Early cannabis users three times more likely to have psychotic symptoms

Feb 27, 2010

Young adults who started using cannabis at an early age and used it for several years are at increased risk of being diagnosed with a form of psychosis, of hallucinating or having delusions, a study published Monday found.

Researchers at UQ's Queensland Brain Institute and School of Population Health have found young adults who use cannabis from an early age are three times more likely to suffer from psychotic symptoms.

A study of more than 3,800 21-year-olds has revealed those who use cannabis for six or more years have a greater risk of developing psychotic disorders or the isolated symptoms of psychosis, such as hallucinations and delusions.

The study is based on a group of children born at Brisbane's Mater Hospital during the early 1980s. They have been followed-up for almost 30 years.

“This is the most convincing evidence yet that the earlier you use cannabis, the more likely you are to have symptoms of a psychotic illness,” lead investigator Professor John McGrath said.

The research, published in the latest edition of Archives of General Psychiatry, also included the results of 228 sets of siblings.

“We were able to look at the association between early cannabis use and later psychotic symptoms in siblings. We know they have the same mother, they most likely have the same father and, because they're close in age, they share common experiences, which allows us to get a sharper focus on the specific links between cannabis and psychosis - there is less background noise.

“Looking at siblings is a type of natural experiment - we found the same links within the siblings as we did in the entire sample. The younger you are when you started to use cannabis - the greater the risk of having psychotic symptoms at age 21. This finding makes the results even stronger,” Professor McGrath said.

“The message for teenagers is: if they choose to use cannabis they have to understand there's a risk involved. Everyone takes risks every day - think of the sports we play or the way we drive - and people need to know that we now believe that early cannabis use is a risk for later psychotic illness.”

Schizophrenia is a serious disorder that affects about 1 in a 100 Australians, and usually first presents in young adults. This is also the time when the brain seems most vulnerable to cannabis.

Explore further: Understanding psychosis and schizophrenia

Provided by University of Queensland

2.1 /5 (42 votes)

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rgw
3.5 / 5 (11) Feb 27, 2010
Anyone who thinks cannabis causes psychosis is going on my list of those to be put against the wall when the revolution comes. Mnnhahahahaha!!!
Sean_W
3.7 / 5 (6) Feb 27, 2010
I suppose that if I were having hallucinations and such I'd smoke a lot of dope too. Keep the voices mellow. Instead of telling you that your neighbors want you dead they will tell you to buy more snacks.
aaaaaaaaa
3.9 / 5 (18) Feb 27, 2010
40% of Americans think Alien life forms are living in their community.
People hear voices from their Gods and some people claim to have seen Ghosts.

Why don't they test some of these nutters for psychosis.

Do the Dutch and Spanish where Cannabis is legal have more psychotics ?
The answer is No.

Come the Revolution.

Bob_B
3.9 / 5 (14) Feb 27, 2010
Those folks that believe they talk to a god or that a god will protect them or help them win a football game are in the majority so they can't "step back" and see how stupid and dependent they are on a false assumption. Most of these people go to their graves with these false beliefs and those that try to help them are told to go away.
Alphakronik
4 / 5 (8) Feb 27, 2010
Cannabis/schizophrenia link questioned
July 26, 2007

The Swiss government is questioning the results of a study showing a link between marijuana use and schizophrenia.

The Zurich University study showed a higher incidence of schizophrenia in the 1990s in the age groups most likely to use cannabis, Swissinfo said Wednesday.

"We know from other experimental studies that cannabis can cause psychosis, but we have now established a clear link to schizophrenia for the first time," study co-author Wulf Rossler said.

Swissinfo said the Federal Health Office is questioning the report, saying the patients' drug histories and other medical details remained unknown.

"It does not uncover the medical history of the patients, for instance the consumption of psychotic substances or other factors that could lead to psychotic illnesses," the health office in a statement.

Copyright 2007 by United Press International
Shizzam1001
Feb 27, 2010
This comment has been removed by a moderator.
bmcghie
3.9 / 5 (7) Feb 27, 2010
^ and ^^ THANK YOU. There's not nearly enough information on these patients. Given my experience with the bud, and all the situations wherein I've observed people high on marijuana... I'm disinclined to take this study at face value. Show me their patient histories, and developmental conditions/social upbringing, then I'll be prepared to listen to your argument.
Mercury_01
4.2 / 5 (5) Feb 27, 2010
I had a roommate once that went missing during his first big schizophrenic episode. He had been self- medicating with herb and alcohol and had been mal- adjusted through his entire life, well before his schizophrenia had fully developed. His parents even sent him out of state for a youth substance program, which just made him worse off in the end. I would have to say that in his case, the troubles didn't start with the herb, he he was already at risk for all kinds of abuse. I would bet my paycheck that if this study was conducted in an identical way with alcohol in place of cannabis, they'd find the same results
Bloodoflamb
3 / 5 (2) Feb 27, 2010
Did they study the histories of mental illness prior to their beginning to smoke marijuana, including personal and familial histories? Probably not, I'd wager!
RobertKLR
not rated yet Feb 27, 2010
Uh, Ya' see, uh, dude I was gonna... Well crap, I forgot what I was gonna say.
bmcghie
Feb 27, 2010
This comment has been removed by a moderator.
nojuego
1 / 5 (2) Feb 27, 2010
So if you start going crazy, then start smoking marijuana to not be so crazy, and you get crazier, marijuana caused you to go crazy? Makes perfect sense.
Che2000
3.7 / 5 (3) Feb 27, 2010
I will take weed over alcohol forever and ever. Weed rules.
jimbo92107
3.7 / 5 (6) Feb 27, 2010
Subjects started smoking pot at 15 and were assessed at 20?

Good lord. Who calls that "long-term use?" I know people that have been smoking pot on a regular basis (every day) for over 30 years. Small sample size, but none of them seem crazy to me.

I'd rather smoke pot than drink right wing Kool Aid.
posthypnodrumiouslydumb
3 / 5 (2) Feb 27, 2010
wow, thats like the definition of bad science. nice 1 guys. Note in the 50's & 60's the US gov performed "science" to prove that marijuana made you homicidal.
rincewind
Feb 28, 2010
This comment has been removed by a moderator.
sender
1 / 5 (1) Feb 28, 2010
I'd bet caffeine, alcohol and tobacco would have higher numbers.
Also:
http://jop.sagepu.../8/4/204

Dopamine helping cure schizoaffective individuals?
GaryB
3.4 / 5 (8) Feb 28, 2010
There are billions of people who think that if you believe in an invisible being who controls everything ... and, get this, you also have to believe in that this being also has invisible angles, that this thing wrote some books transcribed by some obscure guy living in a desert that says that everyone will be judged but, ha! it's all predestined. Well, then if you're predestined to believe, you're !!saved!! Another couple billion think if you believe in a now invisible guy who died 2K years ago, you're also saved. All this, in spite of the fact that the only things humans did that has ever done any good is invent rationality and science.

If that isn't psychosis and dysfunctional delusion, nothing is. I'm not sure, but I think the world would probably improve if more of the delusional billions would smoke more weed. Maybe they'd be happier and wouldn't feel so much need to inflict others with their delusions.
jgelt
Feb 28, 2010
This comment has been removed by a moderator.
philosothink
3.9 / 5 (8) Feb 28, 2010
The title of the article is very misleading, I suspect to assure party line compliance and generate hits. Unfortunately, such a small percentage of our population has functional reasoning capacity, they fail to understand the importance of this paragraph, or they are too emotional by the time they've read this far in the article to grasp what it says.

"People who were vulnerable to psychosis, in other words had isolated psychotic symptoms, "were more likely to commence cannabis use, which could then subsequently contribute to an increased risk of conversion to a non-affective psychotic disorder," the research said."

The real question at hand, is HOW the two are linked. I suspect it is the introspective nature of the Herb. If you take a person prone to schizophrenia, and give them a medicine that causes one to have deep inner contemplation, it's a bad combination which quickens the slide into failed mental heatlh.
KBK
1.3 / 5 (8) Feb 28, 2010
Some of you ,as armchair researchers, or 'astute observationalists' will understand this, some will not. Researchers in dimensional phenomena, and multiverse theories,and that included Einstein, BTW - will take note. People who are capable of psychic phenomena have the ability to bypass the egoic block (the ego itself)that is created by the rise of the reflection of the 'infinite'.

One problem is that the body may die, but the multi-dimensional within, does not. So the body-superluminal/dimensional mind quandary/interface is set up. Memory is a strange thing. Read Dr. Micheal Newton's regressive hypnosis works to clarify some of this. Smoking herb, blocks the memory that is trying to come through (you are spiritual being having a human experience, or a multi-dimensional being having a 3-d experience), as does alcohol.

Schizophrenia is a 3-d medical phenomena, to a certain degree. Mis-diagnosis due to incomplete (short ranged-limited mind) concepts and apps, is the real issue here.
Hephaestoskin
4 / 5 (5) Feb 28, 2010
I am bipolar and have suffered from depression and mania for as long as I can remember. While I have finally found a prescription medication that works, cannabis was the cure for my mania for years. So HA!

On a side note, cannabis contains multiple chemicals, most notably THC and CBD. The ratios between the two create a different high. High CBD strains (or sativa variety) were the only effective strain for me. High THC strains (often used for pain, indica variety) exacerbated my disillusions and depression/mania. CBD vs THC within the plant is also dependent upon UV-B exposure. This makes the study of marijuana in terms of phycological effects difficult without standardized strains.

Oh and I know this due to constant research, experimentation and the fact I have a green thumb.
JJC
2 / 5 (3) Feb 28, 2010
"233 had at least one hallucination"

What does this mean? Assuming it is a completely non-debilitating, one-time phenomenon, then I don't see what it has to do with anything. Many of the non-cannabis users probably had hallucinations but didn't know how to identify/label/report them because they had no previous experience.

Taking away that, all the article says is that (adding the numbers) 48.2% of their participants used cannabis, or 1832 people. That seems high.

Of those, only 65, or 3.5% showed signs of "non-affective psychosis". This does not seem high, and of course correlation is not causation.

What is the rate in the general population? What is the rate among the 51.8% of people who didn't use cannabis in their study?

All in all this is pretty weak evidence of anything.
shadfurman
2.6 / 5 (5) Feb 28, 2010
C'mon guys, cannabis changes your brain chem. Of course thats going to increase the likelihood of having hallucinations. For those denying it, I PERSONALLY have had MANY hallucinations on weed and I don't on shrooms (I just get imaginary stars at the edges of my vision and forget what I'm doing a lot) In fact the hallucinations started causing panic attacks and now if I smoke I go into shock, believe me, it's a pain, now I can't even smoke anymore.

And yes, from what I've read caffeine causes more hallucinations than cannabis or alcohol. The way I understand it is on caffeine your brain spends less time confirming or "voting" between neurons. On high doses of caffeine (which many people do since the advent of "energy" drinks) you brain will actually miss identify all kinds of stimuli. Once what you see and hear etc, gets far enough out of sync and as your brain struggles to adjust and correlate your senses you can enter a full fledged hallucination.
jth
5 / 5 (2) Feb 28, 2010
Where's the source, the actual study, please?

It's not in the linked journal's current issue or any of its past three months either. It's not mentioned on the lead researcher's home page. None of the dozens of articles I checked have links.
Alphakronik
4.5 / 5 (2) Feb 28, 2010
I am bipolar and have suffered from depression and mania for as long as I can remember. While I have finally found a prescription medication that works, cannabis was the cure for my mania for years. So HA!

On a side note, cannabis contains multiple chemicals, most notably THC and CBD. The ratios between the two create a different high. High CBD strains (or sativa variety) were the only effective strain for me. High THC strains (often used for pain, indica variety) exacerbated my disillusions and depression/mania. CBD vs THC within the plant is also dependent upon UV-B exposure. This makes the study of marijuana in terms of phycological effects difficult without standardized strains.

Oh and I know this due to constant research, experimentation and the fact I have a green thumb.


You forgot CBNs. :D
tkjtkj
2.3 / 5 (3) Feb 28, 2010
Once again, the 'DEA/Gov' mentality seeks to use deceit rather than facts. This seems to be a totally uncontrolled, contrived 'study'. Did they not consider that people who have had hallucinations under mind-altering substances, and done so within supportive groups, be more inclined to ADMIT them!?????? This is an obvious consequence of this poor study design!!! Not only obvious, but critically important!

2cen
1 / 5 (4) Feb 28, 2010
I suspect that so called "hallucinations" may be more real than we think; that "reality" is vibrational--and that thru meditation, stopping the internal dialogue, herbs, trauma, etc., we can change "channels." Of course, if we've "lost reason" what we witness is translated into "irrationality." Some of the stuff out there is beyond rationality, but a lot depends on the person doing the hallucinating. Balance. impeccability and common sense lead to equanimity. It ain't for the faint hearted
ormondotvos
3 / 5 (2) Feb 28, 2010
Same old bullshit. No links, no refs. Bad science. Bad Physorg!
maxcypher
3 / 5 (2) Feb 28, 2010
Put a serious dent in the business of greedy and corrupt law-enforcement as well as in organized crime: legalize all drugs! Let those who want to end it all via abuse find their own destiny and let those who who want help in stopping abuse find readily available treatment. So much suffering due to greed and ignorance. Our laws treat corporate 'persons' much, much better than real persons. Treat corporations for their sociopathic addiction to the 'bottom line'. Well OK, I got off track there, but our current society is so frustrating to behold and studies like this just further the problem!
KB6
5 / 5 (3) Feb 28, 2010
Too bad pharmaceutical firms can't figure out a way to make money off "therapeutic marijuana." If they could, all of these supposed hazards of marijuana use would be excused as "rare but serious side-effects."
I tried finding some *honest* studies of deaths due to prescription drugs when taken as directed (not due to abuse). But everybody on every side of that issue has an agenda: the drug companies, cops, the feds, injury lawyers, "holistic healers", herbal supplement sellers, the people who use and abuse prescription drugs, etc.
Trying to find truly non-biased, comprehensive, scientifically valid studies in that vast ocean of BS is damn near impossible.
Paradox
3.7 / 5 (3) Feb 28, 2010
I saw a commercial the other day for Asthma medicine.
One of the possible side effects of this medicine was ASTHMA RELATED DEATH.
Another medication I saw could give you "Anal leakage".
Come on, with this stuff being approved there shouldn't be any problem with cannabis.
maxcypher
3 / 5 (2) Mar 01, 2010
All these sort of issues make me want to puke! Legalize it! Do that and so many problems in our so-called society would be helped! We spend so much of our budget on a ridiculous agenda! Doesn't it make you want to tickle somebody??
Rajd
2.3 / 5 (4) Mar 01, 2010
Try it out , you'll feel like a superstar
after all it's given from nature and so.... next what we must stop eating cabbage or what ??/ come on dude look at the history of users they all big guys out there and they focused..
fourthrocker
1 / 5 (1) Mar 01, 2010
I have smoked and taken everything including good acid in the 70's and I have yet to have a single hallucination. If pot causes psychosis there are about 100 million psycho's in the good old US.
SEarlMartin
3 / 5 (2) Mar 05, 2010
I have seen stong evidence that Cocaine and Meth can cause hallucinations and psychosis. Were these subjects using anything besides Pot? I also have used Marijuana to help cope with bi polar disorder. It worked just fine after I found the correct strain. I have known people in my many years on this planet who did develop the afore mentioned symptoms. They all used speed and Cocaine. I never liked either one and have smoked most of my life and WE are just fine thank you. LOL!
Further many of the foremost scientists thru out history believed in God or a devine creator. Not all scientists are athiests. Peace
Claudius
2.3 / 5 (3) Mar 06, 2010
If cannabis were legalized, think of all the people who would be put out of work. The whole burgeoning prison industry would collapse, the DEA would have to find new work. It would collapse the entire economy. So it is necessary to demonize cannabis, and the powers that be are doing their best to do this, as these studies show.
Riff
not rated yet Mar 07, 2010
A couple years ago positive news came out about the legalization of pot. I cheered. 2 days later a report such as this one came out. A few months later, same thing. A few months later, same thing. Has Anybody else noticed that everytime pot gets closer to being legalized, within a couple days these 'studys' come out?
goldengod
not rated yet Mar 07, 2010
Psychosis caused by ganja is real. Whether or not it is a major issue in the general functioning of society is a seperate question. Smoking Weed has a lot of positive effects for many people. For those who don't get positive affects it is very sad to see them decline with age.

I still think the positive affects from ganja usage far outview the negative affects. If administered with care and not just as the thing to do to be seen as cool and tough then we all benefit from a calmer more gentle society.

These days it's hard to find anything that is not chronic or filled with chemicals and pesticides/fungicides. Smoking that everyday is probably a bigger cause of mental health issues than thc.

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