Καναβιδιολη σαν φαρμακο για σχιζοφρενεια (αρθρο του Guardian)
http://www.theguardian.com/society/2...s-david-potter
In an enormous glasshouse a few hours from London, there’s a powerful, unmistakable smell in the air: it’s the one that seems to cling to some surly teenagers and drifts around on the breeze at pop festivals. Here, 30,000 cannabis plants sway gently beneath giant fans and immensely bright lights. Only the remarkable uniformity of the plants – and the people walking round in lab coats – tells you the place isn’t some drug lord’s illicit cannabis factory.
This is the only research facility in the UK licensed to grow cannabis on a vast commercial scale. Here, Dr David Potter has overseen the production of nearly 2m cannabis plants, mostly for medical research or the production of the cannabis-based multiple sclerosis drug Sativex. He is director of botany and cultivation for GW Pharmaceuticals, a company that is exploring how cannabis could help treat a range of illnesses ranging from epilepsy to cancer.
Recently Potter and GW’s team have turned their attention to developing a cannabis-based treatment for psychosis and related illnesses such as schizophrenia. For a drug that is widely seen as a trigger for acute psychotic illness in young users, this at first sounds preposterous. But, as Potter explains, the cannabis plant is much more than just a psychedelic weed.
“The most well-known ingredient in cannabis that gets people high is THC [or tetrahydrocannabinol],” says Potter, who often travels to give talks in London carrying a suspicious-smelling suitcase of the plants. “But THC is just one of dozens of potentially useful cannabinoids in the plant.”
Cannabinoids are chemicals that act on the brain’s cannabinoid receptors, part of a system that regulates a variety of physiological processes including pain sensation, mood, memory and appetite.
In high doses, THC can induce temporary schizophrenia-like psychotic symptoms such as paranoia, delusions, anxiety and hallucinations. Yet cannabis also contains a cannabinoid known as CBD (or cannabidiol), which appears to have almost the exact opposite effect.
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Purified CBD has been shown to have antipsychotic and anti-anxiety effects, and can lessen the psychotic symptoms normally experienced by people given high doses of THC. Research by University College London also suggests that people who smoke cannabis rich in CBD are less likely to experience “schizophrenia-like symptoms” than those who smoke cannabis containing only THC.
Unfortunately for the mental health of many young cannabis users, the chemical profile of the drug has changed drastically over the past three decades. Not only does modern cannabis contain more than twice as much THC as it did in the 1960s, it also now contains hardly any of the “neuroprotective” cannabinoid CBD.
Potter has analysed countless samples of street cannabis on behalf of the Home Office and the police, in parallel to his work cultivating the plant for medical research. With this “library” of cannabis samples and seeds stretching back decades, he has been able to track exactly how cannabis has changed.