The Terrible Truth About Cannabis:...20-year Study...demolishes Claims That Smoking Pot Is Harmless

[Harry Dresden]

problem is it slows reaction time and causes more accidents.

i bet someone high can handle driving better than some one who is fucking drunk....

 

[Harry Dresden]

Cannabis is too much ingrained in the "legal" system as a cash cow to be easily legislated into legal use globally. LEO, lawyers, bondsmen, court staff, judges, prison staff, supporting contractors...all benefit from the prosecution of cannabis infractions, once defined in some states to mean the possession of one seed could lead to a felony conviction.

It's always going to be a money game. The lawyers and the "legal" system will always get richer!

and those same people you mentioned will still continue to smoke it themselves.....

 

[asaratis]

Cannabis is too much ingrained in the "legal" system as a cash cow to be easily legislated into legal use globally. LEO, lawyers, bondsmen, court staff, judges, prison staff, supporting contractors...all benefit from the prosecution of cannabis infractions, once defined in some states to mean the possession of one seed could lead to a felony conviction.

It's always going to be a money game. The lawyers and the "legal" system will always get richer!

and those same people you mentioned will still continue to smoke it themselves.....

Hey! Cops have the best weed in town! I know a lawyer back home that keeps a pot plant in his office. It's all a money game!

 

[C_Clayton_Jones]

Let's ban alcohol. What do you think?

Start a thread about alcohol. Doesn't change anything about pot.

No one said it does.

But it does illustrate how your position is inconsistent.

 

[MikeK]

Federal Report Marijuana Causes Mental Illness

If there were any substance to this latest federal anti-pot "report" there would be so many mentally ill Americans at large the Nation could not function.

The only "mentally ill" characteristic associated with marijuana is its prohibition: The war against pot has been vigorously waged since Nixon declared it. At least a trillion dollars has been spent on arresting and prosecuting Americans for selling and possessing it, effectively ruining their lives. Yet there is no credible, scientifically established evidence that any of the Reefer Madness claims made about it are true. In spite of this irrefutable proof that marijuana is not only relatively harmless but is beneficial in many ways, the same pointlessly redundant "war" continues to be waged against this natural plant. And what is doing the same thing over and over again and expecting a different result known as. . .?

So much for the federal claim.

 

[MikeK]

problem is it slows reaction time and causes more accidents.

i bet someone high can handle driving better than some one who is fucking drunk....

Any experienced highway cop will attest to that. Drunk drivers are erratic and move too fast. Stoned drivers all stay in the right lane, drive very slow, and rarely have accidents.

 

[MikeK]

I think that's part of it, but the availability of it now compared to years ago tells me it's being used more than before. You can see it growing out in the open in people's gardens. There's more pot, so more of it's being smoked.

And the shit stinks, and I should have the right to walk down the street and not have someone's smoke invade my nostrils. You want to use it, then keep it to yourself !

That's tobacco smoke you're smelling.

Marijuana smoke smells rather pleasant, like burning leaves in autumn -- and it makes you feel nice and relaxed. Even cats like it and will rush to inhale it.

 

[MikeK]

And yes maybe I do come across as angry, that might be because i haven't smoked in 4 months. Wife is pregnant and if she can't smoke then I can't either.

No worries....I'm 67 and saw the beginning of it with white kids. I tried it and sometimes I liked it and sometimes I didn't. The shit we were smoking was nowhere near the potency of what's around today. When I was sent to Vietnam I saw guys smoking the local weed and Thai sticks....that doesn't work out in indian country....we considered it unprofessional and dangerous out on patrol. A lot of draftees got their asses killed due to slow reflexes, bad judgement, and paranoia due to the weed. I didn't drink there either....nothing that would dull my reaction time. I got home alive and that was due in part to that. On the bird home I drank a quart of whisky between the RVN and Okinawa.

The first time I ever got high on marijuana was on Okinawa in 1957. What I didn't realize at the time was that rice-paddy weed was the most potent I would ever experience.

We bought it from the laundry mama-sans who brought a soup can packed tightly with cleaned bud which was almost purple in color and so resinous it ran down the paper and stuck to the fingers. The price was ten cartons of Pall Mall cigarettes, which cost a dollar a carton at the PX. Today that can wojuld cost six to eight hundred dollars.

Four or five good hits and your feet stuck to the floor. If you were lying down you couldn't sit up. And if you were sitting you couldn't stand. All you could do was think and giggle. But it made life on the "Rock" tolerable.

 

[MikeK]

In the authoritarian mind, the best thing about pot being illegal is that the drug dog can always be commanded to pretend it detects pot, thus giving the government a reason to search. And the nice officer can always pretend that the fragments of the lawn you tracked in on your shoes were really marijuana fragments, which gives him justification to confiscate and keep your car. Plus, if they're really against you, they can simply drop that little baggie into your car. It's a statist's dream, giving overwhelming power to the government.

Well said.

 

[MikeK]

Some have never progressed beyond the propaganda film, "Reefer Madness".
Thousands of studies have been done ... most conclude marijuana is not harmful.

Many of these studies saying pot is bad for you have been disproved by other studies. You have to look at these studies and see who would benefit from them.
It is like the controversy over whether milk is good for you after the nursing period. Some scientists say no, some yes. If you look at the ones who say yes, they are usually on the payroll of dairy associations.

There probably has never been a more persistent, imaginative, skillfully propagated system of professionally orchestrated deception in the history of propaganda than that of the anti-marijuana campaign conducted by the U.S. Government and certain corporate interests. And that includes the propaganda disseminated during WW-II.

Josef Goebbels, Hitler's Minister of Propaganda said, "Any lie, no matter how great, will be believed by the masses if it is repeated often enough!" And the anti-marijuana campaign is irrefutable proof of that.

 

[QuickHitCurepon]

Israeli researchers have been studying cannabis for over 50 years. Unlike most pharmaceuticals, it's benefits FAR exceed its' risks. You can die from drinking too much water (water intoxication et al.) even the OP article conceeds you can't overdose from cannabis.

What risk or fate could be worse than psychosis or schizophrenia?

and how often does that happen?

Very often if it doubles the risk.

Federal Report Marijuana Causes Mental Illness

May 3, 2005 -- Children who use marijuana before age 12 are twice as likely to later develop serious mental illness as those who don't try the drug until they're 18, according to a federal report released Tuesday.

Bush administration officials pointed to the study as growing evidence that smoking marijuana may cause mental illnesses -- including depression, schizophrenia, and suicide attempts -- in some people.

• It doubles risk of developing psychotic disorders, including schizophrenia

The terrible truth about cannabis Expert s devastating 20-year study finally demolishes claims that smoking pot is harmless Daily Mail Online

NAMI Marijuana and Mental Illness

Certainly not all people who smoke marijuana will develop schizophrenia, but people who are at risk of developing this illness—including individuals with close family relatives that have severe mental illness—will be more likely to experience psychosis if they are using marijuana.

Regular marijuana use bad for teens brains study finds -- ScienceDaily

Frequent marijuana use can have a significant negative effect on the brains of teenagers and young adults, including cognitive decline, poor attention and memory, and decreased IQ, according to psychologists discussing public health implications of marijuana legalization at the American Psychological Association's 122nd Annual Convention. ...

Some research has shown that frequent use of high potency THC can increase risk of acute and future problems with depression, anxiety and psychosis...

Smoking marijuana has been linked with an increased risk of mental illness, and now researchers say that when pot smokers do become mentally ill, the disease starts earlier than it would if they didn't smoke pot.

This means that serious psychiatric diseases that might not have shown up until kids were in their teens or twenties - or might never had developed at all are starting in children as young as 12 who smoke marijuana. ...

Smoking Pot May Hasten Onset of Mental Illness Fox News

you do realize for just about every anti-pot "study"......there is a pro-pot "study" that counters it.

And yet you have posted links to no such studies. I have seen only one study posted that counters the widespread belief that marijuana causes schizophrenia. Sorry, but one study does not counter widespread knowledge.

Marijuana and Schizophrenia 8211 A Clear and Unmistakable Link 8230 ignored in America Warm Southern Breeze

Marijuana and Schizophrenia – A Clear and Unmistakable Link… ignored in America
April 20, 2010

There is a significant and growing scientific body of medical evidence that marijuana use contributes significantly to schizophrenia – a particularly debilitating mental health condition that strikes during the most productive years of one’s life.

Medical marijuana anyone?

Maybe you’d prefer your mental health, instead.

It’s a shame that mental health professionals and other researchers in the United States almost wholly ignore the vast, longitudinal (long-term) and increasing body of evidence that conclusively demonstrates that marijuana DIRECTLY contributes to schizophrenia. ...

• Cannabis and schizophrenia. A longitudinal study. – Lancet, 1987 – 15 yr, 45,570 subject study of Swedish soldiers demonstrated significant risk for schizophrenia when compared to non-users and controlled for other factors, increased the risk of suicide 400%

• A 35-year longitudinal study published in the British Journal of Psychiatry, found that schizophrenia rates doubled among marijuana users in South London. 2003 Jan 1 ; 182():45-9

• Professor Jim van Os, Lead Researcher University of Maastricht, Netherlands followed 2437 people aged 14 – 24 four years. Findings published in the British Medical Journal revealed that controlled for other events, 51% of cannabis users experienced schizophrenic symptoms versus 26% of non-users.

• Robin Murray, Institute of Psychiatry, London, UK, found that cannabis smoking accounts for about 8% of serious cases of psychosis.

• Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident case. Br J Psychiatry. 2005 Dec;187:510-5 [Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders follow-up study of 535 incident cases ]

The environment and schizophrenia: the role of cannabis use. Schizophr Bull. 2005 Jul;31(3):608-12. Epub 2005 Jun 23. [ The environment and schizophrenia the role o... Schizophr Bull. 2005 - PubMed - NCBI ]

Predictors of schizophrenia–a review.
 Br Med Bull. 2005 Jun 9;73:1-15. Print 2005.

Cannabis as a risk factor for psychosis: systematic review.
 J Psychopharmacol. 2005 Mar;19(2):187-94.

[Acute and chronic cognitive disorders caused by cannabis use] Rev Prat. 2005 Jan 15;55(1):23-6; discussion 27-9. French.

NAMI Blog Marijuana and the Risk of Schizophrenia

Marijuana and the risk of schizophrenia
Mar 31, 2011
By Ken Duckworth, M.D., NAMI Medical Director

The ongoing link between use of marijuana in teens and the increased risk of developing schizophrenia has been further developed in a recent Dutch study published in the British Medical Journal (BMJ) and has re-ignited that area of interest...

The BMJ study looked at young adults who were at risk for psychosis and found that the rate of conversion to the illness was 51 percent with marijuana users-compared with 26 percent of nonusers. This study builds upon a growing body of literature that is making this causative link. This build upon other studies-one of the most interesting to me was a study that made a case for delaying all experimentation---the study found that users before age 15 were 4.5 times more likely to develop schizophrenia than nonsmokers, and those who delayed until age 18 had a risk of 1.6. This strongly suggests that, in addition to abstinence, delaying experimentation results in reduced risk. ...

Does using marijuana increase the risk for developing schizophrenia Portal de Pesquisa da BVS

As more US states and other countries consider legalizing marijuana, clinicians need to know the possible effects of this drug. Research has shown a connection between marijuana use and an increased risk for schizophrenia in young people who are vulnerable to developing psychosis. An international panel of experts addresses topics such as risk factors for schizophrenia, the potency and effects of cannabis use on adolescents, the effects of concurrent drug use with cannabis on schizophrenia risk, and current attitudes toward marijuana.

Predictors of schizophrenia a review

In a review by Arseneault et al.71 of five prospective population-based studies, cannabis use was estimated to confer an overall 2-fold increase in the relative risk for later schizophrenia on an individual level. In particular, those cannabis smokers who have genetic vulnerability or some baseline psychiatric symptoms have increased risk of schizophrenia.72 At the population level, elimination of cannabis use might reduce the incidence of schizophrenia by ∼8% if there is a causal relationship.71 In a study of 2400 young Germans, cannabis use was concluded to produce a moderate increase in the risk for psychotic symptoms (at follow-up 4 years later the adjusted odds ratio was 1.7), but to have a much stronger effect in those with evidence of predisposition for psychosis.73

Frontiers Gone to Pot A Review of the Association between Cannabis and Psychosis Addictive Disorders and Behavioral Dyscontrol

The evidence for the association between cannabis use and persistent psychosis comes from both cross-sectional studies (192–196) and longitudinal epidemiological studies, including the Swedish military conscript cohort (197–199), the Netherlands Mental Health Survey and Incidence Study (NEMESIS) (20), the German prospective Early Developmental Stages of Psychopathology Study (EDSP) (24), the Dunedin cohort (19, 200), and the Christchurch Health and Development Study (CHDS) birth cohort (23). ...

The EDSP study, which used in-person interviews in the assessment of 923 individuals from the general population (aged 14–24 years), showed that cannabis use was associated with an increased risk of psychotic symptoms and persistent use increased this risk further (28). Importantly, this study yields evidence for a unidirectional relationship between cannabis use and psychosis...

The Dunedin cohort study (19) examined data from 759 subjects of the population birth cohort comprising 1037 individuals born in Dunedin, New Zealand, in 1972–1973. The study collected information on psychotic symptoms at age 11, drug use at ages 15 and 18 years, and assessed psychiatric symptoms at age 26. Cannabis use by age 15 and 18 years was found to be associated with more schizophrenia symptoms at age 26 years; and the association remained significant despite controlling for the presence of psychotic symptoms at age 11 years. The association was also found to be stronger with earlier use. Those who used cannabis by age 15 years were also four times more likely to have a diagnosis of schizophreniform disorder...

Fergusson et al. attempted to validate a possible causal link between cannabis use and psychosis in a dataset of a 25-year longitudinal study in New Zealand (the CHDS birth cohort comprising 1265 children) (23). The study showed that daily use of cannabis was associated with 2.3- to 3.3-fold higher risk of psychosis than among non-users. One of the limitations of the study is that the data was derived from 10 items of the Symptom Checklist-90, the items on which overlap with personality traits such as schizotypy and paranoia and that the study did not attempt to delineate psychotic symptoms due to the acute effects of cannabis use from persistent effects (204).

This finding of increased psychosis risk has been reported in several other prospective studies (19–21, 24). The cumulative evidence for the association between cannabis and psychosis have been examined in five systematic reviews (25, 205–208), four of which (25, 205, 207, 208) found a consistent association between cannabis use and psychosis...

Age of Exposure

Epidemiological evidence suggest that the earlier the age of exposure to cannabis, the greater the risk of a psychosis outcome (19). Dragt et al. showed that younger age of onset of cannabis use is associated with earlier symptoms of anxiety, social withdrawal, derealization, memory impairment, and difficulties in concentration, with effects being more pronounced in patients with heavier cannabis use (250). Another recent study found that early onset cannabis use was only associated with earlier onset of psychosis when cannabis use began by age 14 (251). A large meta-analysis of 83 studies found that the age of onset of psychosis in cannabis users was 2.7 years younger than in non-users (252). Animal studies have shown that exposure to cannabinoids in adolescence has more deleterious effects than exposure in adulthood (253–257). ...

Further studies that have followed patients over time have shown that among patients who are admitted with an initial diagnosis of cannabis-induced psychosis, almost 50% convert to schizophrenia or some other psychotic disorder (181, 188). Boydell et al., found, in a retrospective study of 757 first-episode schizophrenia patients (24% who used cannabis in the year prior to presentation), that among patients with schizophrenia, cannabis users did not differ significantly from those not using cannabis in terms of a positive family history of schizophrenia (15 vs. 12%) (274)...

Temporal Relationship

As discussed above, evidence from experimental studies shows a clear temporal relationship between exposure to cannabinoids and symptoms of psychosis. Despite a number of limitations (discussed previously), several epidemiological studies have concluded that cannabis use generally precedes the development of psychotic disorder. In one of the earliest such studies, Allebeck and colleagues found that cannabis use preceded the onset of schizophrenia by at least 1 year in 69% of cases; in only 11% of cases did cannabis succeed psychosis (309). In a prospective cohort study, Linszen et al. found that in all but 1 patient from a sample of 24 cannabis-abusing patients, cannabis abuse preceded FEP by at least 1 year (310).

Studies from recent years suggest that in the majority of cases, cannabis use precedes the onset of psychosis, rather than vice versa. In a study of 28 FEP patients, cannabis use preceded psychosis in all patients (267). Another study of 45 psychotic disorder patients with a history of cannabis use showed that the onset of cannabis use preceded hallucinations in 74% of cases and preceded persecutory ideas in 90% of cases by at least on year (250). Schimmelmann and associates (251) reported that in 88% of cases (n = 201 FEP patients with cannabis use), drug exposure preceded psychotic symptoms by a mean of 5 years. ...

In a longitudinal study of over 18,000 patients hospitalized for substance-induced psychosis, the 8-year cumulative risk of conversion to schizophrenia was 46% when the offending substance was cannabis. In contrast, the conversion rate to schizophrenia over the same period of time for alcohol-induced psychosis was 5%. Notably, the risk for the development of schizophrenia when the diagnosis was amphetamine-induced psychosis was 30% (188). ...

In summary, the relationship between cannabinoids and psychosis fulfills many but not all of the traditional criteria for causality. Given the evidence presented above, it is likely that cannabis is an important component cause in the development of psychotic disorders (16, 205)...

Cannabis May Cause Schizophrenia-Like Brain Changes Psych Central

Normally, specific parts of the brain are tuned into each another at certain frequencies, say the researchers. This rhythmic activity produces brain waves and allows information to be processed in order for us to react.

The team used the analogy of an orchestra to explain how this works. They say that brain activity can be compared to the performance of an orchestra in which string, brass, woodwind and percussion sections are joined together in rhythms dictated by the conductor. In a similar way, specific structures in the brain tune in to one another at certain frequencies. Their rhythmic activity creates brain waves, and the tuning of these brain waves normally allows information to be processed that guides our behavior. But cannabis causes disturbances in systems involved in concentration and memory, the team found.

The primary psychoactive ingredient of cannabis, known as THC, activates cannabinoid receptors, which are found in many brain areas. In the research, the team measured the electrical activity from hundreds of neurons in rats when given a drug similar to THC which also stimulates cannabinoid receptors.

This showed that the effects on individual brain regions were subtle, but brain waves across the hippocampus and prefrontal cortex were completely disrupted. These two brain areas are vital for memory and decision-making, so the rats were no longer able to accurately navigate a maze. Both areas are also involved in schizophrenia.

Marijuana use by teens linked to permanent brain abnormalities later in life increased schizophrenia risk study National Post

Marijuana use by teens linked to permanent brain abnormalities later in life, increased schizophrenia risk: study

Smoking a few joints with friends growing up may be the furthest thing from harmless for developing young brains, a new U.S. study suggests.

Teenagers who regularly use cannabis during their adolescent years may cause permanent brain abnormalities by using the drug, and increase their risk of developing serious mental disorders such as schizophrenia, a study published this month in the journal Neuropsychopharmacology, a division of the journal Nature, hints at.

The study, conducted by researchers at the University of Maryland School of Medicine, examined the cortical oscillations in mice. Cortical oscillations (patterns of activity of neurons in the brain believed to underlie various functions) are very abnormal in schizophrenia and in other psychiatric disorders. Scientists exposed young mice to very low doses of the active ingredient in marijuana for 20 days, and then allowed them to return to their siblings and develop normally.

“In the adult mice exposed to marijuana ingredients in adolescence, we found that cortical oscillations were grossly altered, and they exhibited impaired cognitive abilities,” says the study’s lead author, Sylvina Mullins Raver, a PhD candidate in neuroscience and neurobiology at the University of Maryland, in a press release with the study...

...i smoked the stuff quite often for at least 25-30 years .....i never knew anyone who developed mental problems or health problems who just smoked pot .....many of those people are doing quite well today....

That is probably because those that smoked pot and became mentally ill became isolated from your peer group. If you at a younger age had never smoked pot and read all these studies and warnings showing you were at a much greater risk of becoming mentally ill for life, would you take that chance?

now....the people i knew who did other drugs like speed or coke pretty frequently as well as pot or who Drank a lot.....many of those ones had problems.....some died over the years.....others became low income or just useless people.....no one seems to say that other drugs were being used by all these people who had health problems or who died.....and thats not sayin that someone just might have a shitty reaction to smoking pot.....that is very possible......most people who just smoked pot normally,not heavy smokers, had next to no problems....

From my considerable experience of taking drugs in my late teens and early twenties, I can see now how marijuana is a gateway drug, therefore pot is still to blame. I stopped taking all drugs at the age of twenty-four.

Everyone I knew was not satisfied with just pot.

 

[Delta4Embassy]

Would htink for every anti-cannabis study there's more like 50 pro ones.

 

[Moonglow]

I've smoked weed for 28 years and I have yet had a schizoid occurrence. I am happy that I live in a split level head...

 

[Delta4Embassy]

I've smoked weed for 28 years and I have yet had a schizoid occurrence. I am happy that I live in a split level head...

...That explains a lot.

 

[Moonglow]

I tried to live the button down Manhattan life, nah, seems like a waste to play keep up with the Jones and hate everybody for some reason type of human evolution..

 

[QuickHitCurepon]

Would htink for every anti-cannabis study there's more like 50 pro ones.

Post them and let's see just how legitimate they are.

 

[Harry Dresden]

Israeli researchers have been studying cannabis for over 50 years. Unlike most pharmaceuticals, it's benefits FAR exceed its' risks. You can die from drinking too much water (water intoxication et al.) even the OP article conceeds you can't overdose from cannabis.

What risk or fate could be worse than psychosis or schizophrenia?

and how often does that happen?

Very often if it doubles the risk.

Federal Report Marijuana Causes Mental Illness

May 3, 2005 -- Children who use marijuana before age 12 are twice as likely to later develop serious mental illness as those who don't try the drug until they're 18, according to a federal report released Tuesday.

Bush administration officials pointed to the study as growing evidence that smoking marijuana may cause mental illnesses -- including depression, schizophrenia, and suicide attempts -- in some people.

• It doubles risk of developing psychotic disorders, including schizophrenia

The terrible truth about cannabis Expert s devastating 20-year study finally demolishes claims that smoking pot is harmless Daily Mail Online

NAMI Marijuana and Mental Illness

Certainly not all people who smoke marijuana will develop schizophrenia, but people who are at risk of developing this illness—including individuals with close family relatives that have severe mental illness—will be more likely to experience psychosis if they are using marijuana.

Regular marijuana use bad for teens brains study finds -- ScienceDaily

Frequent marijuana use can have a significant negative effect on the brains of teenagers and young adults, including cognitive decline, poor attention and memory, and decreased IQ, according to psychologists discussing public health implications of marijuana legalization at the American Psychological Association's 122nd Annual Convention. ...

Some research has shown that frequent use of high potency THC can increase risk of acute and future problems with depression, anxiety and psychosis...

Smoking marijuana has been linked with an increased risk of mental illness, and now researchers say that when pot smokers do become mentally ill, the disease starts earlier than it would if they didn't smoke pot.

This means that serious psychiatric diseases that might not have shown up until kids were in their teens or twenties - or might never had developed at all are starting in children as young as 12 who smoke marijuana. ...

Smoking Pot May Hasten Onset of Mental Illness Fox News

you do realize for just about every anti-pot "study"......there is a pro-pot "study" that counters it.

And yet you have posted links to no such studies. I have seen only one study posted that counters the widespread belief that marijuana causes schizophrenia. Sorry, but one study does not counter widespread knowledge.

Marijuana and Schizophrenia 8211 A Clear and Unmistakable Link 8230 ignored in America Warm Southern Breeze

Marijuana and Schizophrenia – A Clear and Unmistakable Link… ignored in America
April 20, 2010

There is a significant and growing scientific body of medical evidence that marijuana use contributes significantly to schizophrenia – a particularly debilitating mental health condition that strikes during the most productive years of one’s life.

Medical marijuana anyone?

Maybe you’d prefer your mental health, instead.

It’s a shame that mental health professionals and other researchers in the United States almost wholly ignore the vast, longitudinal (long-term) and increasing body of evidence that conclusively demonstrates that marijuana DIRECTLY contributes to schizophrenia. ...

• Cannabis and schizophrenia. A longitudinal study. – Lancet, 1987 – 15 yr, 45,570 subject study of Swedish soldiers demonstrated significant risk for schizophrenia when compared to non-users and controlled for other factors, increased the risk of suicide 400%

• A 35-year longitudinal study published in the British Journal of Psychiatry, found that schizophrenia rates doubled among marijuana users in South London. 2003 Jan 1 ; 182():45-9

• Professor Jim van Os, Lead Researcher University of Maastricht, Netherlands followed 2437 people aged 14 – 24 four years. Findings published in the British Medical Journal revealed that controlled for other events, 51% of cannabis users experienced schizophrenic symptoms versus 26% of non-users.

• Robin Murray, Institute of Psychiatry, London, UK, found that cannabis smoking accounts for about 8% of serious cases of psychosis.

• Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident case. Br J Psychiatry. 2005 Dec;187:510-5 [Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders follow-up study of 535 incident cases ]

The environment and schizophrenia: the role of cannabis use. Schizophr Bull. 2005 Jul;31(3):608-12. Epub 2005 Jun 23. [ The environment and schizophrenia the role o... Schizophr Bull. 2005 - PubMed - NCBI ]

Predictors of schizophrenia–a review.
 Br Med Bull. 2005 Jun 9;73:1-15. Print 2005.

Cannabis as a risk factor for psychosis: systematic review.
 J Psychopharmacol. 2005 Mar;19(2):187-94.

[Acute and chronic cognitive disorders caused by cannabis use] Rev Prat. 2005 Jan 15;55(1):23-6; discussion 27-9. French.

NAMI Blog Marijuana and the Risk of Schizophrenia

Marijuana and the risk of schizophrenia
Mar 31, 2011
By Ken Duckworth, M.D., NAMI Medical Director

The ongoing link between use of marijuana in teens and the increased risk of developing schizophrenia has been further developed in a recent Dutch study published in the British Medical Journal (BMJ) and has re-ignited that area of interest...

The BMJ study looked at young adults who were at risk for psychosis and found that the rate of conversion to the illness was 51 percent with marijuana users-compared with 26 percent of nonusers. This study builds upon a growing body of literature that is making this causative link. This build upon other studies-one of the most interesting to me was a study that made a case for delaying all experimentation---the study found that users before age 15 were 4.5 times more likely to develop schizophrenia than nonsmokers, and those who delayed until age 18 had a risk of 1.6. This strongly suggests that, in addition to abstinence, delaying experimentation results in reduced risk. ...

Does using marijuana increase the risk for developing schizophrenia Portal de Pesquisa da BVS

As more US states and other countries consider legalizing marijuana, clinicians need to know the possible effects of this drug. Research has shown a connection between marijuana use and an increased risk for schizophrenia in young people who are vulnerable to developing psychosis. An international panel of experts addresses topics such as risk factors for schizophrenia, the potency and effects of cannabis use on adolescents, the effects of concurrent drug use with cannabis on schizophrenia risk, and current attitudes toward marijuana.

Predictors of schizophrenia a review

In a review by Arseneault et al.71 of five prospective population-based studies, cannabis use was estimated to confer an overall 2-fold increase in the relative risk for later schizophrenia on an individual level. In particular, those cannabis smokers who have genetic vulnerability or some baseline psychiatric symptoms have increased risk of schizophrenia.72 At the population level, elimination of cannabis use might reduce the incidence of schizophrenia by ∼8% if there is a causal relationship.71 In a study of 2400 young Germans, cannabis use was concluded to produce a moderate increase in the risk for psychotic symptoms (at follow-up 4 years later the adjusted odds ratio was 1.7), but to have a much stronger effect in those with evidence of predisposition for psychosis.73

Frontiers Gone to Pot A Review of the Association between Cannabis and Psychosis Addictive Disorders and Behavioral Dyscontrol

The evidence for the association between cannabis use and persistent psychosis comes from both cross-sectional studies (192–196) and longitudinal epidemiological studies, including the Swedish military conscript cohort (197–199), the Netherlands Mental Health Survey and Incidence Study (NEMESIS) (20), the German prospective Early Developmental Stages of Psychopathology Study (EDSP) (24), the Dunedin cohort (19, 200), and the Christchurch Health and Development Study (CHDS) birth cohort (23). ...

The EDSP study, which used in-person interviews in the assessment of 923 individuals from the general population (aged 14–24 years), showed that cannabis use was associated with an increased risk of psychotic symptoms and persistent use increased this risk further (28). Importantly, this study yields evidence for a unidirectional relationship between cannabis use and psychosis...

The Dunedin cohort study (19) examined data from 759 subjects of the population birth cohort comprising 1037 individuals born in Dunedin, New Zealand, in 1972–1973. The study collected information on psychotic symptoms at age 11, drug use at ages 15 and 18 years, and assessed psychiatric symptoms at age 26. Cannabis use by age 15 and 18 years was found to be associated with more schizophrenia symptoms at age 26 years; and the association remained significant despite controlling for the presence of psychotic symptoms at age 11 years. The association was also found to be stronger with earlier use. Those who used cannabis by age 15 years were also four times more likely to have a diagnosis of schizophreniform disorder...

Fergusson et al. attempted to validate a possible causal link between cannabis use and psychosis in a dataset of a 25-year longitudinal study in New Zealand (the CHDS birth cohort comprising 1265 children) (23). The study showed that daily use of cannabis was associated with 2.3- to 3.3-fold higher risk of psychosis than among non-users. One of the limitations of the study is that the data was derived from 10 items of the Symptom Checklist-90, the items on which overlap with personality traits such as schizotypy and paranoia and that the study did not attempt to delineate psychotic symptoms due to the acute effects of cannabis use from persistent effects (204).

This finding of increased psychosis risk has been reported in several other prospective studies (19–21, 24). The cumulative evidence for the association between cannabis and psychosis have been examined in five systematic reviews (25, 205–208), four of which (25, 205, 207, 208) found a consistent association between cannabis use and psychosis...

Age of Exposure

Epidemiological evidence suggest that the earlier the age of exposure to cannabis, the greater the risk of a psychosis outcome (19). Dragt et al. showed that younger age of onset of cannabis use is associated with earlier symptoms of anxiety, social withdrawal, derealization, memory impairment, and difficulties in concentration, with effects being more pronounced in patients with heavier cannabis use (250). Another recent study found that early onset cannabis use was only associated with earlier onset of psychosis when cannabis use began by age 14 (251). A large meta-analysis of 83 studies found that the age of onset of psychosis in cannabis users was 2.7 years younger than in non-users (252). Animal studies have shown that exposure to cannabinoids in adolescence has more deleterious effects than exposure in adulthood (253–257). ...

Further studies that have followed patients over time have shown that among patients who are admitted with an initial diagnosis of cannabis-induced psychosis, almost 50% convert to schizophrenia or some other psychotic disorder (181, 188). Boydell et al., found, in a retrospective study of 757 first-episode schizophrenia patients (24% who used cannabis in the year prior to presentation), that among patients with schizophrenia, cannabis users did not differ significantly from those not using cannabis in terms of a positive family history of schizophrenia (15 vs. 12%) (274)...

Temporal Relationship

As discussed above, evidence from experimental studies shows a clear temporal relationship between exposure to cannabinoids and symptoms of psychosis. Despite a number of limitations (discussed previously), several epidemiological studies have concluded that cannabis use generally precedes the development of psychotic disorder. In one of the earliest such studies, Allebeck and colleagues found that cannabis use preceded the onset of schizophrenia by at least 1 year in 69% of cases; in only 11% of cases did cannabis succeed psychosis (309). In a prospective cohort study, Linszen et al. found that in all but 1 patient from a sample of 24 cannabis-abusing patients, cannabis abuse preceded FEP by at least 1 year (310).

Studies from recent years suggest that in the majority of cases, cannabis use precedes the onset of psychosis, rather than vice versa. In a study of 28 FEP patients, cannabis use preceded psychosis in all patients (267). Another study of 45 psychotic disorder patients with a history of cannabis use showed that the onset of cannabis use preceded hallucinations in 74% of cases and preceded persecutory ideas in 90% of cases by at least on year (250). Schimmelmann and associates (251) reported that in 88% of cases (n = 201 FEP patients with cannabis use), drug exposure preceded psychotic symptoms by a mean of 5 years. ...

In a longitudinal study of over 18,000 patients hospitalized for substance-induced psychosis, the 8-year cumulative risk of conversion to schizophrenia was 46% when the offending substance was cannabis. In contrast, the conversion rate to schizophrenia over the same period of time for alcohol-induced psychosis was 5%. Notably, the risk for the development of schizophrenia when the diagnosis was amphetamine-induced psychosis was 30% (188). ...

In summary, the relationship between cannabinoids and psychosis fulfills many but not all of the traditional criteria for causality. Given the evidence presented above, it is likely that cannabis is an important component cause in the development of psychotic disorders (16, 205)...

Cannabis May Cause Schizophrenia-Like Brain Changes Psych Central

Normally, specific parts of the brain are tuned into each another at certain frequencies, say the researchers. This rhythmic activity produces brain waves and allows information to be processed in order for us to react.

The team used the analogy of an orchestra to explain how this works. They say that brain activity can be compared to the performance of an orchestra in which string, brass, woodwind and percussion sections are joined together in rhythms dictated by the conductor. In a similar way, specific structures in the brain tune in to one another at certain frequencies. Their rhythmic activity creates brain waves, and the tuning of these brain waves normally allows information to be processed that guides our behavior. But cannabis causes disturbances in systems involved in concentration and memory, the team found.

The primary psychoactive ingredient of cannabis, known as THC, activates cannabinoid receptors, which are found in many brain areas. In the research, the team measured the electrical activity from hundreds of neurons in rats when given a drug similar to THC which also stimulates cannabinoid receptors.

This showed that the effects on individual brain regions were subtle, but brain waves across the hippocampus and prefrontal cortex were completely disrupted. These two brain areas are vital for memory and decision-making, so the rats were no longer able to accurately navigate a maze. Both areas are also involved in schizophrenia.

Marijuana use by teens linked to permanent brain abnormalities later in life increased schizophrenia risk study National Post

Marijuana use by teens linked to permanent brain abnormalities later in life, increased schizophrenia risk: study

Smoking a few joints with friends growing up may be the furthest thing from harmless for developing young brains, a new U.S. study suggests.

Teenagers who regularly use cannabis during their adolescent years may cause permanent brain abnormalities by using the drug, and increase their risk of developing serious mental disorders such as schizophrenia, a study published this month in the journal Neuropsychopharmacology, a division of the journal Nature, hints at.

The study, conducted by researchers at the University of Maryland School of Medicine, examined the cortical oscillations in mice. Cortical oscillations (patterns of activity of neurons in the brain believed to underlie various functions) are very abnormal in schizophrenia and in other psychiatric disorders. Scientists exposed young mice to very low doses of the active ingredient in marijuana for 20 days, and then allowed them to return to their siblings and develop normally.

“In the adult mice exposed to marijuana ingredients in adolescence, we found that cortical oscillations were grossly altered, and they exhibited impaired cognitive abilities,” says the study’s lead author, Sylvina Mullins Raver, a PhD candidate in neuroscience and neurobiology at the University of Maryland, in a press release with the study...

...i smoked the stuff quite often for at least 25-30 years .....i never knew anyone who developed mental problems or health problems who just smoked pot .....many of those people are doing quite well today....

That is probably because those that smoked pot and became mentally ill became isolated from your peer group. If you at a younger age had never smoked pot and read all these studies and warnings showing you were at a much greater risk of becoming mentally ill for life, would you take that chance?

now....the people i knew who did other drugs like speed or coke pretty frequently as well as pot or who Drank a lot.....many of those ones had problems.....some died over the years.....others became low income or just useless people.....no one seems to say that other drugs were being used by all these people who had health problems or who died.....and thats not sayin that someone just might have a shitty reaction to smoking pot.....that is very possible......most people who just smoked pot normally,not heavy smokers, had next to no problems....

From my considerable experience of taking drugs in my late teens and early twenties, I can see now how marijuana is a gateway drug, therefore pot is still to blame. I stopped taking all drugs at the age of twenty-four.

Everyone I knew was not satisfied with just pot.

That is probably because those that smoked pot and became mentally ill became isolated from your peer group.

oh is that what happened?....i knew them even beyond the smoking years....no mental illness....try again....

gateway drug?.....most of the guys i knew were either smoking cigarets or drinking before we seen pot in our first year of collage...some of them were doing "whites" before pot too....the word gateway is over exaggerated....

 

[Harry Dresden]

Cannabis is too much ingrained in the "legal" system as a cash cow to be easily legislated into legal use globally. LEO, lawyers, bondsmen, court staff, judges, prison staff, supporting contractors...all benefit from the prosecution of cannabis infractions, once defined in some states to mean the possession of one seed could lead to a felony conviction.

It's always going to be a money game. The lawyers and the "legal" system will always get richer!

and those same people you mentioned will still continue to smoke it themselves.....

Hey! Cops have the best weed in town! I know a lawyer back home that keeps a pot plant in his office. It's all a money game!

i was at a party at a Lawyers nice big house in Newport Beach were i was in the backyard getting high with that lawyer,a Superior Court Judge and a few other people in their profession....i did not know who they were until the dude i went to the party with told me.....he worked in the law office....

 

[SmarterThanTheAverageBear]

What risk or fate could be worse than psychosis or schizophrenia?

and how often does that happen?

Very often if it doubles the risk.

Federal Report Marijuana Causes Mental Illness

May 3, 2005 -- Children who use marijuana before age 12 are twice as likely to later develop serious mental illness as those who don't try the drug until they're 18, according to a federal report released Tuesday.

Bush administration officials pointed to the study as growing evidence that smoking marijuana may cause mental illnesses -- including depression, schizophrenia, and suicide attempts -- in some people.

• It doubles risk of developing psychotic disorders, including schizophrenia

The terrible truth about cannabis Expert s devastating 20-year study finally demolishes claims that smoking pot is harmless Daily Mail Online

NAMI Marijuana and Mental Illness

Certainly not all people who smoke marijuana will develop schizophrenia, but people who are at risk of developing this illness—including individuals with close family relatives that have severe mental illness—will be more likely to experience psychosis if they are using marijuana.

Regular marijuana use bad for teens brains study finds -- ScienceDaily

Frequent marijuana use can have a significant negative effect on the brains of teenagers and young adults, including cognitive decline, poor attention and memory, and decreased IQ, according to psychologists discussing public health implications of marijuana legalization at the American Psychological Association's 122nd Annual Convention. ...

Some research has shown that frequent use of high potency THC can increase risk of acute and future problems with depression, anxiety and psychosis...

Smoking marijuana has been linked with an increased risk of mental illness, and now researchers say that when pot smokers do become mentally ill, the disease starts earlier than it would if they didn't smoke pot.

This means that serious psychiatric diseases that might not have shown up until kids were in their teens or twenties - or might never had developed at all are starting in children as young as 12 who smoke marijuana. ...

Smoking Pot May Hasten Onset of Mental Illness Fox News

you do realize for just about every anti-pot "study"......there is a pro-pot "study" that counters it.

And yet you have posted links to no such studies. I have seen only one study posted that counters the widespread belief that marijuana causes schizophrenia. Sorry, but one study does not counter widespread knowledge.

Marijuana and Schizophrenia 8211 A Clear and Unmistakable Link 8230 ignored in America Warm Southern Breeze

Marijuana and Schizophrenia – A Clear and Unmistakable Link… ignored in America
April 20, 2010

There is a significant and growing scientific body of medical evidence that marijuana use contributes significantly to schizophrenia – a particularly debilitating mental health condition that strikes during the most productive years of one’s life.

Medical marijuana anyone?

Maybe you’d prefer your mental health, instead.

It’s a shame that mental health professionals and other researchers in the United States almost wholly ignore the vast, longitudinal (long-term) and increasing body of evidence that conclusively demonstrates that marijuana DIRECTLY contributes to schizophrenia. ...

• Cannabis and schizophrenia. A longitudinal study. – Lancet, 1987 – 15 yr, 45,570 subject study of Swedish soldiers demonstrated significant risk for schizophrenia when compared to non-users and controlled for other factors, increased the risk of suicide 400%

• A 35-year longitudinal study published in the British Journal of Psychiatry, found that schizophrenia rates doubled among marijuana users in South London. 2003 Jan 1 ; 182():45-9

• Professor Jim van Os, Lead Researcher University of Maastricht, Netherlands followed 2437 people aged 14 – 24 four years. Findings published in the British Medical Journal revealed that controlled for other events, 51% of cannabis users experienced schizophrenic symptoms versus 26% of non-users.

• Robin Murray, Institute of Psychiatry, London, UK, found that cannabis smoking accounts for about 8% of serious cases of psychosis.

• Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident case. Br J Psychiatry. 2005 Dec;187:510-5 [Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders follow-up study of 535 incident cases ]

The environment and schizophrenia: the role of cannabis use. Schizophr Bull. 2005 Jul;31(3):608-12. Epub 2005 Jun 23. [ The environment and schizophrenia the role o... Schizophr Bull. 2005 - PubMed - NCBI ]

Predictors of schizophrenia–a review.
 Br Med Bull. 2005 Jun 9;73:1-15. Print 2005.

Cannabis as a risk factor for psychosis: systematic review.
 J Psychopharmacol. 2005 Mar;19(2):187-94.

[Acute and chronic cognitive disorders caused by cannabis use] Rev Prat. 2005 Jan 15;55(1):23-6; discussion 27-9. French.

NAMI Blog Marijuana and the Risk of Schizophrenia

Marijuana and the risk of schizophrenia
Mar 31, 2011
By Ken Duckworth, M.D., NAMI Medical Director

The ongoing link between use of marijuana in teens and the increased risk of developing schizophrenia has been further developed in a recent Dutch study published in the British Medical Journal (BMJ) and has re-ignited that area of interest...

The BMJ study looked at young adults who were at risk for psychosis and found that the rate of conversion to the illness was 51 percent with marijuana users-compared with 26 percent of nonusers. This study builds upon a growing body of literature that is making this causative link. This build upon other studies-one of the most interesting to me was a study that made a case for delaying all experimentation---the study found that users before age 15 were 4.5 times more likely to develop schizophrenia than nonsmokers, and those who delayed until age 18 had a risk of 1.6. This strongly suggests that, in addition to abstinence, delaying experimentation results in reduced risk. ...

Does using marijuana increase the risk for developing schizophrenia Portal de Pesquisa da BVS

As more US states and other countries consider legalizing marijuana, clinicians need to know the possible effects of this drug. Research has shown a connection between marijuana use and an increased risk for schizophrenia in young people who are vulnerable to developing psychosis. An international panel of experts addresses topics such as risk factors for schizophrenia, the potency and effects of cannabis use on adolescents, the effects of concurrent drug use with cannabis on schizophrenia risk, and current attitudes toward marijuana.

Predictors of schizophrenia a review

In a review by Arseneault et al.71 of five prospective population-based studies, cannabis use was estimated to confer an overall 2-fold increase in the relative risk for later schizophrenia on an individual level. In particular, those cannabis smokers who have genetic vulnerability or some baseline psychiatric symptoms have increased risk of schizophrenia.72 At the population level, elimination of cannabis use might reduce the incidence of schizophrenia by ∼8% if there is a causal relationship.71 In a study of 2400 young Germans, cannabis use was concluded to produce a moderate increase in the risk for psychotic symptoms (at follow-up 4 years later the adjusted odds ratio was 1.7), but to have a much stronger effect in those with evidence of predisposition for psychosis.73

Frontiers Gone to Pot A Review of the Association between Cannabis and Psychosis Addictive Disorders and Behavioral Dyscontrol

The evidence for the association between cannabis use and persistent psychosis comes from both cross-sectional studies (192–196) and longitudinal epidemiological studies, including the Swedish military conscript cohort (197–199), the Netherlands Mental Health Survey and Incidence Study (NEMESIS) (20), the German prospective Early Developmental Stages of Psychopathology Study (EDSP) (24), the Dunedin cohort (19, 200), and the Christchurch Health and Development Study (CHDS) birth cohort (23). ...

The EDSP study, which used in-person interviews in the assessment of 923 individuals from the general population (aged 14–24 years), showed that cannabis use was associated with an increased risk of psychotic symptoms and persistent use increased this risk further (28). Importantly, this study yields evidence for a unidirectional relationship between cannabis use and psychosis...

The Dunedin cohort study (19) examined data from 759 subjects of the population birth cohort comprising 1037 individuals born in Dunedin, New Zealand, in 1972–1973. The study collected information on psychotic symptoms at age 11, drug use at ages 15 and 18 years, and assessed psychiatric symptoms at age 26. Cannabis use by age 15 and 18 years was found to be associated with more schizophrenia symptoms at age 26 years; and the association remained significant despite controlling for the presence of psychotic symptoms at age 11 years. The association was also found to be stronger with earlier use. Those who used cannabis by age 15 years were also four times more likely to have a diagnosis of schizophreniform disorder...

Fergusson et al. attempted to validate a possible causal link between cannabis use and psychosis in a dataset of a 25-year longitudinal study in New Zealand (the CHDS birth cohort comprising 1265 children) (23). The study showed that daily use of cannabis was associated with 2.3- to 3.3-fold higher risk of psychosis than among non-users. One of the limitations of the study is that the data was derived from 10 items of the Symptom Checklist-90, the items on which overlap with personality traits such as schizotypy and paranoia and that the study did not attempt to delineate psychotic symptoms due to the acute effects of cannabis use from persistent effects (204).

This finding of increased psychosis risk has been reported in several other prospective studies (19–21, 24). The cumulative evidence for the association between cannabis and psychosis have been examined in five systematic reviews (25, 205–208), four of which (25, 205, 207, 208) found a consistent association between cannabis use and psychosis...

Age of Exposure

Epidemiological evidence suggest that the earlier the age of exposure to cannabis, the greater the risk of a psychosis outcome (19). Dragt et al. showed that younger age of onset of cannabis use is associated with earlier symptoms of anxiety, social withdrawal, derealization, memory impairment, and difficulties in concentration, with effects being more pronounced in patients with heavier cannabis use (250). Another recent study found that early onset cannabis use was only associated with earlier onset of psychosis when cannabis use began by age 14 (251). A large meta-analysis of 83 studies found that the age of onset of psychosis in cannabis users was 2.7 years younger than in non-users (252). Animal studies have shown that exposure to cannabinoids in adolescence has more deleterious effects than exposure in adulthood (253–257). ...

Further studies that have followed patients over time have shown that among patients who are admitted with an initial diagnosis of cannabis-induced psychosis, almost 50% convert to schizophrenia or some other psychotic disorder (181, 188). Boydell et al., found, in a retrospective study of 757 first-episode schizophrenia patients (24% who used cannabis in the year prior to presentation), that among patients with schizophrenia, cannabis users did not differ significantly from those not using cannabis in terms of a positive family history of schizophrenia (15 vs. 12%) (274)...

Temporal Relationship

As discussed above, evidence from experimental studies shows a clear temporal relationship between exposure to cannabinoids and symptoms of psychosis. Despite a number of limitations (discussed previously), several epidemiological studies have concluded that cannabis use generally precedes the development of psychotic disorder. In one of the earliest such studies, Allebeck and colleagues found that cannabis use preceded the onset of schizophrenia by at least 1 year in 69% of cases; in only 11% of cases did cannabis succeed psychosis (309). In a prospective cohort study, Linszen et al. found that in all but 1 patient from a sample of 24 cannabis-abusing patients, cannabis abuse preceded FEP by at least 1 year (310).

Studies from recent years suggest that in the majority of cases, cannabis use precedes the onset of psychosis, rather than vice versa. In a study of 28 FEP patients, cannabis use preceded psychosis in all patients (267). Another study of 45 psychotic disorder patients with a history of cannabis use showed that the onset of cannabis use preceded hallucinations in 74% of cases and preceded persecutory ideas in 90% of cases by at least on year (250). Schimmelmann and associates (251) reported that in 88% of cases (n = 201 FEP patients with cannabis use), drug exposure preceded psychotic symptoms by a mean of 5 years. ...

In a longitudinal study of over 18,000 patients hospitalized for substance-induced psychosis, the 8-year cumulative risk of conversion to schizophrenia was 46% when the offending substance was cannabis. In contrast, the conversion rate to schizophrenia over the same period of time for alcohol-induced psychosis was 5%. Notably, the risk for the development of schizophrenia when the diagnosis was amphetamine-induced psychosis was 30% (188). ...

In summary, the relationship between cannabinoids and psychosis fulfills many but not all of the traditional criteria for causality. Given the evidence presented above, it is likely that cannabis is an important component cause in the development of psychotic disorders (16, 205)...

Cannabis May Cause Schizophrenia-Like Brain Changes Psych Central

Normally, specific parts of the brain are tuned into each another at certain frequencies, say the researchers. This rhythmic activity produces brain waves and allows information to be processed in order for us to react.

The team used the analogy of an orchestra to explain how this works. They say that brain activity can be compared to the performance of an orchestra in which string, brass, woodwind and percussion sections are joined together in rhythms dictated by the conductor. In a similar way, specific structures in the brain tune in to one another at certain frequencies. Their rhythmic activity creates brain waves, and the tuning of these brain waves normally allows information to be processed that guides our behavior. But cannabis causes disturbances in systems involved in concentration and memory, the team found.

The primary psychoactive ingredient of cannabis, known as THC, activates cannabinoid receptors, which are found in many brain areas. In the research, the team measured the electrical activity from hundreds of neurons in rats when given a drug similar to THC which also stimulates cannabinoid receptors.

This showed that the effects on individual brain regions were subtle, but brain waves across the hippocampus and prefrontal cortex were completely disrupted. These two brain areas are vital for memory and decision-making, so the rats were no longer able to accurately navigate a maze. Both areas are also involved in schizophrenia.

Marijuana use by teens linked to permanent brain abnormalities later in life increased schizophrenia risk study National Post

Marijuana use by teens linked to permanent brain abnormalities later in life, increased schizophrenia risk: study

Smoking a few joints with friends growing up may be the furthest thing from harmless for developing young brains, a new U.S. study suggests.

Teenagers who regularly use cannabis during their adolescent years may cause permanent brain abnormalities by using the drug, and increase their risk of developing serious mental disorders such as schizophrenia, a study published this month in the journal Neuropsychopharmacology, a division of the journal Nature, hints at.

The study, conducted by researchers at the University of Maryland School of Medicine, examined the cortical oscillations in mice. Cortical oscillations (patterns of activity of neurons in the brain believed to underlie various functions) are very abnormal in schizophrenia and in other psychiatric disorders. Scientists exposed young mice to very low doses of the active ingredient in marijuana for 20 days, and then allowed them to return to their siblings and develop normally.

“In the adult mice exposed to marijuana ingredients in adolescence, we found that cortical oscillations were grossly altered, and they exhibited impaired cognitive abilities,” says the study’s lead author, Sylvina Mullins Raver, a PhD candidate in neuroscience and neurobiology at the University of Maryland, in a press release with the study...

...i smoked the stuff quite often for at least 25-30 years .....i never knew anyone who developed mental problems or health problems who just smoked pot .....many of those people are doing quite well today....

That is probably because those that smoked pot and became mentally ill became isolated from your peer group. If you at a younger age had never smoked pot and read all these studies and warnings showing you were at a much greater risk of becoming mentally ill for life, would you take that chance?

now....the people i knew who did other drugs like speed or coke pretty frequently as well as pot or who Drank a lot.....many of those ones had problems.....some died over the years.....others became low income or just useless people.....no one seems to say that other drugs were being used by all these people who had health problems or who died.....and thats not sayin that someone just might have a shitty reaction to smoking pot.....that is very possible......most people who just smoked pot normally,not heavy smokers, had next to no problems....

From my considerable experience of taking drugs in my late teens and early twenties, I can see now how marijuana is a gateway drug, therefore pot is still to blame. I stopped taking all drugs at the age of twenty-four.

Everyone I knew was not satisfied with just pot.

That is probably because those that smoked pot and became mentally ill became isolated from your peer group.

oh is that what happened?....i knew them even beyond the smoking years....no mental illness....try again....

gateway drug?.....most of the guys i knew were either smoking cigarets or drinking before we seen pot in our first year of collage...some of them were doing "whites" before pot too....the word gateway is over exaggerated....

I believe it is a gateway to illicit drugs. Of course alcohol is the ultimate gateway though.

 

[QuickHitCurepon]

That is probably because those that smoked pot and became mentally ill became isolated from your peer group.

oh is that what happened?....i knew them even beyond the smoking years....no mental illness....try again....

That's not what I meant. You aren't friends with anyone mentally ill, right? If you are, ask them if they smoked pot before they got ill.