David Nutt
Based on Wikipedia: David Nutt
In 2009, the British government's top drug advisor was fired for stating a scientific fact. David Nutt, a neuropsychopharmacologist—a scientist who studies how drugs affect the brain—had publicly pointed out that horseback riding is more dangerous than taking ecstasy. This wasn't a joke or a provocation. It was data. And it cost him his job.
The episode would become a landmark in the fraught relationship between science and politics, but it was hardly the beginning of Nutt's story. Born in 1951, he had spent decades becoming one of Britain's foremost experts on how substances alter consciousness, from the medications prescribed for anxiety to the illegal drugs that land people in prison.
The Brain's Chemical Keys
To understand Nutt's work, you need to understand something about how your brain works. Imagine your brain as a massive building with billions of doors. Each door has a specific lock, and various chemicals act as keys. Some keys open doors that make you feel calm. Others open doors that make you feel alert, or euphoric, or drowsy.
One of the most important locks in this metaphorical building is called the GABA receptor. GABA stands for gamma-aminobutyric acid, and it's your brain's main "calm down" signal. When GABA binds to its receptors, it tells neurons to fire less frequently. This is why you feel relaxed after a glass of wine—alcohol enhances GABA's effects. It's also how anti-anxiety medications like Valium work.
Nutt began his career studying these GABA receptors at Oxford's Radcliffe Infirmary in the late 1970s. His focus was on benzodiazepines—the class of drugs that includes Valium and Xanax. These medications had revolutionized the treatment of anxiety, but scientists didn't fully understand why they worked.
What Nutt discovered was something genuinely surprising. Scientists had assumed that drugs either activated a receptor or blocked it. Open the door or lock it shut. But Nutt found a third option: some drugs could do the opposite of what the natural key did. He called this "contragonism," though the scientific community eventually settled on the term "inverse agonism."
Think of it this way: if GABA is a key that opens the calm-down door, and a blocker is a piece of gum stuck in the lock, an inverse agonist is a key that actively locks the door tighter. His 1982 paper in Nature describing this concept was genuinely groundbreaking—it changed how scientists thought about brain chemistry.
From Lab to Policy
Most scientists would have been content to spend a career making discoveries in the laboratory. Nutt did not stay in the lab.
After stints at Oxford and a visiting position at the National Institute on Alcohol Abuse and Alcoholism near Washington, D.C., he returned to Britain to head the Psychopharmacology Unit at the University of Bristol. But increasingly, his attention turned to a frustrating disconnect he observed: the laws governing drugs bore almost no relationship to their actual dangers.
In Britain, as in most countries, drugs are classified by how severely the law punishes their possession and sale. Class A drugs—heroin, cocaine, ecstasy—carry the harshest penalties. Class B includes amphetamines and, as of 2009, cannabis. Class C drugs are considered the least dangerous and carry the lightest sentences.
But when Nutt looked at the actual evidence—hospital admissions, deaths, addiction rates, social harm—the classifications made no sense. Alcohol and tobacco, both perfectly legal, caused vastly more damage than many banned substances. And within the banned substances, the rankings were arbitrary. Ecstasy, classified alongside heroin, had an excellent safety record compared to many legal activities.
The Horse Riding Problem
In 2009, Nutt published what became his most notorious paper. It wasn't in a prestigious scientific journal like Nature or The Lancet. It was in the Journal of Psychopharmacology, and it introduced a fictional addiction he called "equasy."
The name was a portmanteau—a word made by combining two others—of "ecstasy" and "equestrianism." Nutt argued that if we treated horse riding like we treat illegal drugs, we would have to conclude it was extremely dangerous and should probably be banned.
The numbers were striking. Horse riding causes one serious adverse event—a hospital visit, a permanent injury—for roughly every 350 times someone goes riding. Ecstasy causes one serious adverse event for roughly every 10,000 uses. In purely statistical terms, you're about thirty times more likely to be seriously hurt riding a horse than taking a tablet of ecstasy.
Nutt wasn't suggesting we ban horses. He was making a point about consistency. If the government's stated goal was to protect citizens from harm, why were some dangerous activities celebrated while others led to prison sentences?
The idea came to him, he later explained, after treating a patient with permanent brain damage from falling off a horse. He started looking into the statistics and realized that this popular, respectable hobby was objectively more dangerous than a drug that could land you in prison for seven years.
The Breaking Point
By this time, Nutt had risen to become chairman of the Advisory Council on the Misuse of Drugs, or ACMD. This was the official body tasked with giving scientific advice to the British government on drug policy. In theory, the government would ask questions, the scientists would gather evidence, and policy would follow the facts.
In practice, it didn't work that way.
Cannabis had been downgraded from Class B to Class C in 2004, meaning possession would typically result in a warning rather than an arrest. But in 2009, the government under Prime Minister Gordon Brown reclassified it back to Class B. The ACMD had explicitly advised against this change, concluding that the evidence didn't support it. The government did it anyway.
Nutt was vocal in his disagreement. In a lecture at King's College London, he presented his analysis showing that by any rational measure of harm—physical damage, addictiveness, social costs—alcohol ranked fifth among drugs, more dangerous than cannabis, LSD, or ecstasy. Tobacco ranked ninth. Under this framework, alcohol would be a Class B drug and cannabis would merely be Class C.
He argued that cannabis carried only a "relatively small risk" of triggering psychotic illness, and that the government's approach of "hunting down low-level cannabis users to protect them is beyond absurd."
The Home Secretary, Alan Johnson, fired him.
The Fallout
Johnson's stated reason was that Nutt had crossed a line from science into policy advocacy. "He cannot be both a government adviser and a campaigner against government policy," Johnson wrote. As for the horse riding comparison, Johnson called it "a political rather than a scientific point."
Nutt was bewildered. "I do not know which comments were beyond the line," he responded in The Times, "or, indeed, where the line was."
The scientific community's reaction was swift and largely supportive of Nutt. Several ACMD members resigned in protest. Les King, the council's senior chemist, quit first. Marion Walker, who represented the Royal Pharmaceutical Society, followed. Then three more scientists left after a tense meeting with the Home Secretary.
John Beddington, the Chief Scientific Adviser to the entire British government, publicly agreed with Nutt's assessment. When asked directly whether cannabis was less harmful than cigarettes and alcohol, he said: "I think the scientific evidence is absolutely clear cut. I would agree with it."
A leaked email revealed that the Science Minister, Lord Drayson, had called the firing "a big mistake" that left him "pretty appalled." The Times published an analysis showing that Nutt's controversial lecture had actually complied with government guidelines throughout.
But Nutt remained fired.
Drug Science and the Second Act
Rather than retreat into academia, Nutt launched something new. With financial backing from supporters who believed science should inform drug policy, he created the Independent Scientific Committee on Drugs, later renamed Drug Science. The organization would provide exactly what its name suggested: scientific analysis of drugs, free from political pressure.
In 2010, Drug Science published a comprehensive study in The Lancet that addressed a key criticism of Nutt's earlier work. The 2007 study had ranked drug harms, but critics pointed out that the weighting of different factors—addiction potential versus social harm versus physical damage—was somewhat arbitrary. Who decides whether addiction is twice as bad as toxicity, or three times?
The new study used something called multi-criteria decision analysis, a formal method for combining different kinds of evidence into a single ranking. The results were, if anything, more provocative than before. Alcohol emerged as the most harmful drug overall when you combined harm to users with harm to society. Heroin and crack cocaine were most harmful to individual users. But alcohol's massive social footprint—drunk driving deaths, domestic violence, healthcare costs, lost productivity—pushed it to the top of the combined list.
The paper was rigorous. It was peer-reviewed. And it was almost entirely ignored by policymakers.
Psychedelics and the Brain
While running Drug Science, Nutt also pursued another interest: the therapeutic potential of psychedelic drugs. This might seem like a contradiction—a scientist known for careful evidence-based analysis championing substances associated with 1960s counterculture—but it wasn't.
Psychedelics like psilocybin (the active ingredient in magic mushrooms), LSD, and DMT had shown promising results in early psychiatric research before being banned in the late 1960s and early 1970s. Nutt believed the bans had frozen potentially valuable research for decades.
At Imperial College London, where he moved in 2009 to take an endowed chair in neuropsychopharmacology, Nutt established what became the Centre for Psychedelic Research. His team conducted brain imaging studies to understand what these substances actually do to neural activity, and clinical trials to test whether they could help people with depression that hadn't responded to conventional treatments.
The results were striking. Psilocybin, administered in controlled settings with psychological support, appeared to help some patients with treatment-resistant depression—people who had tried multiple medications without relief. The brain imaging showed something unexpected: rather than increasing neural activity, psychedelics seemed to quiet a region called the default mode network, which is associated with our sense of self and rumination about the past and future. It was as if the drugs temporarily dissolved the patterns of thought that kept people trapped in depression.
This wasn't recreational drug advocacy. These were controlled clinical trials following the same protocols used to test any other medication. But Nutt constantly faced regulatory hurdles that researchers studying conventional drugs did not. Getting permission to work with Schedule 1 substances—the most restricted category—required navigating a bureaucratic maze that could take years and cost hundreds of thousands of pounds.
Building a Better Drink
Perhaps the most ambitious project of Nutt's later career combined his deep knowledge of the GABA system with a straightforward observation: alcohol is terrible for you, but people really like being relaxed and social.
What if you could create something that gave you the pleasant effects of alcohol—the conviviality, the loosened inhibitions, the social warmth—without the liver damage, addiction potential, and terrible hangovers?
Nutt had been thinking about this since at least 2014. Alcohol works primarily by enhancing GABA's calming effects, but it does so crudely, flooding multiple receptor types throughout the brain and body. A more targeted compound could, in theory, hit just the receptors responsible for the pleasant effects while avoiding those responsible for addiction and toxicity.
He called the hypothetical compound "Alcarelle" and founded a company, GABA Labs, to develop it. The idea attracted enormous media attention—the scientist who was fired for saying drugs should be evaluated rationally was now trying to build a better drug.
The path from concept to consumer product proved difficult. Developing a new psychoactive compound requires extensive safety testing, and regulators are understandably cautious about anything that affects brain chemistry. Nutt's team filed patents for several compounds but kept the exact chemistry confidential.
In 2021, they released a product called Sentia—a "botanical spirit" made from plant extracts known to affect GABA receptors. It wasn't the synthetic breakthrough Nutt had envisioned, but rather a commercial compromise: a legal, plant-based drink marketed as providing relaxation without alcohol. Reviews were mixed, with some users reporting pleasant calming effects and others detecting no difference from a placebo.
The Larger Question
Throughout his career, Nutt has circled around a central question: what happens when scientific evidence conflicts with political convenience?
Drug policy is an unusually stark example because the stakes are so visible. People go to prison. People become addicted. People die from overdoses. People also die from alcohol and tobacco, which remain legal. The inconsistency is obvious to anyone who looks at the numbers, yet the policies persist.
Nutt's answer has been consistent: keep generating evidence, keep publishing it, keep making the case publicly. His 2013 John Maddox Prize, awarded for "promoting sound science and evidence on a matter of public interest, whilst facing difficulty or hostility in doing so," recognized exactly this persistence.
The prize is named after Sir John Maddox, who edited the journal Nature for over two decades and was known for championing controversial research that turned out to be correct. It's given to scientists who take professional risks to communicate accurate information to the public.
Whether Nutt's approach has worked depends on how you measure success. British drug laws remain largely unchanged from when he was fired. Cannabis is still Class B. Psilocybin is still Schedule 1. Alcohol is still sold in every corner shop.
But the conversation has shifted. Psychedelic research, which was essentially dead when Nutt started at Imperial College, is now a growing field with studies running at major universities worldwide. Several jurisdictions have decriminalized psilocybin or moved toward regulated therapeutic use. The idea that drug laws should bear some relationship to actual harm is now a mainstream position, even if legislators haven't acted on it.
What Nutt Got Right—and Where Questions Remain
Critics have raised legitimate questions about some of Nutt's claims. The weighting in harm rankings involves judgment calls, not just data. Comparing individual risk (taking one pill of ecstasy) to population risk (widespread alcohol consumption) can be misleading. And some researchers have challenged his relatively optimistic view of cannabis, particularly regarding psychosis risk in heavy users.
But his core argument—that drug classification should be based on evidence rather than tradition and politics—is difficult to dispute on logical grounds. The response from policymakers has been, essentially, to acknowledge the logic while declining to follow it. Drug policy serves functions beyond harm reduction: expressing moral disapproval, signaling concern about social order, responding to media panics. Evidence is only one input among many.
Nutt understands this, which is why he shifted from trying to reform policy from inside the government to building institutions outside it. Drug Science continues to publish research and advocacy. The Imperial Centre for Psychedelic Research continues clinical trials. GABA Labs continues trying to develop alcohol alternatives.
He is now in his seventies, a Fellow of the Royal College of Physicians, the Royal College of Psychiatrists, and the Academy of Medical Sciences. He holds visiting professorships in Australia, New Zealand, and the Netherlands—countries that have, in various ways, moved faster than Britain toward evidence-based drug policy.
The horse riding paper still comes up in drug policy debates, a testament to how effectively a vivid comparison can illuminate an abstract inconsistency. If anything has changed in the years since Nutt's firing, it's that more people now recognize the inconsistency exists, even if they disagree about what to do about it.
Sometimes that's what scientific advocacy achieves: not immediate policy change, but a shift in what everyone knows to be true. The laws may take decades to catch up with the evidence. But the evidence is on the record, published and peer-reviewed, waiting for lawmakers whenever they're ready to read it.