Monthly Archives: December 2015

Half a cannabis cigarette causes quasi-psychotic effects like schizophrenia in healthy people

By LIZZIE PARRY FOR DAILYMAIL.COM
3 December 2015
dailymail.co.uk/health/article-3345090/Just-HALF-joint-cannabis-causes-psychosis-like-effects-healthy-people-s-similar-schizophrenia-say-experts.html
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  • Active ingredient in cannabis delta-9-THC is linked to psychosis effects
  • Scientists do not fully understand mechanisms that cause these effects
  • Yale team found delta-9-THC increases random neural activity, or noise
  • Believe increased neural noise plays role in psychosis triggered by drug
  • Experts say effects are similar to the symptoms of schizophrenia

Smoking cannabis can induce psychosis-like effects, similar to the symptoms people diagnosed with schizophrenia endure, scientists have said.
While past research as come this this conclusion in the past, the mechanisms underlying these effects are less clear.

Now, a team of scientists at Yale School of Medicine have found the active ingredient in marijuana, delta-9-tetrahydrocannabinol (delta-9-THC) increases random neural activity, known as neural noise, in the brains of healthy drug-users.

Their findings suggest increased neural noise may play a role in the psychosis-like effects of cannabis.
Dr Deepak D’Souza, a professor of psychiatry at Yale, said: ‘At doses roughly equivalent to half or a single joint, delta-9-THC produced psychosis-like effects and increased neural noise in humans.’
First author of the study, Dr Jose Cortes-Briones, a postdoctoral associate in psychiatry at Yale, added: ‘The dose-dependent and strong positive relationship between these two findings suggest that the psychosis-like effects of cannabis may be related to neural noise which disrupts the brain’s normal information processing.’

Researchers studied the effects of delta-9-THC on electrical brain activity in 24 human subjects, who took part in a three-day study.

During the experiments, they received two doses of intravenous delta-9-THC or a placebo in a double-blind, randomised, cross-over and counterbalanced design.

If confirmed, the link between neural noise and psychosis could shed light on the biology of some of the symptoms associated with schizophrenia.

Dr John Krystal, editor of Biological Psychiatry, the journal in which the study is published, said the research marks an important part of the debate over whether cannabis should be legalised.
He said: ‘This interesting study suggests a commonality between the effects on the brain of the major active ingredient in marijuana and symptoms of schizophrenia.

‘The impairment of cortical function by delta-9-THC could underlie some of the cognitive effects of marijuana.

‘Not only does this finding aid our understanding of the processes underlying psychosis, it underscores an important concern in the debate surrounding medical and legalised access to marijuana.’

High-Potency Marijuana Could Cause Brain Damage, Psychosis

Coloradoan's Celebrate 4/20 With Marijuana Smokeout

SEATTLE (CBS Seattle) – A new study on marijuana use warns the highly-potent strains of the drug available on the market today could cause brain damage or even lead to psychosis.

British researchers studied the brains of heavy marijuana users in South London.

“If you look at the corpus callosum, what we’re seeing is a significant difference in the white matter between those who use high potency cannabis and those who never use the drug, or use the low-potency drug,” study co-author Paola Dazzan told The Guardian.

White matter in the brain transmits signals from one region of the cerebrum to another and from the cerebrum to other parts of the brain. When the white matter is impaired or damaged, it can block communication between the right and left hemispheres of the brain.

 

Dazzan blames tetrahydrocannabinol (THC), the active ingredient in pot. While most marijuana contains onlu 2-4 percent of THC, about 100 high-potency brands of pot contain as much as 14 percent THC.

“What we can say is if it’s high potency, and if you smoke frequently, your brain is different from the brain of someone who smokes normal cannabis, and from someone who doesn’t smoke cannabis at all,” explained Dazzan.

Dr. Romina Mizrahi, director of the Focus on Youth Psychosis Prevention clinic at the Center for Addiction and Mental Health in Toronto, who has studied marijuana, told Digital Journal the damage can be serious.

 “Teenagers think that cannabis is harmless,” she warned. “It is not. And for some people, it’s particularly dangerous.”

 

The study is published in the journal The Lancet.