How 'magic mushroom' chemical could free the mind of depression, addictions

 

 Think of psychedelics and you'll likely think of bright colors, hallucinations, spirituality, and an overall "mystical" experience. For centuries these drugs have been used in social, religious and medicinal contexts by cultures across the globe. But today, the ability of these drugs to alter our brain function is being tapped into as a potential therapeutic for a range of mental health conditions from anxiety and depression to addiction and obsessive compulsive disorder (OCD).

"Only by losing the self, can you find the self," explains Dr Robin Carhart-Harris, from Imperial College London. These may not be the usual words of a scientist but there is biology behind them. "People try and run away from things and to forget, but with psychedelic drugs they're forced to confront and really look at themselves," he says.

The drugs Carhart-Harris is referring to are hallucinogens such as magic mushrooms -- specifically the active chemical inside them, psilocybin. "We're beginning to identify the biological basis of the reported mind expansion associated with psychedelic drugs," he says. Psilocybin is not addictive and is interesting to researchers for its ability to make users see the world differently. The team at Imperial College has begun to unravel why.

Carhart-Harris scanned the brains of 30 healthy volunteers after they had been injected with psilocybin and found the more primitive regions of the brain associated with emotional thinking became more active and the brain's "default mode network," associated with high-level thinking, self-consciousness and introspection, was disjointed and less active.

Decreased blood flow under the influence of psilocybin in regions of the brain that are known to integrate information and mediate conscious states.

Courtesy Carhart-Harris et al. (2012) PNAS

"We know that a number of mental illnesses, such as OCD and depression, are associated with excessive connectivity of the brain, and the default mode network becomes over-connected," says David Nutt, professor of neuropsychopharmacology, who leads the Imperial College team. Nutt was formerly drug adviser to the UK government but was fired in 2009. He "cannot be both a government adviser and a campaigner against government policy," wrote a member of the British Parliament, at the time.

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