The straight dopamine theory could be up in smoke:

[viljo]

June 28, 2009
The straight dopamine theory could be up in smoke:
There is now growing evidence that cannabis use causes a small but reliable increase in the chance of developing psychosis. Traditionally, this was explained by the drug increasing dopamine levels in the brain but a new study shortly to be published in NeuroImage suggests that the active ingredient in cannabis doesn't effect this important neurotransmitter.
Despite some dissenting voices, disruption to the mesolimbic dopamine pathway is widely thought to be the key problem in the development of delusions, hallucinations and the other psychotic symptoms commonly diagnosed as schizophrenia.
This has led to the assumption that the small increased risk of psychosis reliably associated with cannabis use is due to the drug increasing dopamine levels in a deep brain structure called the striatum.
In itself, this is partly based on another assumption - the virtual mantra of recreational drug research that 'all drugs of abuse increase dopamine levels in the reward system' of which the striatum is a part.
This new study, led by neuroscientist Paul Stokes, tested dopamine levels by using a type of PET brain scan where participants are injected with a radioactive tracer that binds to free dopamine receptors. Higher dopamine levels will mean that there are less free dopamine receptors and, therefore, lower tracer levels.
Participants were tested twice, once when given placebo and once when given a dose of pure THC - one of the most important active ingredients in cannabis. The dose was designed to be roughly equivalent to the amount you might absorb from a single joint.
The researchers found no difference in dopamine levels between the THC and the sugar pill, even though the participants clearly reported the effects of the drug.
Although they only tested 13 participants, this is the largest study of its kind so far. These type of neurotransmitter tracer studies are know to produce conflicting results at times, so further experiments will be needed to be sure of the result.
But if it is the case that cannabis does not cause a significant increase in dopamine levels, this will mean our ideas about cannabis and psychosis will need a rethink.
It also shakes up the idea common idea that all recreational drugs are pleasurable because they affect the 'dopamine reward system'.

 

[Forkbender]

^could you please give a link to the source of this article?

There is now growing evidence that cannabis use causes a small but reliable increase in the chance of developing psychosis.

I would like to see this evidence, because I have never seen it before. I'd also like to see how they distinguish between psychotic people turning to cannabis and cannabis causing psychosis, as this is hard to determine post-factum.

The rest of the article doesn't explain this sentence, it just sits there, as a statement which has no reference and no proof. I thought the rest of the article interesting, and am curious to learn more about their method.

 

[restin]

I wouldn't talk about the schizophrenia but rather about the Dopamine...

...so we don't really know what cannabis does to the brain, do we?

 

[st.bot.32]

Some recent studies seem to indicate a link between cannabis users with schizophrenia and a certain type of gene that the average population doesn't have. The study I saw (posted it here a few weeks ago) showed a huge difference, there was a huge percentage of this small subset of people who had mental problems, however in the average population the difference in schizophrenia between cannabis smokers and abstainers was practically nonexistent.

Anyway these studies are so small (13 people isn't even a study). Once we start getting trials with hundreds of people we will know more.

 

[viljo]

http://www.mindhacks.com/blog/2009/06/t ... pamin.html

 

[st.bot.32]

Thanks for posting it, it is an interesting find

 

[IJesusChrist]

Good job Viljo! I'm glad you finally found this.

"A small but reliable increase in the chance of developing pyschosis"

It's an interesting topic, but when you really think about it, why wouldn't such a substance cause psychosis? Who is to say that the brain can tolerate long term, or even short term uses of a foreign substance, a non-traditional communicator in one's brain? It seems to me like, duh, there is always the possibility, you put something in your body, you are always going to have a small, even negligible risk, but there is that risk.

 

[Jeniger]

given a dose of pure THC - one of the most important active ingredients in cannabis. The dose was designed to be roughly equivalent to the amount you might absorb from a single joint.

How is this possible? How can you define the amount u might absorb from a joint? ingested in 1 time? A joint with tabacco? Doesnt that has effect on the dopamine system?

 

[Forkbender]

If it causes psychosis, then there must be a reason why not all users get psychosis. This reason can be genetic or environmental. If it is genetic, you might as well say that the psychosis is genetic and not caused by cannabis, so that leaves environmental causes for not having psychosis (for example nutrition). The people who don't get psychosis from smoking cannabis daily for 30 years aren't on anti-psychotic medicine, which means that there should be some natural anti-psychotic environmental conditions. If these conditions exist (as must be inferred from the assumption that cannabis causes psychosis), then why haven't they been discovered?

 

[forest]

there are several people i know who smoked a lot of weed, who got into a psychosis. it's not sure that if you smoke a lot of weed over a long period that you will definately will have a psychosis, but it's quite obvious that people who are sensitive to having a psychosis, smoking weed will excellerate the proces and make the chance of having one, way bigger.

edit; i don't think it's odd. people who are introvert, tend to isolate themselves more when smoking weed (i guess), and get more passive.

 

[mysticwarrior]

Hmmm, should we not first ask our self, what exactly defines a psychosis... I get the impression that people use this word to easily.

 

[restin]

Agreed...you first :wink:

 

[mysticwarrior]

Agreed...you first Wink

Please give me some TOXIC anti-psychotic pills! I just read the exact meaning on a dutch wiki page. And it seems that if i would diagnose my self, i would almost diagnose me as psychotic But i really do NOT have a problem with it, to be honest, i even like it In my case, i don't see the problem as long if i don't start to see things that aren't there, while i am not on entheogen's. And guess what, one of the symptoms that could occur if you are psychotic, is that you don't notice the problem, because of a lack of insight.

 

[mysticwarrior]

Psychosis appears as a symptom of a number of mental disorders, including mood and personality disorders, schizophrenia, delusional disorder, and substance abuse. It is also the defining feature of the psychotic disorders (i.e., brief psychotic disorder, shared psychotic disorder, psychotic disorder due to a general medical condition, and substance-induced psychotic disorder).

Patients suffering from psychosis are unable to distinguish the real from the unreal. They experience hallucinations and/or delusions that they believe are real, and they typically behave in an inappropriate and confused manner.

A mental illness can exhibited through various forms of psychosis, such as:

* Delusions.An unshakable and irrational belief in something untrue. Delusions defy normal reasoning, and remain firm even when overwhelming proof is presented to disprove them.
* Hallucinations.Psychosis causes false or distorted sensory experience that appear to be real. Psychotic patients often see, hear, smell, taste, or feel things that aren't there.
* Disorganized speech.Psychotic patients often speak incoherently, using noises instead of words and "talking" in unintelligible speech patterns.
* Disorganized or catatonic behavior.Behavior that is completely inappropriate to the situation or environment. Catatonic patients have either a complete lack of or inappropriate excess of motor activity. They can be completely rigid and unable to move (vegetative), or in constant motion. Disorganized behavior is unpredictable and inappropriate for a situation (such as screaming obscenities in the middle of class).

Paula Ford-Martin, M.A.

http://www.minddisorders.com/Ob-Ps/Psychosis.html

 

[restin]

haha then I conclude that our society is (philosophically) schizo... :lol:

 

[mysticwarrior]

haha then I conclude that our society is (philosophically) schizo... :lol:

:lol: That would at least explain a lot to me :lol:

 

[Kannibalkyle]

medical marijuana has actually meen used for epilepsy, OCD, bipolar i would like to see a link to where you got this information because withdraw for THC does not cause enough neurotic genouisis to have long term brain effects like schizophrenia , every minor effects of those like of schizophrenia but they are not long term or even close significant to what your saying. :?:

 

[BrainEater]

it's psychadelic so its for sure a catalyzer for something like schizophrenia. but it must be clear that it does NOT CAUSE it.

and like written above me marijuana IS used medically and it IS a healing plant, but as THC affects brain-chemistry it is no wonder that it can catalyze "mental illnesses like schizophrenia" if the neurotransmitter balancing schemes or the pools of chemicals get out of balance either by abuse of THC or by well whatever nutrition, sleeping patterns, endogenous hormone stress levels etc etc

and its no wonder as well that society nowadays represents growing numbers of psychotic ill people and well coincidentally i guess many of these would be slaves of the system..

peace

 

[Synith]

Well, or course. THC acts as Anandamide; binding to cannabinoid receptors, allowing Dopamine to squirt into the synapse. The Dopamine's already there, it's just inactive at until THC, or Anandamide binds to those receptors.

As for the Schizophrenia thing. That's subjective, really. You can't say 'Everyone who smokes pot is gonna loose their mind.' Because it doesn't always happen. Some may already have a gene in them prone to Schizophrenia and Cannabis may develop it further, producing a full-blown psychosis out of nowhere. Scientists have yet to realize that though everyone's bodies generally do the same thing when a chemical is introduced, the results aren't always the same. Especially if someone has a family history of psychosis present. We'll never fully understand.

it's psychadelic so its for sure a catalyzer for something like schizophrenia. but it must be clear that it does NOT CAUSE it.

and like written above me marijuana IS used medically and it IS a healing plant, but as THC affects brain-chemistry it is no wonder that it can catalyze "mental illnesses like schizophrenia" if the neurotransmitter balancing schemes or the pools of chemicals get out of balance either by abuse of THC or by well whatever nutrition, sleeping patterns, endogenous hormone stress levels etc etc

and its no wonder as well that society nowadays represents growing numbers of psychotic ill people and well coincidentally i guess many of these would be slaves of the system..

peace

+1

Only thing I've to disagree on is defining Cannabis as a psychedelic. It's really a drug of its own class, since it's so uniquely unlike any other; It's a psychoactive drug, but to me, not necessarily a psychedelic. :weedman:

 

[Synith]

given a dose of pure THC - one of the most important active ingredients in cannabis. The dose was designed to be roughly equivalent to the amount you might absorb from a single joint.

How is this possible? How can you define the amount u might absorb from a joint? ingested in 1 time? A joint with tabacco? Doesnt that has effect on the dopamine system?

I donno, man. It's hard to say. I suppose they took note of how much THC it takes to get a person really high. Or they're bullshitting. Who knows, haha. Studies with Cannabis have been with such a small number of people, it's appalling and disgraceful to the medical field. They do more tests with acetaminophen than tetrahydrocannabinol and other cannabinoids, like cannabidiol cannabinol and tetrahydrocannabivarin.

Anyhow. I'm not sure why you meant by tobacco, but nicotine, especially free-based nicotine interacts with a different region of the brain, releasing dopamine in a different area, since nicotine binds ironically to the nicotinic acetylcholine receptors. Nicotine does a lot more than that though: http://en.wikipedia.org/wiki/Nicotine#P ... ve_effects <<

If they are mixing their tests with tobacco, then it cannot be fully accountable. Tests should be done with what you intend to study, not with what you intend to study and something else.