Just 1 or 2 Experiences with Marijuana May Alter Teen Brain

Adolescent brains are going to be more vulnerable to anything

drug or environmentally related, expert says

Thomson Reuters

New findings are considered a step toward understanding the impact of cannabis on young brains.

(Ben Nelms/Reuters)

Teens who use pot just one or two times may end up with changes to their brains, a new study finds.

There were clear differences on brain scans between teens who said they had tried cannabis a couple of times and those who completely eschewed the drug, researchers reported in the Journal of Neuroscience.

There have been hints that even small amounts of pot at a young age might impact the brain, said the study's lead author, Catherine Orr, a lecturer at the Swinburne University of Technology in Melbourne, Australia. 

"Research using animals to study the effects of cannabis on the brain have shown effects at very low levels, so we had reason to believe that brain changes might occur at even the earliest stages of cannabis use," Orr said in an email.

Still, she said, "I was surprised by the extent of the effects."

With an estimated 35 percent of U.S. teens using cannabis, the new findings are concerning, the researchers noted.

Orr and her colleagues saw widespread increases in the volume of grey matter in brain regions that are rich with cannabinoid receptors. Grey matter, which is made up of nerve cell bodies, is involved in sensory perception and muscle control.

To take a closer look at the impact of mild marijuana use in developing brains, Orr's team analyzed brain scans gathered as part of the larger IMAGEN study, which was designed to look into adolescent brain development.

The researchers analyzed images from 46 14-year-olds who said they had used marijuana once or twice, as well as images from 46 non-cannabis using teens matched "on age, sex, handedness, pubertal status, IQ, socioeconomic status, and use of alcohol and tobacco," Orr said.

Brain volume

The researchers spotted clear differences between the two groups, which they suspect are due to the low-level pot use. 

They acknowledge that the study didn't actually prove that marijuana led to the differences seen in the scans. It's possible that those who chose to use weed were different to begin with and that the marijuana hadn't played a role in brain development.

In other words, they might have been brain-damaged to start.

To try to address this question, the researchers analyzed scans from a third group of teens who had not tried marijuana before they had their brain scans at age 14. By age 16, 69 of these kids said they had used marijuana at least 10 times. But their brain scans at age 14 looked no different than brain scans of other kids who had not taken up cannabis by age 16, which meant there wasn't any inborn brain difference that would have predicted who would later become a pot user.

There may be serious implications to the brain changes noted by the researchers. "In our sample of cannabis users, the greater volumes in the affected parts of the brain were associated with reductions in psychomotor speed and perceptual reasoning and with increased levels of anxiety two years later," Orr said.

The reason for the higher volume of grey matter in cannabinoid-rich regions of the brain may be related to a normal process called "pruning" which may go awry when kids use marijuana, Orr said. As young brains develop, unnecessary or defective neurons are pruned away, she explained. When the system doesn't work correctly, those cells remain in place.

This may actually support the theory I have been pushing for several years. It's an observation I have made numerous times over several decades. That is, people who smoke pot often fail to progress in terms of maturity. This may be restricted to those who start using as teens; I don't know. But I have seen many pot users who started smoking joints when they were teens, and in their 30s and 40s, still acted like teenagers with regard to their dress, their taste in music, their language, their likes in many different areas. They just don't progress as normal.

The new findings are a step toward understanding the impact of cannabis on young brains, said Dr. Michael Lynch, a toxicologist and emergency medicine physician and director of the Pittsburgh Poison Center at the University of Pittsburgh Medical Center. "It's important that there was a change," Lynch said. "Adolescent brains are going to be more vulnerable to anything drug or environmentally related."

If pruning isn't working right, "the brain may not work as efficiently as it should," Lynch said. "But I don't think we can make a final determination on that from this study."

Definitely need more study. But let's all legalize it anyway. It's just kids we're talking about. Not like it's important.

Canada, and other countries and state's rush to legalize pot has turned a generation into an experiment. When the results of that experiment come in - God help us.

Pot Heads Have Abnormally Low Blood-Flow in Their Brains

Marijuana users 'have abnormally low blood flow in every part of the brain - including Alzheimer's danger zones'

Researchers studied brain scans of 1,000 US marijuana users
They found cannabis users all had low blood flow in the hippocampus
The users also had significant restricted blood flow all over the brain
Hippocampus is key for memories, and is a ground zero for Alzheimer's

By Mia De Graaf For Dailymail.com

Marijuana users have abnormally low blood flow in virtually every part of the brain, new scans reveal.

Sophisticated imaging of 1,000 cannabis users' brains found all of them had widespread restrictions or build-ups of blood flow.

Many had abnormal blood levels in areas affected by Alzheimer's disease, such as the hippocampus.

The findings, published in the latest Journal of Alzheimer's Disease, are an ominous warning as the United States rapidly embraces recreational and medical marijuana legalization.

It comes just weeks after the White House's surgeon general, Dr Vivek Gupta, warned legalization is moving faster than research.

    Health dangers? Sophisticated imaging of 1,000 cannabis users' brains found 1,000 marijuana
    users had widespread restrictions or build-ups of blood flow (file image)

The researchers at Amen Clinics analyzed data from a broad database including 26,268 patients across the US between 1995 and 2015.

The patients - from California, Washington, Virginia, Georgia and New York - all had complex treatment-resistant issues, and all underwent single photon emission computed tomography (SPECT) - a sophisticated imaging study that evaluates blood flow and activity patterns while undergoing concentration tests.

One thousand of the patients were marijuana users. 

Comparing those patients' brain scans with 100 healthy controls, the researchers saw a stark difference in blood flow levels. 

Every marijuana user had significantly lower blood flow in the right hippocampus compared to the controls. 

Marijuana use is thought to interfere with memory formation by inhibiting activity in this part of the brain.

Shocked by findings

Co-author Dr Elisabeth Jorandby said even she was shocked by the findings, despite dealing with marijuana patients on a routine basis. 

'As a physician who routinely sees marijuana users, what struck me was not only the global reduction in blood flow in the marijuana users brains , but that the hippocampus was the most affected region due to its role in memory and Alzheimer's disease,' she said.

'Our research has proven that marijuana users have lower cerebral blood flow than non-users. 

In other words, they're stupider, but is that because they are marijuana users, or are they marijuana users because they are stupider?

'Second, the most predictive region separating these two groups is low blood flow in the hippocampus on concentration brain SPECT imaging. 

'This work suggests that marijuana use has damaging influences in the brain – particularly regions important in memory and learning and known to be affected by Alzheimer's.'

Dr George Perry, editor in chief of the Journal of Alzheimer's Disease said: 'Open use of marijuana, through legalization, will reveal the wide range of marijuana's benefits and threats to human health.

'This study indicates troubling effects on the hippocampus that may be the harbingers of brain damage.'

Dr Daniel Amen, founder of Amen Clinics, said: 'Our research demonstrates that marijuana can have significant negative effects on brain function. 

'The media has given the general impression that marijuana is a safe recreational drug, this research directly challenges that notion. 

'In another new study just released, researchers showed that marijuana use tripled the risk of psychosis. Caution is clearly in order.'

And, as mentioned before, my own observations are that pot virtually stops the maturing process in regular users, such that if you start smoking pot regularly when you are 15, when you are 35 or 45 or 55, you will still act, talk, dress, think and behave like a 15 year old. I believe it is the reason why Michael Jackson never grew beyond being a little boy.

More Scary Research into the Effects of Marijuana on Teenagers
28% of 11-15 Year Olds Using Pot in Canada - Highest Rate in the World

Smoking Strong Cannabis ‘Can Lead to Brain Damage,’ Study Finds

© Steve Dipaola / Reuters

Smoking extremely strong cannabis can lead to “significant” brain damage, a King’s College London study suggests.

The study, published in the journal Psychological Medicine, found that “skunk” cannabis damages the corpus callosum, a bundle of neural fibers that allows communication between the brain’s left and right hemispheres.

The two sides of the brain have very different functions. For instance the right hemisphere controls the left side of the body and the left hemisphere controls the right side of the body. While the Bible says, "do not let the left hand know what the right hand is doing", it is speaking metaphorically. In reality, coordination between the two sides of the body is highly recommended. And there are many other reasons the two sides of the brain should be communicating.

In Holland, where marijuana is legally sold in cafes, skunk has been reclassified as a hard drug and is therefore illegal.

The illegal drug contains high levels of tetrahydrocannabinol (THC), the chemical responsible for the high users receive.

"It has long been known that people with a psychotic illness such as schizophrenia are far more likely to smoke both cannabis and tobacco,” Marjorie Wallace, the chief executive of the mental health charity SANE, said.

She added that scientists believe there is a direct link between cannabis and the levels of dopamine, which is the (the chemical messenger in the brain which is related to psychotic experience).

Regular use of the substance can lead to more harm, according to the research.

Frequently smoking the drug could trigger mental health issues, hallucinations and slow down brain activity.

Researchers examined 56 patients who reported having had a psychotic episode and 43 healthy volunteers.

The average age of healthier participants was 27 while the average age of psychotic patients was 29.

Previous studies highlighted much higher incidents of psychosis among teenagers smoking pot than adults. This study, while not determining incidents of psychosis does indicate that it does occur in adults, as well as the damage to white matter.

Lead researcher Dr Paola Dazzan, from the Institute of Psychiatry, Psychology and Neuroscience at King's College London, said: “We found that frequent use of high potency cannabis significantly affects the structure of white matter fibers in the brain, whether you have psychosis or not.

“This reflects a sliding scale where the more cannabis you smoke and the higher the potency, the worse the damage will be.”

Co-author Dr Tiago Reis Marques said: “This white matter damage was significantly greater among heavy users of high potency cannabis than in occasional or low potency users, and was also independent of the presence of a psychotic disorder.”

Legalizing pot

Commenting on the findings, freelance journalist Rhiannon Lucy Cosslett said legalizing the drug would give users “far greater control and choice” over the strength of what they smoked.

More than two million people in Britain smoked cannabis last year. A private analysis by the Treasury found that legalizing cannabis would raise tax revenues worth hundreds of millions of pounds and result in huge savings for the criminal justice system.

In August, government ministers debated a petition signed by 200,000 people calling for the legalization of cannabis. Its prohibition was upheld, however.