Cannabis' Effects on the Brain

[biohacker]

It's a shame, because such ridiculous THC percentages aren't even needed if you aren't abusing Cannabis to the point of building an insane tolerance.

So very true! This is why i'm hunting and stockpiling outdoor grown strains that have more moderate THC and have been sun kissed. Sun=life! Fuck fake blue wave high intensity manmade lights! I feel it's the more hardcore high THC hydroponic strains that mess us up, same with concentrates. The rates of CHS have skyrocketed since dabbing became all the rage.

Let's get back to nature!

 

[herbivore21]

This is true, but it should be able to make up for the hippocampus volume decrease.

The study we are talking about does not suggest that the hippocampus is overall smaller after cannabis use than before. It only speaks about 'changes' in a non-directional sense most of the time, also one claim of reduced activation of this brain region was observed in certain studies (which did not consider CBD containing cultivars IIRC). The reduced activation of the hippocampus in those studies does not equal reduced volume/mass of this brain region, which was not claimed in this study. The only reference to hippocampus volume described no significant difference on this measure in another study cited:

"In Cousijn et al (2012), volume reduction in the amygdala and the hippocampus does not differ significantly between regular cannabis users and controls but still correlates with the amount of cannabis used and the severity of cannabis dependence, respectively."

When a difference in research is described as 'not significant', that generally means that the difference in measures did not meet statistical thresholds to be considered a 'real difference'; usually because the size of the difference measured was no greater than what may be expected to happen purely by chance when you consider enough different people in a population.

It's a shame, because such ridiculous THC percentages aren't even needed if you aren't abusing Cannabis to the point of building an insane tolerance.

I'd be very careful about making sweeping claims like this bro. Maybe you don't need high THC doses. Maybe I don't need high doses of THC for most of my needs (MAJOR EXCEPTION: Insomnia requires higher doses of THC for me than everything else I medicate for - where like you I tend to go for lower THC levels and more terpenes in my extracts). Doesn't mean that others might not have genuine medical need for this. We don't all have the same neurology and biology, nor do we all have the same medical symptoms which may benefit from cannabis use.

So very true! This is why i'm hunting and stockpiling outdoor grown strains that have more moderate THC and have been sun kissed. Sun=life! Fuck fake blue wave high intensity manmade lights! I feel it's the more hardcore high THC hydroponic strains that mess us up, same with concentrates. The rates of CHS have skyrocketed since dabbing became all the rage.

Let's get back to nature!

I've had wonderful meds from outdoor and indoor grown material man. One is not always going to be better than the other. High CBD, low THC chemovars can be bred in hydroponic scenarios too!

Some of the very best cannabis that I have ever had has been outdoor grown, but some that was equally wonderful was indoor grown. There's a lot more to it. More important to me is the chemotype of the variety being grown, the hygiene and cleanliness of the space and any additives/chemicals used and the extent to which resin is allowed to mature before harvest.

Also man I've never found myself 'messed up' by concentrate use, and as you know I've used only concentrates for a very long time now, in both large, and these days usually lesser quantities. There are many more relevant variables than how much THC is there involved in whether concentrates are going to fuck you up in some way or other. Concentrates can be less harmful than flowers when done the right way.

I do agree that some definitely go overboard with concentrates, like weedtubers doing 1g dabs (TBH, they aren't necessarily doing huge damage to themselves as they waste most of the vapor and never inhale the bulk of it on these big dabs to begin with lol).

I do in one sense agree with getting back to nature by my advocacy for whole resin gland medicines (full melt hashes) though. These IME are an easy way to keep your THC levels lower too, since full melt tends to have less THC/THCA than solvent extracts and rosins.

 

[Alexis]

Alexis, really it's not that much when you think about it, 1/2gram in morning, 1/2 gram early afternoon 1/2 gram dinner, and 1/2 gram evening. A 1/2 gram isn't much IMO, and can basically be two .25 hits,.... perhaps it's because I have massive 7.5+Litre swimmers lungs? Apparently my lung volume is so massive I needed to have TWO chest x-rays because they wouldn't fit on one slide. I have always been an athlete since I was 20 years old, and I also attribute it to my bong usage in university! lol. I know some people are lightweights, but you really have to consider genetics, body composition, etc. For instance, my girl at 5'8 125lbs never used cannabis ever until she was like 33 i think, and she can't vape above 160c, micro doses, and can get lit really easily. I'm 6'3, 185-195 range, single digit body fat, and a very long 20 year history of on/off usage, the last 10 chronic. Because of stress, shift work, etc. I really depended on cannabis to be able to survive, since there was no way I could thrive. This resulted in an increase in tolerance, however it's more the VAS that was my issue.

I became (and still am) addicted to vaporizers and toys related. I have the financial freedom to basically do whatever I want since i'm not married and don't have kids, although it came at a price of my health (both physical but especially mental)....i literally destroyed my brain from long term chronic stress and sleep deprivation. I love vaporizer technology, but you need to feed those toys, and when you have access to the most amazing cannabis strains that can be mailed to my door, it's easy to play.

This is my current issue as well....I want to buy the Herbo Ti, Solo 2, Twax Flowerpot, Hexnail, etc but in order to appreciate and test/play with those devices, you need to feed them. What's the fun in just one or two little sessions, only to have to stop and just stare at your toys? lol I know you are in a completely different position, but you put much time into researching vapes, etc. Some people would ask us how it's possible to spend so much time on FC.... it's all how you look at things and the person's particular situation and circumstances.

With that said, I think it's narrow minded to just look at dosage on a weight scale. 2 grams of shit weed per day vs 2 grams of high thc hydroponic? What about your own personal tolerance level? I know people ( @lwien - may actually be interested in this thread, and a good contributor due to his age and history, as well as he's a runner), he uses micro dosing only in the evening and will go into full withdrawal without. So to HIS brain, .1g/night may be the same as 2g to MY brain.

How long do you hold your hits? What about nutrition and omega's? Set and setting? There are SO many variables, you just can't go based on a weight scale. And then there are edibles.... those can blow your tolerance through the roof....been there. So when that happens, you can vape as much as you want and it doesn't really matter.

I look forward to getting back to a more healthy relationship, but i'm pretty certain if my withdrawal is this easy now, and I regain the ability to sleep somewhat decently, I won't be too concerned about my excessive usage again, unless I get bad side effects (tells me to cut back or take a break again) or have financial issues.

It's so weird though Alexis, our experiences are opposite as you didn't imbibe in as much weed as me, however i've basically never really touched any other drugs in my life, and from your experience, i'm happy I became dependent on weed instead of all the chemical drugs. I was smart enough to avoid them, although fell prey to alcohol until my late 20's, but had zero issues quitting it. I simply cannot become an alcoholic even if I tried, but cannabis on the other hand..... probably because I also know how damaging alcohol is to your health, but confident that cannabis is relatively mild.

Furthermore, vaporizing vs smoking is a huge difference....my first half of cannabis use (10 years on off) was all bong combustion,...it was awful, i'd have a chronic nagging cough constantly, horrible eye bags, and it just was so unhealthy. Vaping on the other hand, zero lung issues (some hacks for the first week or so but now perfect), eye bags are getting way better (probably from more REM and not going to bed high), but I feel sometimes that vaping gets way more cannabinoids to the dome, and could negatively affect the brain differently than smoking it.

Just more food for thought for discussion..and apologies as I just barfed this out from my head and did zero proofreading lol

Thanks for thoughts and ideas. There are certainly a lot of variables involved. And we are all very different physiologically.
I actually believe may hallucinogenic use has made much more sensitive to weed.
And the Lyme Disease is a very big part of it. It is basically to do with the nervous system, that determines the nature and intensity of reactions.
I must do better to keep this in mind.
Saying that, I do believe there are very many people without these issues that would never be able to reach your tolearance for vaping weed.

And it could also be a factor when you are vaping such high strength strains, causing your brain and body to desensitise you to a greater extent.
I also need 2 chest x rays for XL lungs!!!
I can take huge, long hits. I have super technique. Because my weed supply has always been rationed, or cherished, I usually always hold my hits in for at least 5 seconds, maybe 10 often.

If conserving weed was not an issue, and without any allergies, and I was vapong for sheer "fun", then I would surely just vape more and exhale sooner.
There is often disagreement whether hollding in vapor for more than a few seconds gives a stronger effect.
Many deny it. Personally I have no doubt it increases the effects. Whenever I stop holding my hits, I start going through so much more weed, without getting as stoned.
So I dont do it that often. If weed supply was unlimited, I would just vape more amd exhale sooner.

I used to be 6 foot 2. Now Im under 6 foot by an inch or 2. Before I got ill I was really big and muscular, just from working and being busy. I never did any sports or training, but lots af activity, running, and dancing.
I was really fit. That all changed. I am very underweight and obviously highly fatigued. The more ill I am the lower my tolerance for vapor.

Also please always bare in mind that my mental function is heavily compromised by my condition. I talk an awful lot of crap, cant see "wood for trees", so please take with pinch of salt and sift rubbish. I often feel I should not really bd communicating at all, but it is really an escapist coping mechanism.

That's awsome you are feeling increasingly positive about your weed usage and coping with withdrawals in the future. I really hope you can manage until your testing and get a good result, and be able to vape again in a much better physical and mental place.
I senss you have sort of accepted the donsides of weed use as being something you can see youself living with, with a few tweaks of course.


@EverythingsHazy , I appreaciate you sensitivity bro and your open, rational thinking without a touch of arrogance or righteousness.
The CBD relevance to cannabis' effects on the brain and personality is hugely underestimated.

The ratios have been altered so far from nature's original design, and there is very strong evidence that this imbalancd plays a large part in modern cannabis related shizo-affective disorders.

Heavy weed users should really ideally be taking CBD oil, especially those prone to paranoia and delusion. It may also mitigate some adverse physical effects on the brain, "as you go along".

Also, I dont know if this thinking is valid, but very many non cannabis users are taking cbd oil legallly now for a wide range of conditions with life changing benefits. Cbd will be significantly more therapeutic when thc is also taken, for the full synergistic effect.

So in theory, moderate use of quality clean cannabis will compliment CBD oil supplementation.

On this topic of cannabis' effects on the brain, as a precautionary and protective measure, heavy cannabis users REALLY SHOULD try and take cbd supplements alongside.

It is very expensive though, which is a great shame. Big business in a highly competitive market, certainly here in the UK.

Of course, as Biohacker has alluded, one can simply use high CBD strains. But oral supplementation may be a simpler and more effective measure?

 

[C No Ego]

C No Ego said:

"Exactly! usually adding cannabinoids into the system shows immediate effects and what needs up-regulating or down-regulating... but generally people with digestive issues are low in endocannabinoids as the ability to digest food from a homeostasis standpoint is compromised from lack of endocannabinoids... people with excess energy generally have excessive endocannabinoids and could use down regulation... only a couple of medical schools are teaching this at this point and it is very new discoveries scientifically speaking... direct experience has been occurring since the monks started cultivating cannabis strains in the mountains"

I really want to believe this because it's an angle I have never considered before. However, I just don't understand how this is possible. What immediate effects? I have zero digestive issues but feel that the constant bombardment of phytocannabinoids has down regulated my endogenous production of anandamine, and thus resulting in a depleted endocannabinoid system when I don't intake the phytos? It's as if the exogenous phytocannabinoids disrupts homeostasis?

For those with excess energy (i'm bipolar so I know what excess means! lol), wouldn't THC have more of an effect to quell it? It wouldn't necessarily mean that they have excessive cannabinoids?

It just seems quite conjecture, if I even understand correctly, so would love some references or information that I could research up on to get on the same level.

I'm presently on a protracted break, after using for 20 years so this topic really intrigues me.



Again i'd love to see the research, as combustion's deleterious effects on the pulmonary system certainly wreck havoc, even if it doesn't cause cancer (protection by cannabis).

it has to do with each particular cannabinoid and effects from that molecular shape or form of mass... and all the other sub compounds in the plant that have synergistic results.
I am speaking mostly of microdosing to find results ( immediate results) and cannot say anything of someone who for example smoked 2 grams a day for twenty years and what their endocannabinoid system is like after all those years... plus were they smoking cbd, thc, and or the thousands of combinations of molecules depending on where it's grown, soil, nutes, etc...
yes, you can downregulate the endocannabinoid system with external cannabinoids.
we know that the duration of effects from single use correlates with the bodies response at that moment where phytocannabinoids take over endogenous cannabinoids in the ECS system... after effects wear off from the phytos the ECS will regain it's balance and go back to synthesizing it's own cannabinoids from the arachidonic acid, depending on how much of that you provide for yourself from diet and lipid fat consumption...
each person will be different in what they would need in terms of those molecules...
Personally. I believe that if grown with love you can ask the plant to provide you with what is needed for homeostasis of your biology with cannabis having the ability to organically grow it's own protective compounds for it's own homeostasis, imprinting your intent ( vibe) on the plants structure while growing will produce compounds in favor of your survival too! this one plant can hold in it's structure so many differing molecular compounds ( more than any other plant on earth) and the surroundings the plant grows in matters!

please check out this guys info-
Dr Bob Melamede
http://www.drbobmelamede.com/home.html
I've gained interest from guys like him and others who are pioneering this type of information..
I'll get back yo more later.. Peace

Why is there proof of lower brain volumes in Cannabis users, in regions of the brain that have higher densities for cannabinoids? That's what I'm wondering. It just so happens that some of these areas have a lot to do with pleasure/reward processing, and motivation.

Constantly bombarding those areas with cannabinoids, if it lowers their volume, possibly due to effects on synaptic pruning, can't be good for long term mental health.

the underground thc only cannabis has caused a sway to much to one side leaving cbd in the dust... that can cause mental problems

 

[biohacker]

Thanks C No Ego, really appreciate the follow up as well as reference, I will definitely do some more research, wow this shit goes deep! So if I understand correctly, it's more the person who does not imbibe or doesn't imbibe frequently, that we can see with micro dosing what a "response" of that use is? Interesting, and makes sense as receptors are the main factor here I do think. Apparently first time users don't feel medicated because they haven't built up more receptors. Dr. Sulak is very interesting as well, and has much to discuss regarding receptors, tolerance, sensitivity, etc. Fascinating stuff! Thank you!

Completely agree about the thc bred strains causing the most mental problems....i'm sure it has been a major factor in my own, which i'm presently biohacking to be able to get the most out of this life.

I'm also now appreciating that diet has an even more profound impact on all of this brain health than I originally thought.

 

[I'm Ron Burgundy?]

So very true! This is why i'm hunting and stockpiling outdoor grown strains that have more moderate THC and have been sun kissed. Sun=life! Fuck fake blue wave high intensity manmade lights! I feel it's the more hardcore high THC hydroponic strains that mess us up, same with concentrates. The rates of CHS have skyrocketed since dabbing became all the rage.

Let's get back to nature!

I very much agree with sunlight being the ultimate source for growing cannabis. There are terps and flavor profiles you just won't get with indoor.

All the bagseed I've grown outside has always had tremendous flavor. The whole entourage effect I guess.

As far as the effects on the brain well.... it does my brain good lol.

 

[biohacker]

I very much agree with sunlight being the ultimate source for growing cannabis. There are terps and flavor profiles you just won't get with indoor.

Isn't that the truth! The strains i've recently acquired are SO fruity smelling!

The stockpile continues....found some more organics!

 

[Alexis]

Interesting what you say about first time users. This goes back to hippy folklore how you dont get stoned the first time you smoke weed. I always presumed this was a consciousness thing,,where you just had to re-experience it the second time in order to recognise and tap into the experience. With it being instantly familiar

I grew up with hippy fairy tales. My mum told me how the first time they smoked pot, they were convinced it hadnt done anything, but to others it was dead clear they were under the influence, and driving the car at like 10 miles per hour thinking they were going really fast

My own first ever cannabis experience, I chewed up a gram of hash. I had already been taking e's and trips for a year. I remember hiw it knocked me out, and I can see how my behaviour and demeanour looked to my straight friend with me.
I was clearly stoned, knocked out in a disasociative way. I scoffed a load of food, and basically fell asleep.

Next time I saw my older friends who gave me the "blow", they asked me:
"How did you get on with it?"
I said "It didnt do anything! All I did was eat 2 boxes of apple pies and fall asleep!"

They laughed, and said "Sounds to me like you got wrecked!"

I DID get very stoned, but the experience flew over my head!

 

[biohacker]

A body of evidence is now emerging that links endocannabinoid deficiency to a variety of diseases, including migraine, fibromyalgia, irritable bowel syndrome, and even infant colic. As I realized this, I began to wonder: can an individual enhance his/her cannabinoid system by taking supplemental cannabis? Beyond treating symptoms, beyond even curing disease, can cannabis help us prevent disease and promote health by stimulating an ancient system that is hard-wired into all of us?

I now believe the answer is yes. Research has shown that small doses of cannabinoids from cannabis can signal the body to make more endocannabinoids and build more cannabinoid receptors. This may be why many first-time cannabis users don’t feel an effect, but by their second or third time using the herb they have increased cannabinoid sensitivity and are ready to respond. More receptors increase a person’s sensitivity to cannabinoids; smaller doses have larger effects, and the individual has an enhanced baseline of endocannabinoid activity.

My clinical experience has lead me to believe that small, regular doses of cannabis might act as a tonic to our most central physiologic healing system.

-------

Note to self: SMALL DOSES jackass!

 

[Alexis]

Yes I am also subscribed to the NECESSITY of supplementing with cannabinoids for optimal health and balance, and essentially homeostasis.

To me this has to be maybe the most key reason why illuminati and co have strived to take it away from us. All the things that are good for us, first target- get rid of it, second, make it less helpful and more harmful.

Third- a mixture but make sure they profit somehow and maintain control.
I do believe that many sick people with conditions you have mentioned above, who never ingest any form of cannabis, are lacking this "dietary essential" with no idea about it.

But as @C No Ego has gestured, there is a huge variation of the specific cannabinoids and their exact levels and ratios.
Ideally, we each require individually tailored material according to our requirememts at any given time, in order to make cannabis the ultimate medicine. It is the same concept as nutritional balancing, but is curently done totally haphazardly by MJ medical practitioners and patients. Kind of "pot" luck!

I do imagine, one day technology will be advancd enough to determine the precise cannabinoid requirements of the individual, and hopefully, provide exactly that, free of charge of course, in the healthiest, purest manner possible.

Idealist at heart or what?
When I see my homeopath for Vega testing, I have taken samples of different plants we grew. The feedback is very interesting and as always a perfect reflection of my experience with any given substance.

Generally sativas usually show more benefit with little to no downside. Indicas dont suit my fatigue condition very well, but still show some benefit, but with some negative effects as well.

One summer, we grew a pure indica "Holland's Hope". We harvested it too late. All trichomes dark amber. It had a really debilitating effect on me, I didnt like it at all.

When Natasha tested it, she frowned and said "It's actually degenerative".
Which means to me- it takes energy away, which is precisely what it did, compared to the lighter sativas we harvested at the right time.
And that is basically CBN! I dont like it, dizziness, lethargy.

 

[biohacker]

For what it's worth, an Ayurvedic perspective:

The ayurvedic texts declare that a medicine properly used becomes nectar and improperly used becomes poison.

Medical Research on Marijuana (Cannabis)

Current reviews of the medical research literature suggest that daily consumption of cannabis in teens is associated with depression and anxiety and development of schizophrenia. Studies indicate that its use can have an irreversible, long-term effect on the brain. Imaging studies show significant changes in brain function and, with continued use, the appearance of functional “holes” — vast areas of brain matter that are dysfunctional. There is some evidence that regional structural changes are associated with cannabis use patterns as well as measures of psychopathology. The volume of cortical grey matter is progressively reduced in schizophrenia, with larger grey matter volume decreases associated with cannabis use. A current neurophysiological model indicates cannabis-induced schizophrenia is a distortion of normal late-postnatal brain maturation. Adolescent exposure to cannabis transiently disturbs physiological control of the endogenous cannabinoid system over brain function. As a result, THC (the primary active ingredient in cannabis) may adversely affect adolescent experience-dependent maturation of neural wiring within prefrontal cortical areas. Depending on the amount, time and duration of use, this may ultimately lead to the development of psychosis or schizophrenia. Together, these studies highlight the cannabis-related dysfunction of the prefrontal cortex, the central switchboard of executive control and decision-making. Think of the prefrontal cortex as the highest, most powerful value of the “intellect.” As such, and as part of a distributed neural reward system, the prefrontal cortex is responsible for guiding our thinking, emotions and behavior along evolutionary, non-destructive pathways.

Drugs can be used, abused or addictive. Abuse is a behavior that continues to occur in the face of obvious negative consequences because one is uneducated or unaware; however, addiction is a brain disease characterized by impaired behavior control that is evident to others while the individual affected becomes increasingly distorted and dysfunctional in their thinking, feelings and behaviors. Gambling may be exciting, but you end up in financial and family ruin most of the time. THC disrupts prefrontal cortical function communication with other brain regions. If the prefrontal cortex goes offline, then our ability to monitor and respond properly to negative outcomes (think of a variety of brain and behavioral problems) is reduced and eventually lost. One is left with the addiction and increasing difficulties in life. Recent research suggests chronic interference with the endocannabinoid system by marijuana use may facilitate drug dependence and impair the body’s natural homeostatic balancing mechanisms.

The Biochemistry of Cannabis

The primary active ingredient of cannabis is Tetrahydrocannabinol (THC, delta-9-tetrahydrocannabinol). This compound is the main psychoactive component of cannabis because it mimics the actions of naturally-occurring chemicals in the nervous and immune systems that are called endocannabinoids. THC does this by activating cannabinoid receptors. The endocannabinoid system is involved in a variety of critical brain processes including appetite, pain sensation, mood, and memory. These same receptors play a major role in drug abuse as well. THC alters the activity of central reward pathways in a manner that is consistent with other abused drugs. Most users have no understanding that current marijuana cultivation is yielding THC levels that are consistently 5-20 times more potent than those found in the 1960s and 70s. Thus, each inhalation can lead to considerably more impact subjectively that must be associated with larger, more disruptive levels in the brain.

The endocannabinoid system (ECS) is a group neuromodulatory lipids (fats) and receptors. In recent years, this system has emerged as an important regulator of a wide variety of functions in the central nervous system. It appears to modulate widespread neuronal activities and is responsible for the fine-tuned functioning of the central nervous system, aimed at ensuring balanced functioning ─ homeostatic conditions ─ of the brain. Importantly, given its biochemical and physiological features, the ECS appears to act “on demand.” Thus, the system intervenes to maintain the body’s balance only when and where its activity is needed. The key words here are “on demand!”

The human body makes its own cannabinoids as a means of maintaining homeostasis. The whole system, like everything in the human body, is very delicate and complicated. Unfortunately, marijuana is like a “sledge hammer” ─ a very potent, crudely-introduced influence that overloads the brain and bodily regulation. Use of marijuana distorts the intelligent functioning of the brain’s endocannabinoid system. Artificial ingestion of cannabinoids in the form of cannabis throws the body out of balance, interfering with an otherwise precise mechanism. Though marijuana may provide some short-term subjective high, its use may induce short- as well as long-term disturbance of the normal equilibrium of the ECS system and may contribute to a variety of different unwanted symptoms and diseases. Research also suggests that marijuana does qualify as a “gateway” drug, increasing the likelihood that the casual user will engage in drugs that are both stronger and more destructive as the disease of addiction progresses — biologically, psychologically, socially and spiritually.

The Ayurvedic Perspective

One of the founders of Ayurveda, Dhanavantari, developed a medical lexicon of the qualities and effects of herbs, including cannabis. According to this description, cannabis is sharp, heating and light in its quality. Being sharp and “heating,” it increases humoral bile and removes humoral phlegm. It also stimulates delusions, slows speech, and raises the heat of the digestive fire. Note that these ancient symptoms are all so common to the cannabis user of today: hallucinations, distortion of speech and cognition, and the “munchies.”

In Ayurveda, cannabis used as a recreational drug is considered toxic to the mind and body. It has been used for thousands of years as a component in various preparations, but not as an isolated herb. In Ayurveda, it is not considered an important herb. However, like any botanical, this herb can have some good effects, depending on what you are using it to do. When properly prepared in a synergistic formula and used in minute quantities under the care and direction of an expert, it can aid digestion. The use of cannabis is always in a synergy with other herbs and spices and never by itself. (No such products are sold in the United States.)

People ask why it would be that an herb that has medical use in some cases can cause negative side effects in other cases. According to the Ayurvedic texts, medicine properly used becomes nectar and improperly used become poison. When marijuana is used in ways not prescribed or intended (for example, in doses and for periods of time not prescribed), it can cause a host of imbalances and side effects, including stimulating delusions and slowing speech.

“Recreational use of marijuana creates ama,” says Jadgish N. Vaidya, Director of Maharishi Ayurvedic Programs at Lancaster Health Center in Lancaster, Massachusetts. “It impairs digestion and intellect, it upsets hormonal balances, and it can be addictive, in the traditional view of Ayurveda.” The classically-trained Vaidya, or Ayurvedic expert, adds, “It is not a path to enlightenment. Enlightenment is the moment-to-moment awareness of totality; the full inner and full outer value of awareness. Not the loss of awareness.”

 

[EverythingsHazy]

Anyone else have any scientific studies to share in regards to brain volume or any other brain related effects?

@EverythingsHazy , I appreaciate you sensitivity bro and your open, rational thinking without a touch of arrogance or righteousness.
The CBD relevance to cannabis' effects on the brain and personality is hugely underestimated.

The ratios have been altered so far from nature's original design, and there is very strong evidence that this imbalancd plays a large part in modern cannabis related shizo-affective disorders.

Heavy weed users should really ideally be taking CBD oil, especially those prone to paranoia and delusion. It may also mitigate some adverse physical effects on the brain, "as you go along".

Also, I dont know if this thinking is valid, but very many non cannabis users are taking cbd oil legallly now for a wide range of conditions with life changing benefits. Cbd will be significantly more therapeutic when thc is also taken, for the full synergistic effect.

So in theory, moderate use of quality clean cannabis will compliment CBD oil supplementation.

On this topic of cannabis' effects on the brain, as a precautionary and protective measure, heavy cannabis users REALLY SHOULD try and take cbd supplements alongside.

It is very expensive though, which is a great shame. Big business in a highly competitive market, certainly here in the UK.

Of course, as Biohacker has alluded, one can simply use high CBD strains. But oral supplementation may be a simpler and more effective measure?

Thanks @Alexis. It seems like we've gotten a good, albeit small, group of members who can discuss this stuff without getting defensive/offensive.

 

[biohacker]

FYI Below are some science citations that may be of interest to readers. I have no read these, nor endorse them. Just more info to use to think critically.

…cannabis, like any drug, may have some health benefits (for example, under proper professional care, the therapeutic treatment of chronic pain and some neurological disorders:

http://www.msrc.co.uk/index.cfm/fuseaction/show/pageid/1815/

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1503422/

Cannabis use during adolescence interferes with proper brain development, may cause anxiety disorders, and increases the risk of developing psychotic disorders later in life. Psychosis:

http://www.drugabuse.gov/publicatio...ere-link-between-marijuana-use-mental-illness

http://aje.oxfordjournals.org/content/156/4/319.full

The past forty years of research on cannabis and its active compounds clearly indicates that cannabis use is not without risks for brain dysfunction. Psychosis:

http://www.drugabuse.gov/publicatio...ere-link-between-marijuana-use-mental-illness

Current reviews of the medical research literature suggest that daily consumption of cannabis in teens is associated with depression and anxiety and development of schizophrenia. Studies indicate that its use can have an irreversible, long-term effect on the brain. Imaging studies show significant changes in brain function and, with continued use, the appearance of functional “holes” — vast areas of brain matter that are dysfunctional.

http://www.time.com/time/health/article/0,8599,2005559,00.html

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2900481/

http://www.zmescience.com/medicine/genetic/researchers-find-marijuana-spreads-and-prolongs-pain/

There is some evidence that regional structural changes are associated with cannabis use patterns as well as measures of psychopathology. The volume of cortical grey matter is progressively reduced in schizophrenia, with larger grey matter volume decreases associated with cannabis use.

http://www.ncbi.nlm.nih.gov/pubmed/21466751

A current neurophysiological model indicates cannabis-induced schizophrenia is a distortion of normal late-postnatal brain maturation. Adolescent exposure to cannabis transiently disturbs physiological control of the endogenous cannabinoid system over brain function. As a result, THC (the primary active ingredient in cannabis) may adversely affect adolescent experience-dependent maturation of neural wiring within prefrontal cortical areas. Depending on the amount, time and duration of use, this may ultimately lead to the development of psychosis or schizophrenia.

http://www.ncbi.nlm.nih.gov/pubmed/20624444

Together, these studies highlight the cannabis-related dysfunction of the prefrontal cortex, the central switchboard of executive control and decision-making.

http://www.sciencedirect.com/science/article/pii/S0028390807001980

THC disrupts prefrontal cortical function communication with other brain regions.

http://www.cogsci.ucsd.edu/~pineda/COGS260/marijuana/Cannabinoids and PFCtx.pdf

http://www.ncbi.nlm.nih.gov/pubmed/16163518

http://www.druglibrary.org/crl/behavior/jentsch-01.pdf

Recent research suggests chronic interference with the endocannabinoid system by marijuana use may facilitate drug dependence and impair the body’s natural homeostatic balancing mechanisms. Addiction:

http://www.drugabuse.gov/publications/research-reports/marijuana-abuse/marijuana-addictive

THC alters the activity of central reward pathways in a manner that is consistent with other abused drugs. Most users have no understanding that current marijuana cultivation is yielding THC levels that are consistently 5-20 times more potent than those found in the 1960s and 70s. Thus, each inhalation can lead to considerably more impact subjectively that must be associated with larger, more disruptive levels in the brain.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1575338/

Use of marijuana distorts the intelligent functioning of the brain’s endocannabinoid system. …its use may induce short- as well as long-term disturbance of the normal equilibrium of the ECS system and may contribute to a variety of different unwanted symptoms and diseases.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3052937/

http://www.calgarycmmc.com/cognativeeffects.htm#733759594

(numerous citations/studies)

Research also suggests that marijuana does qualify as a “gateway” drug, increasing the likelihood that the casual user will engage in drugs that are both stronger and more destructive as the disease of addiction progresses — biologically, psychologically, socially and spiritually.

http://www.columbia.edu/cu/record/archives/vol20/vol20_iss10/record2010.24.html

http://www.marijuana-detox.com/news-left.htm?aid=49

Cannabis smoke contains 400 compounds including 60 cannabinoids. However, because of its lower combustibility it contains 50% more carcinogenic polycyclic aromatic hydrocarbons including naphthalene, benzanthracene, and benzopyrene, than tobacco smoke. A recent Canadian study found that marijuana smoke caused significantly more damage to cells and DNA than tobacco smoke.

http://www.mrc.ac.uk/Newspublications/News/MRC006135

http://www.sciencedaily.com/releases/2009/06/090615095940.htm

http://www.ecnis.org/index.php?option=com_content&task=view&id=1130&Itemid=144

http://www.drugfree.org/drug-guide/marijuana

There is now convincing evidence that, due to this toxicity of cannabis, regular usage damages DNA, leaving the possibility of the initiation of cancer development.

http://www.decp.org/documents/index.cfm?fa=document&document_type_id=3&document_id=450&subtype_id=

http://www.sciencedaily.com/releases/2009/08/090805110741.htm

Research indicates that loss of mental stability is one significant side effect from recreational marijuana use.

http://www.beckleyfoundation.org/pdf/hall_HealthAndPsychologicalEffects_2001.pdf

http://cyber.law.harvard.edu/evidence99/marijuana/Health_1.html

Additional unmentioned citations:

Attention. memory and learning:

http://www.drugabuse.gov/publicatio...-marijuana-use-affect-school-work-social-life

Driving:

http://www.drugabuse.gov/publicatio...juana-abuse/does-marijuana-use-affect-driving

Fetal Development:

http://www.drugabuse.gov/publicatio.../can-marijuana-use-during-pregnancy-harm-baby

NTY on addiction and MJ:

http://www.nytimes.com/2009/07/19/fashion/19pot.html?pagewanted=all

 

[archangelz001]

@biohacker - you should at least click on your links before posting to be sure they are still active. Many you posted above are not...

the very first one is a dead link: http://www.msrc.co.uk/index.cfm/fuseaction/show/pageid/1815/

This one is dead too:
"There is now convincing evidence that, due to this toxicity of cannabis, regular usage damages DNA, leaving the possibility of the initiation of cancer development."
http://www.decp.org/documents/index.cfm?fa=document&document_type_id=3&document_id=450&subtype_id=
And why would anyone go to the International Chiefs of Police website for balanced data about cannabis use and it's effects??? And regular use damages DNA????

Here is a pdf of the actual study: http://www.ukcia.org/research/ComparisonOfSmoke.pdf

and here is a summary statement about it https://f1000.com/prime/1164339:
"Since prior studies have not tended to identify an excess of lung cancer in marijuana smokers, these observations suggest the need for larger and more detailed studies in both lab animals and humans to determine whether potentially genoprotective marijuana constituents (e.g. THC) diminish the mutagenicity of DNA-damaging species formed during marijuana combustion."
Tashkent's 30 year longitudinal study at UCLA of marijuana smokers showed that they actually have less likelihood of lung cancer development than the general population, with the assumption being that THC and other cannabinoids have a protective effect on the lungs.

This one's dead too:
http://www.calgarycmmc.com/cognativeeffects.htm#733759594

this one is completely laughable: http://www.drugfree.org/drug-guide/marijuana

I hate to be critical but it looks like you got many of these links from "Drug Warrior" sites that spread the worst kind of "science" - unsupported conclusions based on associations rather than provable cause/effect

 

[biohacker]

Apologies, all I did was google "ayurveda cannabis" and it was the first link that came up. There are some good links to valid scientific studies as well you neglected to mention. Far from "drug warrior".

https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=ayurveda+cannabis

This is the second link, appears to only be a year old, but offers some perspective.

http://everydayayurveda.org/ayurvedic-cannabis/

more studies, the last one about CBD is very interesting indeed!!!

An Evidence Based Review of Acute and Long-Term Effects of Cannabis Use on Executive Cognitive Functions

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3037578/

http://s3.amazonaws.com/academia.ed...=Effects_of_frequent_marijuana_use_on_bra.pdf

Effects of Chronic, Heavy Cannabis Use on Executive Functions

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3106308/

Long lasting effects of chronic heavy cannabis abuse.

https://www.ncbi.nlm.nih.gov/pubmed/28314070

Grey Matter Changes Associated with Heavy Cannabis Use: A Longitudinal sMRI Study.


https://www.ncbi.nlm.nih.gov/pubmed/27224247

Hippocampal harms, protection and recovery following regular cannabis use.

https://www.ncbi.nlm.nih.gov/pubmed/26756903

Pubmed is great...I just input long term cannabis brain.

 

[archangelz001]

It's fine to be looking for studies that present the dangers of cannabis consumption, but you have to get your bullshit detector out when reading the conclusions from some of the researchers who have their studies funded by NIDA, DEA, NIH. The US Government is not looking to allow studies which present contrary evidence to the currently still negative narrative about the dangers of cannabis.

I see that your original list is from the Maharishi Ayurveda site - a site for selling herbal preparations from the Transcendental Meditation organization (http://www.mapi.com/blog/the-ayurvedic-view-of-marijuana.html). I'm not sure why you would go there if you are looking for balance. I was a regular TMer from 1972 through the early 2000's and still meditate irregularly) and am very familiar with the anti-cannabis attitude of TM. Ayurvedic medicine is a very old Indian construct that seeks to explain health and consciousness through ideas of metabolic types "pitta", "vaka" and "kaffa". This just doesn't translate very well with western evidence-based medicine (FYI, I am a retired RN with 40 years of experience working in acute-care hospital facilities)

Here we have a reference to that same study that claims cannabis smoke is more deadly than tobacco smoke. I have a bridge in Brooklyn to sell you if you believe that. http://www.mapi.com/blog/the-ayurvedic-view-of-marijuana.html

"Cannabis smoke contains 400 compounds including 60 cannabinoids. However, because of its lower combustibility, it contains 50% more carcinogenic polycyclic aromatic hydrocarbons, including naphthalene, benzanthracene, and benzopyrene, than tobacco smoke. A recent Canadian study found that marijuana smoke caused significantly more damage to cells and DNA than tobacco smoke. There is now convincing evidence that, due to this toxicity of cannabis, regular usage damages DNA, leaving the possibility of the initiation of cancer development."​

The article on this site - http://everydayayurveda.org/ayurvedic-cannabis/ - has some ridiculous claims that are unsupported by any objective evidence:

"A Materia Medica of Indian herbalism published in 1941 does warn of the long-term effects of cannabis use. It is noted that it will lead to:

• Indigestion
• Tissue depletion
• Melancholia and impotence"

bad link to a non-existent google doc:
http://s3.amazonaws.com/academia.ed...=Effects_of_frequent_marijuana_use_on_bra.pdf

Here are links to studies that present a balanced approach to understanding the effects of cannabis:
https://www.scientificamerican.com/article/how-medical-marijuana-s-chemicals-may-protect-cells/

Watch Dr. Dustin Sulak's 3 videos about Potential Health Benefits of Medical Marijuana:

Cannabis for Chronic Symptoms and Medical Conditions
https://www.cannabisreports.com/cannabis-studies

This is the best list, updated annually, of relevant studies and articles about cannabis -
Granny Storm Crow's complete list of studies:
https://grannystormcrowslist.wordpress.com/the-list/

and specifically regarding the Brain:
https://grannystormcrowslist.wordpr...2015/2010-2016-studies-on-conditions/b/#BRAIN

I hope this is helpful

 

[biohacker]

Thanks archangelz, very helpful....i didn't know some of that.

Ayurvedic medicine is a very old Indian construct that seeks to explain health and consciousness through ideas of metabolic types "pitta", "vaka" and "kaffa". This just doesn't translate very well with western evidence-based medicine (FYI, I am a retired RN with 40 years of experience working in acute-care hospital facilities)

Good, i'm very anti-western evidence based medicine! This approach kills hundreds of thousands of innocent people every year. I have had personal experience with Ayurveda, and it helped me tremendously. Western medicine on the other hand, well many surgeries that I shouldn't of even had, botched surgeries, and alot of pharma shoved down my throat. No thanks.

I've seen it time and time again that combusting weed compared to tobacco does in fact have much more tar, I believe this is fact. However we're on a fuck combustion forum, so let's not even go there.

There can also very much be melancholia, indigestion, tissue and energy depletion and impotence, however again maybe due to combustion's negative affects.

Regardless, this isn't a war about whether cannabis is bad or good for us, we're all on the same side here I do believe if we have an open mind to the pros and cons.

So, i'll stop posting anything unless it relates directly to the LONG TERM effects of cannabis on the brain.

Dr Sulak is amazing! But I take it all with a grain of salt, even all the "pro" studies. Thanks for posting the links!

Personally I think studies are always biased or money/incentive based. Just gotta look at who pays for it all.

 

[archangelz001]

Thanks archangelz, very helpful....i didn't know some of that.

Good, i'm very anti-western evidence based medicine! This approach kills hundreds of thousands of innocent people every year. I have had personal experience with Ayurveda, and it helped me tremendously. Western medicine on the other hand, well many surgeries that I shouldn't of even had, botched surgeries, and alot of pharma shoved down my throat. No thanks.

I've seen it time and time again that combusting weed compared to tobacco does in fact have much more tar, I believe this is fact. However we're on a fuck combustion forum, so let's not even go there.

There can also very much be melancholia, indigestion, tissue and energy depletion and impotence, however again maybe due to combustion's negative affects.

I'm not anti-western medicine. I owe my life to it, from the urgent surgery I had in '98 for colon cancer, to the left shoulder replacement I had done in 2012 and the prostatectomy for prostate cancer I had in 2014. I'm not sure about the "hundreds of thousands" it kills every year. As with anything we have to look at the balance sheet to assess whether it has a negative or positive value. And I think I can say without any hesitation that IMHO it's positive. I find Chinese medicine, and the concept of "chi", more understandable (but of course I'm a practitioner of Chen style TaiJi.) I think that cannabis smoke has more "tar" evidence because it's the plant resin that has all the goodies and we see the residue in our vaporizers ;-) But Tashkent's UCLA study demonstrated that there appears to be a protective mechanism we don't yet understand with THC in cannabis smoke that prevents cancer. I find it irritating and cough inducing, which is why I don't smoke joints or bongs (at least not very often.)

Yes, we can't stick our heads in the sand and ignore the negatives, but the negative narrative has been abused and misused by our government for the past 80 years and more, and those of us who understand and appreciate it's benefits need to stand up in society and come out green.

 

[chris 71]

i had a brain MRI , in i think 2013 , after 30 years of on and off , mostly on lol , chronic cannabis use probably ten years solid use leading up to my MRI . nothing abnormal was mentioned and my doctor said i was all good .
not that the reason for the MRI was anything to do with cannabis use , or in regards to comparing my brain to others in any kind of study , maybe they didnt look hard enough lol . i dont know but it seems that no damage or anything abnormal jumped out to the docs soo .....

 

[biohacker]

Thanks so much for sharing that Chris! And how's your Grasshopper from THC doing?

My psychiatrist told me there is no way to test for mental health that's black and white (adhd, bipolar, etc) but i'm not sure why he wouldn't order an MRI of my brain?

Maybe I should just cross the border and pay for my own?

 

[chris 71]

no prob biohacker , im waiting for my grasshopper to come back from repair . been using my trusty solo as of late , thinking of picking up one of the solo 2s wen they come out .

when my doc sent me for my MRI it was because i was complaining about a kink in my neck , and how when i turned a certain way i would see spots of light when it pinched . not sure why exactly he sent me for a brain MRI when to me the problem was in my neck . i supose it was because of the light spots i was seeing but seemed very clear to me they were related to my neck and spine .

 

[EverythingsHazy]

PART ONE:

Here's some cool info I found while reading some pubmed (pretty legit) articles. I've highlighted what I've interpreted to be positive info in green, and some negative findings in red (Note: I do not have any medical qualifications so don't take my interpretation as fact). Some info was hard to put into either the "positive" or "negative" category, so I just highlighted it based on where I felt it belonged in reference to this thread. I'll do more of these posts, as I read through more PubMed studies.


Study #1: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5068875/

We believe this is the first multimodal MRI investigation of prolonged THC and CBD exposure or abstinence on hippocampal integrity in current and former cannabis users, respectively. We confirmed that hippocampal volume is reduced in long-term cannabis users, and found that this atrophy can be restored following prolonged abstinence. Moreover, we show for the first time that both hippocampal volume and neurochemistry are reduced to the greatest extent in users exposed to THC without CBD. In contrast, current users of cannabis containing CBD, as well as former users, show no structural or neurochemical hippocampal differences compared with controls. These findings are consistent with suggestions that CBD may be neuroprotective, perhaps through its role in synaptic plasticity and/or neurogenesis.23

The findings have implications for how we conceptualise the long-term effects of cannabis use on the human brain. Our findings suggest that not all cannabis users experience adverse brain and behavioural outcomes24, 25 as cannabinoid compounds such as CBD may have a role in minimising harm. Indeed, previous reports have suggested that CBD may ameliorate psychotic and adverse cognitive effects of THC.6, 21, 26, 27, 28 For instance, participants pretreated with CBD experience significantly reduced psychotogenic and anxiogenic effects of THC.26, 27, 28, 29, 30, 31 At a neural level, CBD exerts opposing effects to THC on brain function and connectivity in regions that are high in cannabinoid receptors including the hippocampus.27, 29, 30, 31, 32, 33 Although the relative contribution of THC and CBD to overall brain harm remains unclear, we provide preliminary evidence that these major cannabinoid compounds have a distinct role in hippocampal structural and neurochemical integrity following chronic exposure to cannabis.

The role of CBD in reducing brain and behavioural harms of cannabis warrants consideration when discussing legalisation related to the potency and composition of commercial cannabis. Whether its mandatory inclusion as a public health directive would protect against poor functional outcomes, such as severe mental health problems or cognitive decline among regular cannabis users, remains to be substantiated.

In former users, hippocampal integrity was comparable to controls. This contrasts results from other studies of abstinent former users that have found persistent effects of heavy use on brain function and cognition. In a prospective study of 1037 people from birth to age 38, persistent cannabis exposure (assessed at ages 18, 21, 26, 32 and 38 years) was associated with significant decline in neuropsychological performance. Of note, these cognitive impairments did not show significant improvement following reduction of use or complete abstinence (>1 year cessation in some cases). In the context of our data, these findings suggest that functional deficits may persist in abstinent former users, despite apparent recovery of hippocampal integrity.

Study #2: https://www.ncbi.nlm.nih.gov/pubmed/28314070

CONCLUSIONS:
The existence of hallucinations, delusions, and organic brain dysfunction in heavy cannabis users seems to be associated with cannabinoid levels in hair. The continuation of persistent symptoms 3 months after the discontinuation of cannabis abuse, was a remarkable finding.

SCIENTIFIC SIGNIFICANCE:
We provide evidence that chronic and heavy cannabis abuse results in long-lasting brain dysfunction in all users and in long-lasting schizophrenia-like psychotic symptoms in more than half of all users. These findings suggest a reevaluation of the current classification of cannabis as a "soft narcotic" which erroneously, therefore, is typically considered harmless. (Am J Addict 2017;XX:1-8).

 

[EverythingsHazy]

PART TWO:

Study #3: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4880314/

Abstract
Cannabis is the most frequently used illicit drug worldwide. Cross-sectional neuroimaging studies suggest that chronic cannabis exposure and the development of cannabis use disorders may affect brain morphology. However, cross-sectional studies cannot make a conclusive distinction between cause and consequence and longitudinal neuroimaging studies are lacking. In this prospective study we investigate whether continued cannabis use and higher levels of cannabis exposure in young adults are associated with grey matter reductions. Heavy cannabis users (N = 20, age baseline M = 20.5, SD = 2.1) and non-cannabis using healthy controls (N = 22, age baseline M = 21.6, SD = 2.45) underwent a comprehensive psychological assessment and a T1- structural MRI scan at baseline and 3 years follow-up. Grey matter volumes (orbitofrontal cortex, anterior cingulate cortex, insula, striatum, thalamus, amygdala, hippocampus and cerebellum) were estimated using the software package SPM (VBM-8 module). Continued cannabis use did not have an effect on GM volume change at follow-up. Cross-sectional analyses at baseline and follow-up revealed consistent negative correlations between cannabis related problems and cannabis use (in grams) and regional GM volume of the left hippocampus, amygdala and superior temporal gyrus. These results suggests that small GM volumes in the medial temporal lobe are a risk factor for heavy cannabis use or that the effect of cannabis on GM reductions is limited to adolescence with no further damage of continued use after early adulthood. Long-term prospective studies starting in early adolescence are needed to reach final conclusions.

Discussion
The current 3-year longitudinal study investigated the relation between heavy cannabis use and regional grey matter volume over time. GM volumes in the OFC, ACC, insula, striatum, thalamus, amygdala, hippocampus and cerebellum were prospectively compared between a CB and HC group and related to cannabis use measures within the CB group. In contrast to our hypothesis, there were no differences between the CB and the HC group in GM volume changes. Moreover, changes in weekly cannabis use and cannabis use related problems were not significantly related to changes in GM volumes. Finally, cross-sectional analyses at baseline and follow-up revealed consistent correlations between GM volumes in the left medial temporal lobe (i.e., hippocampus, amygdala, STG) and cannabis related problems and cannabis use (in grams). Our previously reported finding of an inverse relationship of hippocampal volume and amount of use (gram/week) is not significant in the current (smaller) sample. Interestingly, we do find this relationship at follow-up. In addition, our finding of larger cerebellar volumes in cannabis users than controls (found in the larger sample of 33 cannabis users and in the current (sub)sample at baseline is no longer significant at follow-up (for an overview of the findings of our baseline paper and the current paper, see Table A in S1 Table). During typical development, cerebellar volumes decrease over time [37]. Possibly, in cannabis users, this decrease is occurring at a later age, which may explain the group difference observed at baseline but not at follow-up. However, we cannot confirm this hypothesis with only two assessments, and future studies should take this into account.

The lack of significant changes between groups in GM volume over time suggests that cannabis use (>5 years) during late adolescence and early adulthood does not change GM morphology. The cross-sectional negative correlations between medial temporal lobe volumes and the severity of cannabis use suggests that cannabis use related changes in GM were already present before the onset of our study and did not worsen after continued use in adolescence. On the other hand, we cannot rule out that these GM correlations may have been already present before the initiation of cannabis use and may represent a vulnerability factor for heavy use or dependence.

If the cross-sectional relations in temporal brain areas are a direct consequence of (heavy) cannabis use, this means that only those with the most severe patterns of cannabis use will suffer from GM volume reductions but that these GM reductions do not get worse with continued heavy cannabis use after a certain age, i.e. in our sample—with a mean age of 20 years—the maximum volume decreases would have already been reached. This interpretation of our cross-sectional findings is in line with recent conclusions from two reviews [11, 38] suggesting that smaller GM volumes in cannabis users are mostly present in temporal brain areas, but may only be evident in the most severe users. Correlations between the amount of use and medial temporal lobe volumes have been described before [17, 39, 40], and abnormalities in the hippocampus and amygdala have consistently been found in (heavy) cannabis users [11, 22]. Both the amygdala [41, 42] and the hippocampal region [43] contain high levels of cannabinoid receptors making these regions likely to be affected by heavy as opposed to incidental cannabis use.

The lack of longitudinal associations between (changes in) cannabis use and changes in GM volumes over time, however, makes it unlikely that our cross-sectional differences in GM volumes are the result of heavy cannabis use. Another explanation is therefore that our cross-sectional findings represent a vulnerability factor for the development of cannabis use related problems (including the inability to control the amount of use). Cheetham et al. (2012) found that smaller orbitofrontal cortices at age 12 predicted initiation of cannabis use by age 16, but temporal regions did not predict later cannabis use [44]. On the other hand, in alcohol users, smaller temporal lobe volumes have shown to be a risk factor for alcohol abuse, rather than a consequence [45, 46]. This may imply that for substances like alcohol and cannabis, regional brain volume may be indicative for later substance use, and thus a pre-existing risk factor. This interpretation is further supported by our finding that the negative correlation between the medial temporal lobe GM volume and cannabis related problems was dependent on the severity of both alcohol and nicotine dependence. This may imply that a small medial temporal lobe is a vulnerability factor for substance dependence in general. The amygdala is involved in drug reward processing and the avoidance of drug abstinence [24], as well as in cue-elicited craving [47], whereas the hippocampus is supposedly involved in the learning of affective states in relationship to drug intake [48]. Structural deviations in these regions could render a subject more vulnerable to the development of substance dependence...

Conclusion
The lack of significant differences in GM volumes changes between young adult heavy cannabis users and healthy controls over time suggests that heavy cannabis use does not reduce regional GM volumes in this period. The cross-sectional negative correlations between medial temporal lobe volumes and the severity of cannabis use can either be a result of heavy cannabis use before early adulthood (with maximized damage before the onset of the current study) or represent a (genetic) vulnerability factor that was already present before the start of the study or even before the onset of the use of cannabis. Future studies should address these hypotheses in prospective designs in subjects that are drug naïve at the start of the study.

 

[little maggie]

It may be familiar to others but I hadn't heard about the possible effects of CBD in relation to THC. Interesting.

 

[archangelz001]

Thanks for those 3 studies @EverythingsHazy.

Study #1 is pretty objective and makes an effort to NOT overstate negative conclusions.

Study #2 is from the Am Journal of Addiction, a journal that will likely never publish anything except negative assessments of all cannabis use. 16 of the 48 subjects are in prison . One of this studies findings is that 100% of those in the study had "organic brain dysfunction in a test of visual memory immediate recall." This is OBVIOUSLY not a random sample of the general population and could never be used for predictive purposes or general applicable conclusions. The study sample population is quite extraordinary.

Study #3 contains the most objective and least pejorative attitude towards cannabis and I'm surprised you didn't highlight this conclusion because it's actually very good: "...a small medial temporal lobe is a vulnerability factor for substance dependence in general" and not the result of any amount of cannabis use. And this final one: "The lack of significant differences in GM volumes changes between young adult heavy cannabis users and healthy controls over time suggests that heavy cannabis use does not reduce regional GM volumes in this period. The cross-sectional negative correlations between medial temporal lobe volumes and the severity of cannabis use can either be a result of heavy cannabis use before early adulthood (with maximized damage before the onset of the current study) or represent a (genetic) vulnerability factor that was already present before the start of the study or even before the onset of the use of cannabis."