Teenagers who smoke cannabis damage their brains for LIFE and may be more likely to develop schizophrenia
- U.S. study found that mice exposed to even small doses of marijuana for 20 days suffered lasting brain damage into adulthood
- Results highlight how teenagers who regularly smoke weed may have a greater risk of developing schizophrenia
Teenagers who regularly smoke cannabis suffer long lasting brain damage and are in much greater danger of developing schizophrenia.
American researchers say the drug is particularly dangerous for a group of people who have a genetic susceptibility to the mental health disorder - and it could be the trigger for it.
Asaf Keller, of the University of
Maryland School of Medicine, said the results highlight the dangers of
teenagers smoking cannabis during their formative years.
The study found that even short-term exposure to cannabis impaired brain activity, with the damage continuing into adulthood
The study, published in the journal Neuropsychopharmacology, exposed young mice to the active ingredient in marijuana for 20 days.
It found that their brain activity was impaired, with the damage continuing into adulthood.
The past 20 years has seen major controversy about the long-term effects of marijuana, with experts divided over its long-term effects on teenagers.
Previous research has shown that children who started using marijuana before the age of 16 are at greater risk of permanent brain damage, and have a significantly higher incidence of psychiatric disorders.
‘Adolescence is the critical period during which marijuana use can be damaging,’ said the study's lead author, Sylvina Mullins Raver, a PhD candidate at the University of Maryland School of Medicine.
‘We wanted to identify the biological underpinnings and determine whether there is a real, permanent health risk to marijuana use.’
The scientists began by examining cortical oscillations in mice. Cortical oscillations are patterns of the activity of neurons in the brain and are believed to underlie the brain's various functions.
These oscillations are very abnormal in schizophrenia and in other psychiatric disorders.
VIDEO: Scientists explain how cannabis damages the teenage brain
The scientists exposed young mice to very low doses of the active ingredient in marijuana for 20 days, and then allowed them to return to their siblings and develop normally.
‘In the adult mice exposed to marijuana ingredients in adolescence, we found that cortical oscillations were grossly altered, and they exhibited impaired cognitive abilities,’ said Raver.
‘We also found impaired cognitive behavioural performance in those mice. The striking finding is that, even though the mice were exposed to very low drug doses, and only for a brief period during adolescence, their brain abnormalities persisted into adulthood.’
The scientists repeated the
experiment, this time giving marijuana to adult mice that had never been
exposed to the drug before.
According to the research team, there is a group of people who have a genetic susceptibility to developing schizophrenia. Adding weed to the mix during adolescence could be the trigger that causes it to develop, permanently impairing brain function and cognition
Their cortical oscillations and ability to perform cognitive tasks remained normal, indicating that it was only drug exposure during the critical teenage years that impaired brain activity.
‘We found that the frontal cortex is much more affected by the drugs during adolescence,’ said Keller.
‘This is the area of the brain controls executive functions such as planning and impulse control. It is also the area most affected in schizophrenia.’
Keller now wants to know whether the effects can be reversed. ‘We are hoping we will learn more about schizophrenia and other psychiatric disorders, which are complicated conditions,’ he said.
‘These cognitive symptoms are not affected by medication, but they might be affected by controlling these cortical oscillations.’
CANNABIS DESTROYS YOUR GET-UP-AND-GO
A separate study by Imperial College
London last month revealed that long-term use of cannabis destroys
dopamine, the feel-good chemical in the brain that inspires a spirit of
get-up-and-go.
Previous research has suggested taking marijuana can lead to individuals becoming withdrawn, lethargic and apathetic.
The cannabis users in the study
published in Biological Psychiatry had all experienced psychotic-like
symptoms while smoking the drug such as strange sensations or having
feelings of paranoia.
The researchers expected their
dopamine production might be higher since this has been linked with
psychosis - but instead found the opposite.
The cannabis users had their first
experience with the drug between the ages of 12 and 18 and the
researchers believe the drug could be the cause of the difference in
dopamine levels.
'Cannabis is an illegal drug and
there is mounting evidence the idea of it being a harmless herb is not
true,’ said Dr Michael Bloomfield, of Imperial College London.
'When people stop taking cannabis it seems the brain can slowly go back to producing pretty normal levels of dopamine.
'Cannabis has effects on the brain and it’s important people can make an informed decision.'
Most watched News videos
- Shocking moment passengers watch bucket bomb on fire from platform
- Trump says he'll call May 'right now' over Parsons Green attack
- Laura Simpson sets the record straight on night with Wayne Rooney
- Surveillance video shows Kenneka Jenkins stumbling around hotel
- Theresa May announces terror threat level raised to critical
- South Korea stages missile drill after another launch from North
- Tomi Lahren gets tricked and insulted by ‘fan’ in Instagram post
- Passengers evacuate from an underground train near Parsons Green
- Friend shares video of Eric Bolling Jr. partying
- Hitman moves child out of the way before shooting target
- Final moments of police stand off with man brandishing fake gun
- Man shows off amazing guessing skills against Amazon's Alexa
- Violent new Muslim street gang named 269 on the rise in...
- Black box fitted to a $200,000 supercar could hold the...
- Transgender troops CAN re-enlist in the US Military says...
- High school teacher, 40, 'got so drunk drinking...
- 'What are you doing with my wife?': the chilling last...
- Forced to drink bleach, eat dog food and inhale toxic...
- 25 African-Americans thrown out of South Carolina...
- They really did take the biscuit! Sticky-fingered gang of...
- Doctor dragged off United flight was felon who traded...
- Thick layers of butter-coloured fat, a liver like pate...
- Prost! Adidas launches beer and vomit-proof trainers just...
- PICTURED: The internal medicine specialist father-of-five...
- School caretaker, 51, who drilled holes above a shower...
- Chechnya opens world's first concentration camp for...
- Job Centre fraud investigator who flew teenager from...
- Shameless rise of the 'beg-packers': Astonishing...
- Cheeky RAF pilot shocks plane watchers as he appears to...
- There's only Un winner! North Korean dictator Kim Jong Un...