A cannabis-like substance produced by the brain may dampen delusional or psychotic experiences, rather than trigger them. Heavy cannabis use has been linked to psychosis in the past, leading researchers to look for a connection between the brain’s natural cannabinoid system and schizophrenia. Sure enough, when Markus Leweke of the University of Cologne, Germany, and Andrea Giuffrida and Danielle Piomelli of the University of California, Irvine, looked at levels of the natural cannabis-like substance anandamide, they were higher in people with schizophrenia than in healthy controls.
From New Scientist:
How our brains fend off madness
A cannabis-like substance produced by the brain may dampen delusional or psychotic experiences, rather than trigger them.
Heavy cannabis use has been linked to psychosis in the past, leading researchers to look for a connection between the brain’s natural cannabinoid system and schizophrenia. Sure enough, when Markus Leweke of the University of Cologne, Germany, and Andrea Giuffrida and Danielle Piomelli of the University of California, Irvine, looked at levels of the natural cannabis-like substance anandamide, they were higher in people with schizophrenia than in healthy controls.
The team measured levels of anandamide in the cerebrospinal fluid (CSF) of 47 people suffering their first bout of schizophrenia, but who had not yet taken any drugs for it, and 26 people who had symptoms of psychosis and have a high risk of schizophrenia. Compared with 84 healthy volunteers, levels were six times as high in people with symptoms of psychosis and eight times as high in those with schizophrenia. ”This is a massive increase in anandamide levels,” Leweke told the National Cannabis and Mental Illness Conference in Melbourne, Australia, last week. And that is just in the CSF. Levels could be a hundred times higher in the synapses, where nerve signalling is taking place, he says.
But were the high anandamide levels triggering the psychotic symptoms or a response to them? Leweke and his colleagues found, to their surprise, that the more severe people’s schizophrenia was the lower their anandamide levels. The team’s theory is that rather than triggering psychosis, the substance is released in response to psychotic symptoms to help control them. People with the worst symptoms might be unable to produce sufficient anandamide to prevent them.
At some point in their lives, between 5 and 30 per cent of healthy people have had symptoms such as delusions or hallucinations, which can be triggered by something as simple as sleep deprivation. ”All of us are potentially psychotic,” says David Castle of the University of Melbourne. So for the body to have a system that prevents these experiences getting out of hand makes sense, he says. The new findings suggest antipsychotic drugs could be developed that target the anandamide system, but it will not be simple. The active ingredient in cannabis, THC, binds to anandamide receptors. But people with schizophrenia who use cannabis actually have more severe and frequent psychotic episodes than those who do not. This may be because THC makes anandamide receptors less sensitive. Leweke’s team also found anandamide levels lowest in people with schizophrenia who used cannabis more frequently, suggesting it may disrupt the system in other ways too.
The researchers find a correlation between high anandanide levels and schizophrenia. Cannabis increases the anandanide levels and seems to make schizophrenia worse.
Then there are two contradictory pieces of evidence which they try to incorporate into the revised theory that the body uses cannibinoids to fight madness. 1. people who smoke cannabis tend to have lower incidence of schizophrenia. 2. anandanide levels in schizophrenics go down as the symptoms get worse.
It seems like the first contradiction can easily be explained by the self-selecting nature of pot-smokers. People prone to paranoia don’t smoke. This evidence doesn’t support the argument that the body uses natural cannibinoids to fight schizophrenia. That’s my observation, and I’m sticking with it.
That leaves the second contradiction: anandamide levels go down as the disease progresses. The reasoning that the body uses anandamide to fend off schizophrenia seems like an extremely convoluted and unlikely explanation to this mystery.