The brain's own antipsychotic medication

Anandamide is a cannabis-like substance produced by the brain. Researchers at the University of Cologne and UC Irvine who observed that schizophrenics have higher adandamide levels than healthy individuals. The odd thing though is that within the group of people suffering from schizophrenia, the individuals with the most severe symptoms had the lowest anandamide levels. The new theory is that rather than causing psychosis, anandamide helps control it and that those with the worst symptoms might be producing too little of the substance in response.

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.

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Update: As our friend at root.cellar points out, ananda, the root word of Anandamide, is Sanskrit for "bliss." Appropriate! Link