors took brain scans of 15 healthy volunteers given small doses of two of the active ingredients of cannabis, as well as a placebo.

One compound, cannabidiol, or CBD, made people more relaxed. But even small doses of another component, tetrahydrocannabinol, or THC, produced temporary psychotic symptoms in people, including hallucinations and paranoid delusions, doctors said.

The results, to be presented at an international mental health conference in London on Tuesday and Wednesday, provides physical evidence of the drug's damaging influence on the human brain.

"We've long suspected that cannabis is linked to psychoses, but we have never before had scans to show how the mechanism works," said Dr. Philip McGuire, a professor of psychiatry at King's College, London.

In analyzing MRI scans of the study's subjects, McGuire and his colleagues found that THC interfered with activity in the inferior frontal cortex, a region of the brain associated with paranoia.

"THC is switching off that regulator," McGuire said, effectively unleashing the paranoia usually kept under control by the frontal cortex.

In another study being presented at the conference, a two-day gathering of mental health experts discussing the connections between cannabis and mental health, scientists found that marijuana worsens psychotic symptoms of schizophrenics.

Doctors at Yale University in the U.S. tested the impact of THC on 150 healthy volunteers and 13 people with stable schizophrenia. Nearly half of the healthy subjects experienced psychotic symptoms when given the drug.

While the doctors expected to see marijuana improve the conditions of their schizophrenic subjects — since their patients reported that the drug calmed them — they found that the reverse was true.

"I was surprised by the results," said Dr. Deepak Cyril D'Souza, an associate professor of psychiatry at Yale University's School of Medicine. "In practice, we found that cannabis is very bad for people with schizophrenia," he said.

While D'Souza had intended to study marijuana's impact on schizophrenics in more patients, the study was stopped prematurely because the impact was so pronounced that it would have been unethical to test it on more people with schizophrenia.

"One of the great puzzles is why people with schizophrenia keep taking the stuff when it makes the paranoia worse," said Dr. Robin Murray, a professor of psychiatry at King's College.

Experts theorized that schizophrenics may mistakenly judge the drug's pleasurable effects to outweigh any negatives.

Understanding how marijuana affects the brain may ultimately lead experts to a better understanding of mental health in general.

"We don't know the basis of paranoia or anxiety," said McGuire.

"It is possible that we could use cannabis in controlled studies to understand psychoses better," he said. McGuire theorized that could one day lead to specific drugs targeting the responsible regions of the brain.

© MMVII The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.

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Add a Comment See all 84 Comments
by gunownerdan May 1, 2007 6:41 AM PDT
Marijuana has been illegal and demonized for so long, no wonder people get paranoid after smoking it. It is pretty frightening to think that you can be arrested just for a seed or a stem.
COPS SAY LEGALIZE MARIJUANA!
http://www.leap.cc
Law Enforcement Against Prohibition
Reply to this comment
by griking May 1, 2007 6:44 AM PDT
So how much was spent to determine that weed can cause paranoia? Um, isn't this common knowledge already. What's next, a national alert warning us of munchies? they can do all the test they want. Pot will never be as dangerous as all of of the legal name brand drugs out there
Reply to this comment
by jjp735i May 1, 2007 6:54 AM PDT
We all know some people show the same findings of being paranoid from drinking too!
Reply to this comment
by geneonlbk May 1, 2007 7:33 AM PDT
Ever see any government statistics on driving fatalities and pot? And you know you would have if there were any. Let's see, hundreds of thousands killed and injured fron alchohol on the highway, and no government propaganda about driving and pot; of course we should leave the laws as they are, and spend millions housing three time pot users in prison, and spending ten times more on drunk driving patients in hospitals. That makes all the sense in the world!
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by mcvet May 1, 2007 7:53 AM PDT
It's amazing!! The report comes out showing, without a doubt, that the War on Drugs is a complete failure and these storys start to show up. Hummmm??? I wonder if a bunch of do nothing idiots are concerned with losing their cushie jobs?
Reply to this comment
by cbse3 May 1, 2007 8:04 AM PDT
The Alcohol Lobby is extreamly large, has a lotto
influence and doesn't like competition, in fact so much so as to over come stats like the drinking and drivers of the world, there were 33,804 US alcohol related deaths for 2004 and 2005 combined. So thats like 41 VT shootings per month.It looks to me like the bottle is mighter than the gun. Check out the MADD.org for confirmation if you need too
And these stats don't even begin to expose how many practicing alcoholics do their thing on a daily basis
Reply to this comment
by djconklin May 1, 2007 8:05 AM PDT
"The report comes out showing, without a doubt, that the War on Drugs is a complete failure and these storys start to show up."

That isn't what this report is about at all. You read what you wanted to see--it's one of the side-effects of the THC: hallucinations.

"COPS SAY LEGALIZE MARIJUANA!"

The police don't legalize anything; they simply enforce the laws that are on the books.
Reply to this comment
by oleander8 May 1, 2007 8:24 AM PDT
...it's still safer than booze.
Reply to this comment
by cbse3 May 1, 2007 8:55 AM PDT
wonder what the or if there is any cooralation of thc levels in herb as to the "proof" is in alcohol, something more significant than just saying "this is kick a*s" or "this is the the good sh*t man"
Reply to this comment
by omega39-2009 May 1, 2007 8:56 AM PDT
And Prozac has been linked to suicides, but that hasn't stopped the schools and big pharma from pouring them down our children's throats.
Reply to this comment
by harp1963 May 1, 2007 9:05 AM PDT
Living clean is the best way to approach life. 23 years ago though, when I was in college, I saw way more fights, car accidents, and belligerent behavior by others who drank alcohol. The pot smokers were generally goofy, funny, relaxed, and searching for ways to buy more pizza. I guess in a society that is geared for money, money, and more money that's not a good thing, unless your in the pizza business.
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by petitelys May 1, 2007 9:09 AM PDT
this study is bull. THC and cannabidiol don't exist separately in pot. the differences in the high you get from different quality pot is dependent on the ratio between the two (and how much you take). the higher the THC:cannabidiol ratio, the more 'psychotic/paranoid' side effects; the lower the ratio, the calmer you are. so schizophrenics who claim they are calmer after smoking mj very well could be...for sure they're not getting pure THC when they smoke. to state the marijuana as a whole will unequivocally worsen pyschotic disorders is bad science. what should be happening is research into what ratios of THC: cannabidiol give the most effective therapeutic range with the least side effects.
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by extremophil May 1, 2007 9:11 AM PDT
So marijuana causes psychosis. And parents cause children, floods cause drowning, dogs cause barking, fires cause burns (gee, this is fun), trees cause leaves, etc cause etc.......
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by mitch0927 May 1, 2007 9:16 AM PDT
To me, if they didn't have such a hard on about busting you for it, then I think the survey would have been different. Of course if someone is going into work stoned, they are going to be a bit paranoid. Those people should be fired immediately.
Reply to this comment
by mbcsmith May 1, 2007 9:17 AM PDT
What a bunch of bull. This study in no way duplicates the effects of...gotta go..killer monkies coming through window....
Reply to this comment
by cbse3 May 1, 2007 9:17 AM PDT
hey harp 1963 it looks like you've broken part of the code.
Out of all past aquaintaces and friends there are several alcoholaics and no reeferholics and most of the problems did and still do come fromm the juicers... I've been out of college for 35 years
Reply to this comment
by mitch0927 May 1, 2007 9:20 AM PDT
A child should blame cookies for causing this as well, because a kid caught with stealing cookies from the cookie jar has the same symptoms.
Reply to this comment
by laland69 May 1, 2007 9:20 AM PDT
This study is bull! The people who are coming up with these ridiculous studies are the ones who are hallucinating and are paranoid. In all of my years of smoking pot(the good stuff) and knowing all the people who smoke it regularly and who have good jobs i have never seen or heard them hallucinating. This makes me not believe any medical study that comes out on anything. This is a way to stop for the increasing support to legalize marijuana.
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by mitch0927 May 1, 2007 9:27 AM PDT
AMEN laland69
Reply to this comment
by cosmicfluke May 1, 2007 9:35 AM PDT
what a load!
they had to have a study that demonized pot after that last one that cleared it of causing cancer.
it's a real struggle to keep pot illegal as more and more people wake up to the fact that marijuana prohibition is economically motivated.

pot causes psychosis!!!

what ***, I've been smoking almost every day since 1977, and have been around tens of thousands of pot smokers under all conditions, and I've NEVER seen anything to confirm these ridiculous studies.
Reply to this comment
by triastra May 1, 2007 9:39 AM PDT
Interesting how the tone and title of an article about the same study is different in The Guardian.

http://www.guardian.co.uk/science/story/0,,2069736,00.html
Reply to this comment
by gunownerdan May 1, 2007 9:40 AM PDT
Why is marijuana still illegal?

- Legalization would endanger billions of dollars in prison and law enforcement spending, thousands of jobs would be at stake.

- It is useful in society to have some laws which virtually everybody breaks - that way undesirables can be arrested at will.

- Legal drugs would interfere with the existing pharmaceutical industry.

- Fully legal hemp would interfere with existing paper, rope, clothing and other industries.

- The war on drugs provides a convenient cover under which to project U.S. influence into many countries, particularly in South America and South Asia.

- The war on drugs is a critical revenue source for the prison industry, the CIA, and the DEA.

http://www.leap.cc
http://www.mpp.org
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by gramto7 May 1, 2007 9:43 AM PDT
this study is bull. THC and cannabidiol don't exist separately in pot. the differences in the high you get from different quality pot is dependent on the ratio between the two (and how much you take). the higher the THC:cannabidiol ratio, the more 'psychotic/paranoid' side effects; the lower the ratio, the calmer you are.
Posted by petitelys

I guess you aren't as brilliant as you wanted to appear. If the two did not exist separately, there could not be a ratio between them.
Reply to this comment
by gramto7 May 1, 2007 9:47 AM PDT
What a bunch of bull. This study in no way duplicates the effects of...gotta go..killer monkies coming through window....
Posted by mbcsmith

GOOD ONE!!
Reply to this comment
by dogsoul May 1, 2007 9:47 AM PDT
Oh come ON now folks - you're all going to tell me that pot does NOT make you paranoid? Of COURSE it does! - at least for a lot of folks... Look, I'm by no means an anti pot crusader.... I used to smoke a LOT of pot, daily - and I can tell you first hand that although I DO agree it's less harmful than alchohol - it most certainly DID make me paranoid & unmotivated to venture out. Ever get high & have a minor conflict arise that wouldn't normally "freak you out"? Eventually, it got to the point where I'd get high, then spend a while fighting it because of the paranoia effect. There was one time when I got high & then suddenly had to drive my dad to the airport... sheeez, talk about paranoid! That's why I gave it up - just wasn't enjoyable anymore... maybe if you've got a stress free life, like most college students or something that's one thing... but for many, it only ends up adding to the stress.
Reply to this comment
by petitelys May 1, 2007 9:47 AM PDT
triastra, thanks for the link. add it to the growing body of evidence for people that don't believe that our media works for the government. unbiased, my a$$.
Reply to this comment
by rsoxfan1123 May 1, 2007 9:48 AM PDT
marijuana enters you into a seperate state of mind. Most of the people posting on here scoffing at this study probably have a significant tolerance for it and have learned to handle it. It may well be another story for a schizophrenic that hears voices in his head anyway when sober to get absolutely blown on really strong weed.
Reply to this comment
by rsoxfan1123 May 1, 2007 9:48 AM PDT
marijuana enters you into a seperate state of mind. Most of the people posting on here scoffing at this study probably have a significant tolerance for it and have learned to handle it. It may well be another story for a schizophrenic that hears voices in his head anyway when sober to get absolutely blown on really strong weed.
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by drummer94 May 1, 2007 9:49 AM PDT
Anybody remember, from a bunch of years back, that the government was growing the stuff with the help of the tobacco cos because it was close to being decriminalized and they saw a way to tax it? There's a saying: You don't get any higher, you just get less dope.
Reply to this comment
by petitelys May 1, 2007 9:58 AM PDT
I guess you aren't as brilliant as you wanted to appear. If the two did not exist separately, there could not be a ratio between them.
Posted by gramto11 at 09:43 AM : May 01, 2007

not trying to appear brilliant. just stating an opinion. but you're right. i should have said you don't find marijuana with just one or the other that they always exist in combination. and really it's the article, not the study that's bull. it makes me so mad when media/government/whoever mislead the public by distorting scientific findings to achieve a certain goal.
Reply to this comment
by ginner45 May 1, 2007 10:09 AM PDT
come on psychosis, don't you think that a joint is making people psychotic???Don't you think that a drink of alchol, a run in with someone who makes you mad, your wife and kids do just something wrong and that dosen't trigger the psycosis???????I have never in my life saw any person smoke a joint and get mad, abuse their wife and kids? Just because the govenment has not figured out a way to tax it, here we go with psychosis. Also I believe that paranoia is also triggered by anger, the way you got to here, and I cannot believe it was the joint. Try it and chill out.............
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by zoltaric May 1, 2007 10:10 AM PDT
How do I sign up for this test?
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by luvny-2009 May 1, 2007 10:24 AM PDT
Hey works for Willie! I saw yesterday Good Ol'Willie Nelson turned 74. Was it last year they raided his bus and found mushrooms and Pot ...LOL how funny is that. Good thing they got'em...I mean you know Willie is a dangerous outlaw LOL
Reply to this comment
by janke8 May 1, 2007 10:31 AM PDT
Tell ya the truth...I don't believe anything anyone says about much of anything...Studies are just that STUDIES one day eggs are bad, next day they are good, coffee is good, coffee is bad, red wine is bad, red wine is good....if they didn't write about this it would be something else..Afterall..even paper pushers need to make some kind of living...and think of all the millions our government spends for grants for all this stuff!!! WOW!! a never ending circle!!
Reply to this comment
by mperkel May 1, 2007 10:37 AM PDT
It's another anti-pot propaganda piece. If pot were so bad there would be more pot related crime. I think the fact that 12 states have some form of legal marijuana shows that it's the feds that are the ones who are paranoid. They are so paranoid that they have to make up fake studies like this one.

The church of Reality is close to being allowed to use pot legally. That's going to be interesting if we get it.
Reply to this comment
by rav_2810 May 1, 2007 10:40 AM PDT
Blows me away that they are actually TESTING this stuff still yet. Ask 80% of all high school/college students what marijuana does to you, i'm pretty sure they will tell you exactly what these studies have shown, and for FREE!! Also, not that we have more dire things to worry about in the world today, terror, global warming, the bush presidency.. you know.. the horrible things that effect everyone in the world these days. Lets just play dumb and look over everything else and concentrate on the really horrible things.. like MARIJUANA!!
Reply to this comment
by briannorwood May 1, 2007 10:42 AM PDT
...triggers temporary psychotic symptoms in some people, including hallucinations and paranoid delusions...

DUH, THATS THE POINT, ISN'T IT!
Reply to this comment
by one_american May 1, 2007 11:06 AM PDT
So THIS explains "Bush Derangement Syndrome" and the 9/11 Conspiracy Theorists! Fascinating!
Reply to this comment
by reena6 May 1, 2007 11:13 AM PDT
DON'T PEOPLE HAVE ANYTHING BETTER TO STRESS ABOUT?
Reply to this comment
by condumism May 1, 2007 11:14 AM PDT
2001 Alcohol related deaths in the USA: 75,766.
2001 Marijuana related deaths in USA: 3.

Once again, corporate america reporting the non-news, the incomplete news and distroted facts to an imbecilic America.
Reply to this comment
by incog-nito May 1, 2007 11:17 AM PDT
Wow, a total of 15 people for the test, including those taking the placebo. And they called this conclusive scientific evidence? What a bunch of crock.
Reply to this comment
by clevercandi May 1, 2007 11:19 AM PDT
I've smoked pot for 30+ years on a daily basis and I have NEVER hallucinated!

Let's decriminalize marijuana once and for all! Vote LIBERTARIAN!!! www.lp.org for more info.
Reply to this comment
by waltonrp May 1, 2007 11:25 AM PDT
Didn't we used to call that tripping and being paranoid? What a bunch of croc
Reply to this comment
by nottellin1 May 1, 2007 11:27 AM PDT
mperkel

Ewww...good one. The govenment has been smoking too much pot and has made them paranoid. What a great concept!
Reply to this comment
by briannorwood May 1, 2007 11:30 AM PDT
CleverCandy wrote...

"...I've smoked pot for 30+ years on a daily basis and I have NEVER hallucinated!"

Me either...at least not while smoking pot!
Reply to this comment
by lochlan-2009 May 1, 2007 11:35 AM PDT
CNN just did an attack article on marijuana that looked as if it was written by the DEA. Looks like they're gearing up distract us with marijuana and legalize it or not stories for a few months. Ahhh.... maybe I'm just being paranoid.
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by wisemom May 1, 2007 11:54 AM PDT
I have a 28 year old schizophrenic daughter. She has been hospitalized 4 times in the past six years after smoking pot. It may not affect all schizophrenics this way but for my daughter, it was true. She does fine on medication - go off for a weekend and smoke pot - bam! She has severe psychotic episodes and I end up having to take her to the hospital. It has caused her severe damage in her treatment.
Reply to this comment
by condumism May 1, 2007 12:08 PM PDT
Need facts about pot? You won't find any by searching Google or any other search engine in the USA, only smear controlled by the Neocon Fascists that permeate the Bush administration of smear tactics. Europe publishes all the facts about pot, both good and bad. Their take on the bad consists of warning potential users that pot may increase their appetite, thus causing unwanted weight gain.
Reply to this comment
by jjreding-2009 May 1, 2007 12:24 PM PDT
I have literally know HUNDREDS of pot smokers over the years and not one of them has ever shown signs of paranoia (except that which you get about getting caught with something less harmful than alcohol). My friend with epilepsy swears by it because it helps keep his incidents down, and how many people have we heard about that get relief from glaucoma and chemotherapy side-effects. If this country would just legalise it like it is in Amsterdam (a country by the way with one of the lowest crime rates in the world) they could tax the hell out of it and the deficit would be erased rapidly - despite Bush's attempts at keeping it high with his illegal war.
Reply to this comment
by rushman71 May 1, 2007 12:33 PM PDT
"Leads to temporary psychotic symptoms"--hummm, let me see, makes you forget what you were talking about a few minutes ago, causes a need to settle that sudden desire for food, makes you laugh harder at stupid subjects, and last but not least, the overdose effect--falling asleep on the couch. Those truly do sound psychotic, don't they!!!!!
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