Brain scans reveal how LSD affects consciousness

Drugs researcher David Nutt discusses brain-imaging studies with hallucinogens.

Researchers have published the first images showing the effects of LSD on the human brain, as part of a series of studies to examine how the drug causes its characteristic hallucinogenic effects.

David Nutt, a neuropsychopharmacologist at Imperial College London who has previously examined the neural effects of mind-altering drugs such as the hallucinogen psilocybin, found in magic mushrooms, was one of the study’s leaders. He tells Nature what the research revealed, and how he hopes LSD (lysergic acid diethylamide) might ultimately be useful in therapies.

Why study the effects of LSD on the brain?

For brain researchers, studying how psychedelic drugs such as LSD alter the ‘normal’ brain state is a way to study the biological phenomenon that is consciousness.

We ultimately would also like to see LSD deployed as a therapeutic tool. The idea has old roots. In the 1950s and 60s thousands of people took LSD for alcoholism; in 2012, a retrospective analysis of some of these studies suggested that it helped cut down on drinking. Since the 1970s there have been lots of studies with LSD on animals, but not on the human brain. We need that data to validate the trial of this drug as a potential therapy for addiction or depression.

Why hasn’t anyone done brain scans before?

Before the 1960s, LSD was studied for its potential therapeutic uses, as were other hallucinogens. But the drug was heavily restricted in the UK, the United States and around the world after 1967 — in my view, due to unfounded hysteria over its potential dangers. The restrictions vary worldwide, but in general, countries have insisted that LSD has ‘no medical value’, making it tremendously difficult to work with.

How did you get approval to give volunteers LSD?

United Nations conventions and national laws do permit academic research on heavily-restricted drugs such as LSD. In the UK, this sort of study is legal so long as the drug is not being used as a therapeutic. This was not a clinical trial: we gave LSD to volunteers who were already experienced with the drugs and took their brain scans over eight hours in the lab in Cardiff, in 2014. It took us nine months to get approval from a UK ethics committeefor the work: the research was funded by the Safra Foundation [a philanthropic foundation in Geneva, Switzerland] and the Beckley Foundation [a charity near Oxford, UK, that promotes drug-policy reform] though we needed to crowdfund through Walacea.com for the resources to analyse the data.

What were the results of the study?

To take advantage of the “long trip” produced by LSD — an eight-hour experience, compared to say four on psilocybin — we put our participants through a huge range of tests.

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