Cannabis and Psychosis Diverse studies suggest that cannabis use is associated with psychotic phenomenology. First, in addition to being the most abused illicit substance in the general US population, cannabis is clearly the most abused illegal drug among individuals with schizophrenia.[1,2] Furthermore, the initiation of cannabis use among those with psychotic disorders often precedes the onset of psychosis by several years.[1,3,4] Second, cannabis use in adolescence is increasingly recognized as an independent risk factor for psychosis and schizophrenia.[5-7] That is, several epidemiologic studies suggest that cannabis use is a component cause of schizophrenia.[8,9] Very recently, McGrath and colleagues[10] reported that early cannabis use is associated with psychosis-related outcomes (having a nonaffective psychotic disorder, scoring in the highest quartile of the Peters Delusions Inventory,[11] and reporting hallucinations) in a cohort of 3801 individuals assessed at age 18-23 years. Findings among 228 sibling pairs in that study reduce the likelihood that unmeasured confounding variables account for the results.[10] Third, cannabis use may interact with genetic factors to elevate risk for psychotic disorders. One sentinel study demonstrated that the catechol-O-methyltransferase Val158Met functional polymorphism moderates the effects of adolescent-onset cannabis use on the later development of psychosis.[12] Fourth, preliminary research suggests that cannabis use before the manifestation of psychiatric symptoms may be associated with an earlier age at onset of psychotic symptoms,[13] and perhaps even an earlier onset of prodromal symptoms.[14] We found that simply classifying first-episode psychosis patients according to their maximum frequency of use before onset of psychotic symptoms (ie, categorizing into none, ever, weekly, or daily use) revealed no significant effects of cannabis use on risk for onset, but analyzing the change in frequency of use before onset (using time-dependent covariates), revealed that progression to daily cannabis use was associated with age at onset.[14] Fifth, aside from studies linking cannabis use and psychotic disorders, an increasing body of research suggests a potential association between cannabis use and schizotypal symptoms, or psychosis-proneness, in the general population.[15,16]
Several lines of evidence support the potential biologic plausibility of these links between cannabis use and psychosis. First, exogenous (eg, Δ-9-tetrahydrocannabinol) and endogenous cannabinoids (eg, anandamide) exert their effects (such as modulating the release of neurotransmitters including dopamine and glutamate) by interactions with specific cannabinoid (CB1) receptors that are distributed in brain regions implicated in schizophrenia. Second, several studies have shown an increased CB1 receptor density in brain regions of interest in schizophrenia, including the dorsolateral prefrontal cortex and the anterior cingulate cortex.[17,18] Third, other studies report elevated levels of endogenous cannabinoids in the blood and cerebrospinal fluid of patients with schizophrenia.[19-21] Fourth, acute, controlled administration of Δ-9-tetrahydrocannabinol causes both patients and controls to experience transient increases in cognitive impairments and schizophrenia-like positive and negative symptoms.[22] In summarizing these and many other findings, Fernandez-Espejo and colleagues[23] have suggested that the endocannabinoid system is altered in schizophrenia and that dysregulation of this system, perhaps induced by exogenous cannabis, can interact with neurotransmitter systems in a way so that a "cannabinoid hypothesis" can be integrated with other neurobiologic hypotheses (eg, those involving dopamine and glutamate).
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http://www.medscape.com/viewarticle/717957
Early Marijuana Use Heightens Psychosis Risk in Young Adults
...I could have told them that for free...so could anybody else who’s ever been around long term stoners.
personal experience with this, it is a terrible way to lose a child, like falling off a cliff in slow motion
It’s also linked to climate change and going to hell in a hand-basket. Oh please. Make it stop, make it stop. snicker.
So let’s legalize it!
Then it can be mass marketed to retail stores and advertised on MTV!
But...but...but...
Marijuana is less harmful than cigarettes!!! That’s what we’ve always been told. It causes less harm than alcohol. I saw it in the Main Stream Media, so you know it must be so.
Golly, Daddy was right all along.
Is it that marijuana causes psychosis or that people who have a psychotic condition tend to be drawn to marijuana?
“Evidence Accumulates for Links Between Marijuana and Psychosis”
“Evidence accumulates” eh.
I’m in head shakin’ awe.
I saw this with a number of kids growing up and it usually hit in their 20s. Those kids already had problems as kids and were lured to drugs (to feel good and fit in) and it seemed to push them over the edge, leaving full blown schizophrenia. (which is very expensive) But it's impossible to prove, except to show statistical correlations.
The gov’t won’t let anyone test MJ, lest they find out it has some valid medical uses, so how can they determine if it has negative consequences like schizophrenia?
In hushed tones, apparently.
But if links between a substance and mental illness are cause for jailtime, then let's lock up the alcohol drinkers and cigarette smokers too.
Alcohol: Psychological Consequences of Chronic Abuse
http://www.bookrags.com/research/alcohol-psychological-consequences—dat-01/
Everything that affects your brain...well...affects your brain. I’m sure, as with anything, moderation minimizes or negates the effect.
The only good news is it is reversable... coming from a former pothead. I smoked it multiple times every day for about 2 years. It took a few years to really be thinking clearly again once I stopped. While the drug is victimless and the stoner is harmless, unless s/he gets behind the wheel, those who say one can use the drug with no negative side effects are purly in denial. I support legalizing it only because I have a libertarian side and I think it could be taxed and it wastes prison space, but I will personally never get into the stuff again as all it does is assist in wasting time and productivity.
Studies of this sort remind me of a comic I saw once.
Two police officers are walking down a sidewalk, and one says to the other, “I smoked marijuana once. It made me want to hurt and kill.”
Many, many scientific studies show correlations between x and y. Few ever show causation. Many scientists make the mistake of interpretation those studies according to the flawed belief that correlation = causation.
Drinking sodas makes kids fat.
Smoking marijuana makes people psychotic.
In both cases, the correlations are probably real. But the correct interpretation is that an underlying mechanism is responsible for both, not that one causes the the other.
I would be inclined to believe that fat kids drink lots of soda because of a pattern of behavior that leads to obesity. Because they have developed the behavior, their brains lead them to consume high calorie, low nutrient foods. (And this is a biological urge, once the obesity has developed—treating it takes more than just teaching them proper eating.)
I would be inclined to believe that marijuana smokers develop psychosis because of an underlying brain disorder that leads to psychosis. Because their brains are already somewhat off-balance in the neurotransmitter department, they are prone to using neurotransmitter affecting substances.
Good news.
In very high risk people (ages 13 to 25) 4 fish oil capsules a day for 12 weeks lowered the risk of full-blown psychosis by ~80% compared to the placebo group.
Benefits were sustained after patients stopped taking the fish oil.
Amminger GP, Schafer MR, Papageorgiou K, et al.
Long-chain omega-3 fatty acids for indicated prevention of psychotic disorders
Archives of General Psychiatry, 2010;67: 146-154
http://archpsyc.ama-assn.org/cgi/content/abstract/67/2/146