Ending Addiction for Good

Studies Show Long-Term Effects of Cannabis on the Brain

Cannabis has proven to be both damaging and addictive in two recent studies.

With the legalization of recreational marijuana in Washington and Colorado, questions about cannabis have vaulted into the public consciousness. For a couple minutes, let’s put aside policy concerns and look just at the effects of cannabis in the brain. Two studies published in top journals, both in April 2014, look inside human brains at the long-term effects of cannabis use. Is cannabis addictive? Is it safe? Let’s consider the evidence.

First, an article in the Journal of Neuroscience used MRI scans to look inside the brains of young, recreational marijuana users at regions associated with addiction. Previous studies have shown that other drugs known to be addictive affect the brain’s reward centers – especially the brain’s amygdala, which controls emotional learning, and a structure called the nucleus accumbens, which controls pleasure (including our ability to laugh). We’ve also known that adding cannabis-based chemicals to the brains of rats creates changes in these structures related to addiction. But it’s quite a leap from introducing cannabinoids to rat brains and knowing the effects of smoking pot on humans.

So a team of Harvard-led researchers recruited 40 young adults – 20 marijuana users and 20 non-users – to see if what is true in the brains of rats is also true in the brains of college students. Sure enough, human marijuana users had changes in volume, density and topography in both of the amygdala and nucleus accumbens.

“These data suggest that marijuana exposure, even in young recreational users, is associated with exposure-dependent alterations of the neural matrix of core reward structures,” the researchers write.

This study and the studies that lead up to it show that marijuana use creates physical changes in the brain associated with addiction. And, the researchers point out, these results were seen in non-dependent, young adult users. What are the effects of even heavier pot use on the brain?

That’s the question of the second study, published in the Nature journal, Neuropsychopharmacology. Again, the study used MRI imaging to ask if the effects of cannabis-based chemicals seen in rat brains are also seen in human brains. This time the study compared heavy marijuana smokers to occasional smokers to see if overall brain changes are more extreme, the more you smoke. And it looked outside just the structures of addiction to explore changes in overall brain structures: how does marijuana use affect the brain?

The study found reduced grey matter volume in nearly all brain regions that are rich in the “receptors” that can trap and respond to cannabis-based chemicals. These regions include a long list of structures, almost all of which are part of a network that controls motivation, emotion, and emotional learning. Here’s an important part: the degree to which these brain areas changed was due to one of two things – either heavy use or starting use during adolescence. Long-term heavy users had the same reductions in grey matter volume as lighter users who started in their teens.

So let’s revisit our two questions. Is marijuana addictive? Yes, and a real, visible change in the brain’s reward system. And is marijuana safe? No, and the younger you start or the more you use over time, the more dangerous it is to your brain. Whether or not you believe recreational marijuana should be legal, it’s time to admit its power as a dangerous, addictive drug.


Richard Taite is founder and CEO of Cliffside Malibu, offering evidence-based, individualized addiction treatment based on the Stages of Change model. He is also co-author with Constance Scharff of the book Ending Addiction for Good.

I would like more detailed information please...

The study may show long-term effects of cannibis use but this article doesn't. We're not all neuroscientists so we are not going to further investigate and download this study to read more about it. So why not state the specific symtoms of having reduced gray matter from cannibis use? Why does this article not give details?

Also the study should correleate the reduced brain matter with tests of psychological health of the individual, relationship health, and proffesional occupation. I wish the scientests furthered their research but that might be too much work for whoever is funding this binary study. Either way this article has too little information. I love studies and articles but this one makes no effort to explain the real-world daily life implications of having your gray matter reduced by cannabis use. It's just internet fluff trying to get view counts.

Gosh, a treatment provider who

interprets heavily criticized "studies" that support his profession. Hoodathunk?

Logic and Good Studies

I'm not a marijuana proponent but both these studies are limiting at best. While the study appears conclusive on the surface, it falls very short in the long run. In the full article the authors state a causative relationship between the cannabis use and the anatomic changes throughout the article, only to state in the second-to-last paragraph that no causative relationship can be concluded.
A plausible alternative interpretation of this data is that the neuroanatomical abnormalities predate the drug use and make the individuals more likely to use cannabis. By reversing the causative relationship here, we would suppose that greater anatomical changes would cause increased consumption.
As noted, there is evidence showing an empirical link between tetrahydrocannabinol administration and neuroanatomical changes in rodents not humans.
A causative relationship based solely on this abundantly flawed 20 person group study is simply not present.

A question about duration

From the article and the studies I'm unable to tell whether or not the neuroanatomical changes were observed straight after the application of the cannabinoids or after some time without use. When speaking of long term effects, I would think it an important piece of information to know whether the effects last even after use of the drug has ceased and as cmw stated, whether or not the abnormalities existed before the post use tests.

Long term use of Marijuana

This person has no idea what he is talking about. I do not support the recreational use of Marijuana because for some people this drug is addictive. Not physically like Heroin but for some it can be addictive. I believe what a person does with their own body is their own business and nobody else. That is one of the major problems of this country is too many people are worried what somebody else is doing. I know if I want to do something as long as it effects me and only me nobody better try and tell me what to do or not do and that is including a police officer. As far as marijuana goes I used to smoke in very high doses about 1 pound a month. As far as learning they are full of crap. I even had a person tell me once I have this amazing memory for facts but I never remember who told them to me. I remember phone numbers I have not dialed in over 35 years. When I smoked pot I was real slow at doing math equations but now it has been over 9 years since I touched the stuff and I will challenge anybody to do math equations faster than me. My wife won't even use a calculator with me around because it takes her longer to punch it in than it does for me to give her the answer. I don't like what it did to my problem solving ability and I don't like being addicted to something. Now they even make a Marijuana that you can't evemn get high on called Avidekel. It is only .05% THC but it is 15.8% CBD. It is from Israel and it cost $320.00 for 15 seeds and I just ordered some. People that want the medical will not want the high THC because it is counter productive. I also emailed the Governor of my state the state police the FBI and the DEA and I told them all I will be growing it and I ask for no ones permission. I will destroy anybody who tries to take it from me. It cures cancer it helps with Parkinsons it lowers blood pressure and all sorts of other stuff. Check out Cash Hyde from Montana the government murdered this 4 year old child. He was two when he was diognosed with a brain tumor and was terminal. He got to a p[oint he had gone 40 days without eating. The doctors had told the father there is nothing we can do. The father tried something else. He got some Marijuana oil and started using it. By the time Cash was 3 years old the doctors couldn't believe it but he was totally cancer free. Then the government stepped in and took away the fathers ability to get the oil and longer. By the age of 4 the cancer had returned and Cash Died. That government needs to be brought up on murder charges and they will be because I am making it a priority. Who ever is responsible for Cash's death will be brought up on Homicide charges. In 1974 The Medical College of Virginia because of Richard Nixon ordered studies done on Marijuana and that is when they discovered marijuana cures cancer. Yhey shgut studies down because they were being paid off by prescription drug companies to keep it illegal. In 2001 the U S Government filed patent #6630507 which is a patent on Marijuana. You can type those numbers in for your self and see. How many people have been murdered by our government since 1974? I can back up everything I am saying. We are listed as the 24th most corrupt government in the world. The scumbag that wrote the first post works for the government trying to keep it illegal and I have no respect for that piece of crap and deserves to be shot. He is trying to brainwash everybody and I will gladly meet this person and have a debate. I will destroy him with facts. This country is headed for another revolution because of scum like the person that wrote the first article. Like I said I can back up everything I say with facts and I challenge this person to a public debate. They won't have the guts however because this person knows they are spreading lies. Everything I put in you can research because type any of it in and you will see. There was also another study where 26 all stage 4 cancer patents which stage 4 means terminal. They took no other treatment and at the end of 6 months 1 had died and the other 25 were cancer free. So as you can see if anybody tries to take my avidekel it could cost them their life. My wife has Parkinsons and I have a bad heart and have had pre cancerous polyps on my colon. I figure my life or theirs. I refuse to get the card because I will not ask the government for permission for something they have no right to tell me I can or I can't. They don't own me I am not their possession and I will gladly die before I will give in. Gets some guts people and stop letting our tyrannical leaders tell you want to do. They are supposed to be public servants but it seems we are their servants. I am part of a Militia and we are trying to stay non violent but we will not be pushed around and the government best take notice.

More Marijuana facts

Marijuana oil cures 25 out of 26 stage 4 cancer
But it might be money well-spent. All 26 of Finley's referrals had stage 4 cancers -- brain tumors, colon cancers, lung cancers -- which means the malignant growths had metastasized to other organs. Most had prognoses of a few months to live, some had less than six weeks. All complemented modern Western medicine treatments such as chemotherapy with the concentrated oil -- and all but one have survived, she says. A patient's prognosis can very widely depending on the type of cancer, but the disease is a reliable killer at stage 4, meaning Finley's patients' 96 percent survival rate is unheard-of.

"I'm not a stoner," she says now, almost defensively, noting that classmates at Oakland-based cannabis grow college Oaksterdam University, where she honed her cultivator skills, at times mistook her for an undercover cop. "It was against my own prejudice that this could really be true."

These survival stories are becoming more common. One of the most high-profile was the case of Montana toddler Cash Hyde, diagnosed with a brain tumor at 20 months, whose family credits cannabis oil for keeping the tumor at bay and keeping him alive -- until a change in Montana state law cut off his access to oil for a few months. The tumor returned and he died in November, at age four.

These stories are remarkable, but for now they're also just stories -- which means they're all but worthless to the medical community, which needs hard data. "Anecdotes are not evidence -- you need to do research, controlled studies," says Dr. Donald Abrams, the chief of oncology at San Francisco General Hospital and an integrative medicine specialist at the University of California at San Francisco. Abrams, a personal friend of the Aldriches who has researched cannabis's medical value extensively -- and is a believer in its value -- is still a scientific skeptic. "I hear stories all the time -- 'I was cured of cancer by this or that' -- and most of the time it's frankly bogus." We need to stand up and revolt. The state of Montana murdered that child. How much longer are you going to allow this government to control us. I refuse to ask the government for the right to use marijuana. I got arrested once for possession but I didn't know all this at the time. No cop will ever take it from me again and if he tries he wants to have a army backing him up. The government is a murderer why shouldn't they be killed. They killed that little child.

Great article I'm glad this

Great article I'm glad this has come out. I live in a street with lots of older guys who've been smoking pot heavily for years , it takes them years to do anything that would take anyone else a few days & the job is done poorly if it's ever finished. They also don't seem to be able to tell the difference between junk & something valuable or a stupid idea from a brilliant one. There also seems to be a theatricality about what they do, they want attention for their pathetic antics.

I used to like the neighborhood because I was a heavy drinker, they provided excellent "cover" but after reading the remarkable book "Willpower. Rediscovering the Greatest Human Strength" (by Baumeister & Tierney) I quit, didn't even even read the book in order to quit. Now I'm thinking what the hell am I doing here?!

I think addiction is symptomatic of our societies emphasis on self-esteem & how one feels over self-control and how things actually are, drugs make things seem good and make you feel good about yourself but they're actually making both worse.

But I think 'well- adjusted' people are just as likely to be addicted to consumerism in the same way, they're busy destroying the planet to feel good with the latest mindless purchase, perhaps they're worse than the pot-heads?


Lets nip this uneducated fool in the bud. First of all type in your search bar 6630507 it is a patent the government applied for in 2001 and attained it in 2003 on Marijuana and its many health benefits. You talk about a person taking forever to get anything done. I quit smoking Marijuana 9 1/2 years ago so I am not defending the right to get high. Also if I want to get high it is none of your business so keep your nose out of it. Second Cannabinoids are in Breast milk. Read link below.
Without it your baby would most likely die. So tell me again why Marijuana is bad? Also you do not need to smoke it you can take a tincture which I do now for insomnia and you do not get the ephori feeling at all. They used marijuana for medicine in this country from 1850 until 1937. Henry Ford even made an all hemp car which weighed 1000 LBS less than its counterpart and when hit with an ax they couldn't put a dent in it. Dr. Constance Finley from CA has a 96% success record from curing stage 4 cancer. Read link below.
After reading all this if you want to follow the uneducated fool that wrote the previous ad then go ahead because it could be your chance to die with cancer. The person that wrote the previous ad is looking at it like a junkie not a medical point of view. Also marijuana lowers blood pressure. I do not suggest anybody smoke it take the liquid. Smoking anything isn't good for your lungs. I could easily tell you so much more but that is enough for now.

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Richard Taite is CEO and founder of the Cliffside Malibu Treatment Center in Malibu, California and co-author of the book Ending Addiction for Good.


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