Oliver Sacks, the neurologist and author of The Man Who Mistook His Wife For A Hat, died on August 29 2015 aged 82. This interview by Adam Higginbotham first appeared in the Telegraph's Seven magazine in November 2012.

In his third year at Oxford, as an undergraduate studying biology and physiology, Oliver Sacks was not yet 20 years old when he first decided to take LSD. It was 1953, and the drug was still perfectly legal; Sacks and his childhood friend Eric Korn simply wrote to the headquarters of Sandoz Pharmaceuticals in Switzerland and ordered their acid through the post. “It didn’t have any bad reputation,” Sacks says now. “It didn’t have much reputation at all at that time.”

When their single tablet – 50 micrograms – of LSD arrived, Korn and Sacks prepared for their impending trip with great care. “There was a sense of ritual,” Sacks explains. In his basement digs, not far from the Radcliffe Science Library, they divided the tablet in half, and solemnly laid out two glasses of water. Finally, Sacks selected some music to accompany them on their journey. “The Firebird. I thought Stravinsky would go nicely.”

The pair toasted one another, and each swallowed their dose. Not quite knowing what to expect, Sacks put on the Stravinsky record, and then: nothing. “It sounded… as it always sounds,” he says. They waited for an hour, during which neither he nor Eric could detect even the hint of an effect of the drug. Eventually, they gave up in disappointment. Later, Sacks realised that they had underestimated the effective dose of LSD by a factor of 10. “We should have ordered 500 micrograms, not 50,” he writes in his new book, Hallucinations.

It was not a mistake he would make again.

Now 79, Sacks may be the world’s most well-known neurologist. His four decades of writing have brought popular illumination to areas of brain science once confined to the arcane corners of specialist literature, dramatically expanded awareness of syndromes like Tourette’s and elevated the medical case history to an art form. His clinical anecdotes – drawn from collections including The Man Who Mistook His Wife for a Hat and the bestselling Awakenings, which described his work in the late Sixties at the Beth Abraham Hospital in the Bronx, treating survivors of the Twenties epidemic of encephalitis lethargica or “sleepy sickness” – have been adapted for theatre and film, a ballet, and an opera by Michael Nyman. The patients he has written about have ranged from the man whose alcoholism had robbed him of 20 years of memories, eternally convincing him that he was a sailor on leave at the end of the war, to the musical synaesthetes described in Musicophilia, who can “see” luminous colours associated with each note in a scale.

Lately, he has turned his attention increasingly inward. His memoir, Uncle Tungsten, described a boyhood ensorcelled by chemistry, framed by the compassion and dedication his parents – his father, a north London GP and his mother, a surgeon who studied under Marie Curie – showed their patients, but overshadowed by his years spent at a boarding school overseen by a sadistic and abusive monster.

Oliver Sacks's strangest cases

We meet in his apartment, in an anonymous red-brick building, in New York’s West Village where he has lived since 1965. The walls of the living room, where he writes on an electric typewriter overlooking the street, are lined with books, shelved and labelled by category (“ferns”, “natural history”); there is a grand piano, and a fluorescent orange fedora rests on a side table. The decades spent in the United States have left little mark on Sacks’s accent, an Oxonian tapestry of sibilant Ss and soft Ws. A lifelong sufferer from prosopagnosia – “face blindness” – he is unable to recognise individual faces, including his own reflection in a mirror; he has learnt to identify those he knows well from their silhouettes. But, despite being notoriously clumsy, blind in one eye – following an operation to remove a tumour on his optic nerve – and often walking with a stick, he seems spry and fit. At one point he hoists his leg onto the table in front of us to show me the colour of his socks, turquoise.

Until now, Sacks has deliberately left the period between the end of his childhood in Britain and the beginning of his clinical work in New York in 1966 unexplored in his writing. But Hallucinations now provides a glimpse into what he calls “the hole in the middle”. Most of the book takes a similar form to Sacks’s previous collections of case histories, recounting the unusual stories of patients he has read about or treated himself. Hallucination is a subject that has long fascinated him, but also one he believes deserves wider attention, in the hope that it can be defused. “The whole subject is under-reported, because people are afraid to mention hallucinations. People may feel that hallucinations denote severe mental illness, dementia, or something massively wrong. But for the most part, they don’t.”

Hallucinations of all kinds are startlingly common. Sacks cites a study by a Dutch colleague, who examined 600 people who were blind or had very poor vision, and found that 15 or 20 per cent had elaborate hallucinations – faces, landscapes, animals – and 80 per cent had simpler ones of geometric shapes.

In the book, he also relates the stories of individuals suffering from a wide spectrum of perceptual anomalies: visual, aural, olfactory and, in the tales of amputees troubled by phantom limbs, tactile. But the most interesting case that he describes is his own.

Oliver Sacks qualified as a doctor in 1958 and, after spending a year as house surgeon at the Queen Elizabeth Hospital in Birmingham, in the summer of 1960 left Britain for Canada, ostensibly on holiday. But soon after he arrived there, he sent his parents a single-word telegram: “STAYING.” He fought fires in British Columbia, toyed with joining the Royal Canadian Air Force and eventually rode the bus from Vancouver to San Francisco. There, he befriended the poet Thom Gunn and began going by his middle name, Wolf. “When I got to the West Coast,” he says, “I wondered if I could shrug off some of my Old World identity with my first name.” It was not the only change with which Sacks began to bury the well-brought-up young man from NW2: over the next four years, he went on to ride his Norton Scrambler across the US, take up surfing, hang out with the Hells Angels, join the weightlifters in Muscle Beach – and recklessly experiment with a dizzying smorgasbord of psychoactive drugs. This last he describes in sometimes terrifying, and occasionally hilarious, detail in a single chapter of Hallucinations.

When he arrived in the US, Sacks’s chosen field of medicine was already undergoing a revolution, as neurologists and psychiatrists began exploring the ways in which neurotransmitting chemicals allowed the different parts of the brain to communicate with one another. The mysteries of how drugs like LSD and cannabis worked on these neurotransmitters were at a new frontier of serious study. “Neurochemistry was plainly in,” Sacks writes, “and so – dangerously, seductively, especially in California… were the drugs themselves.”

After taking a residency in the neurology department of UCLA medical centre in Los Angeles in 1962, he began smoking cannabis and took more LSD; he shot morphine and gobbled down handfuls of pulverised morning glory seeds, a powerful natural hallucinogen, mixed with vanilla ice cream to make them more palatable. Moving to New York in 1965, he would leave work on Friday evenings to spend the weekend on “drug holidays”, gobbling down amphetamine pills, up to 400 in two days. He experienced some truly spectacular hallucinations: on one trip, he heard his parents arriving for a surprise visit, in his Topanga Canyon garden, via chartered helicopter – only to burst into tears when he realised he had imagined it all; on a massive dose of morphine, he lay in bed for 12 hours watching the Battle of Agincourt take place on the sleeve of his dressing gown; using a cocktail of cannabis, amphetamine and LSD, he successfully set out to envision a splash of true indigo, the colour he had been fascinated by since childhood.

But it was also during one weekend speed binge in 1967 – during which he sat down at home and read all 500 pages of a Victorian treatise on migraines in one sitting – that he first realised he might be capable of producing medical writing that combined science and humanism in a way that by then had been unfashionable for a century. It was the last time he ever took speed. Soon afterwards, he began work on the book that launched his career as a writer, Migraine.

He now says that, among other things, his use of LSD may have helped develop in him the empathy that vividly animates his best case histories. But he certainly wouldn’t recommend taking it. “Oh, no,” he tells me urgently, as if I might have some in my pocket, ready to swallow on his endorsement. “I certainly don’t recommend. I did a lot of things very foolishly – I think there was something destructive in me, and I often took high, and risky, doses.”

In retrospect, Sacks concedes, he may have become an addict. “I certainly had a compulsion – a dangerous compulsion with amphetamines, and a sort of insatiability,” he tells me. “And if that defines an addiction, then I had it.”

Sacks has written about his own drug use once before, almost 30 years ago, in “The Dog Beneath the Skin”, a case history included in The Man Who Mistook His Wife for a Hat. But in the story – of a young man who spends a night taking speed, cocaine and PCP and awakes to find that he has an acutely heightened sense of smell – Sacks concealed his identity behind a pseudonym: “Stephen D., aged 22, medical student.” Sacks acknowledges this with a little reluctance. “I’m, um… less – less shy now. I think partly I’m at a distance from these things. They were 40 years ago. And I don’t think it’s sensationalism or exhibitionism for its own sake – so much as the fact that I am basically constituted the same as everybody else, and I will get an inside take, as well as a scientific one.”

Sacks is fond of telling the story of how his father, Sam, retired as a GP at 70, but went back to work 48 hours later, then re-retired at 80 and did the same thing. “At 90, we said, at least stop the house calls,” he has said, “but he stopped everything else and stayed with the house calls, which he did until his 95th year.”

As he approaches 80, Sacks continues to see a handful of patients every week, and receives hundreds of letters every year. Many concern complaints and symptoms related to his latest piece of writing, but some topics prove more enduring than others: the musical phenomena discussed in Musicophilia, especially. Sacks replies to some, and others – if they’re nearby – he will meet personally to discuss their symptoms. These correspondents have proved invaluable to Sacks’s writing: in addition to the case histories of long-standing patients he includes in Hallucinations, he says that the book also draws on letters from more than 80 different individuals.

In the past, Sacks has been criticised for exploiting his patients, or for simply applying a sophisticated gloss to the principles of a carnival freak-show – leading to the review in which sociologist and disability rights campaigner Tom Shakespeare glibly dismissed him as “the man who mistook his patients for a literary career”. But he maintains that he has always taken great care over the feelings and privacy of his patients. “It may not occur to me to write anything about them until I’ve been seeing quite a lot of them,” he says. And if it does occur to him, then he discusses the possibility at length with both patients and their families, and in some cases gives them the drafts of the finished stories, to be assured of their approval before publication. He dislikes using real names, even when the subjects themselves might be comfortable with it. “I’ve been on a slightly delicate edge, writing about my patients,” he says. “My own conscience is the first to become activated. At one time I constantly misread the word 'portrayal’ as 'betrayal’ and 'publish’ as 'punish’, and I had to fight against my own inhibitions. And, of course, these came up in reference to my own story in Hallucinations.”

For all the apparent candour Sacks exhibits in the new book, the window it provides into his experience of the Sixties is a narrow one, swiftly shut. In conversation, he remains evasive about other details of his life during that time. At one point, I tell him that I’d supposed the reason he had left a hole in his autobiographical writing was because he’d hesitated to write about his drug use. “Well,” Sacks says, “there are all sorts of hesitancies,” and quickly changes the subject. And while he may once have seemed content to be characterised as an asexual eccentric – home alone with his collections of ferns and glinting samples of transition elements – there are hints in the book of more conventional appetites.

I mention that among the handful of things that he describes making his life difficult when he first moved to New York – his research was going badly, he just wasn’t cut out to be a bench scientist – was a love affair that had gone sour.

“Ah,” he says warily, as if reluctantly owning up to some misdemeanour.

How many times, I ask, have you been in love? “Um. Four or five. I forget. But otherwise, no comment.”

It’s one area of your life that seems very mysterious. Is that deliberate?

“Yes. Perhaps so. There’s been a strong inhibition – to use the word my analyst uses. Although I have feelings, I’ve never lived with anybody, made commitments – and somehow have none the less got to 80. I have no particular complaints there.”

Oliver Sacks Credit: Rex Features

The relationship with his psychoanalyst, Leonard Shengold, a Manhattan-based Freudian specialist in child abuse and childhood trauma, is one of the most enduring in Sacks’s life. In the dedication of The Man Who Mistook His Wife for a Hat, Sacks describes Shengold as his mentor; he has seen him twice a week almost every week for 45 years, and continues to do so. “I saw him yesterday,” Sacks confirms, “and I’ll see him tomorrow.”

Whatever benefits they have brought him as a writer, the neurologist in Sacks is aware that his years of drug abuse may have left their mark on his health: “I think anyone who has been addicted – or perhaps one should use a vaguer word, and say irresponsible – is potentially a candidate, maybe for the rest of their life.” And although Sacks has no problems with drinking – “Alcohol does nothing for me,” he says – food can be difficult.

“I’m a compulsive eater. I can’t have much food in the fridge.” Sacks has eaten the same meals every day for years: oatmeal or Grape-Nuts for breakfast, and canned fish for lunch and dinner. When I ask about this, Sacks stands and shuffles off toward the kitchen, “Stay put,” he instructs. He returns a minute later to methodically stack on the table between us seven tins of sardines, and a half-finished plastic-wrapped package of canned, pickled herring. “I keep a small stock,” he explains. “I don’t want to be bothered to make a choice. Lunch or dinner usually takes about 30 seconds, and I eat standing up. And sometimes reading a book.” If he goes out to eat with friends, Sacks will often choose the first thing he sees on the menu. “It saves time,” he explains.

He glances for a moment at the piles of tins on the table. “I’m sorry. Shouldn’t have brought this out. But I thought you might think, you know, he just talks – he doesn’t really do this. So I thought a small demonstration was called for.”

Chaotically incapable of holding on to important possessions – on the long list of items that have vanished into his personal “annihilation field” is the original draft of Awakenings – much of Sacks’s personal life is now managed by a pair of assistants, who have archived his notes and journals. The week before my visit, he had begun looking through a journal he hadn’t seen in 50 years, kept in 1960; it is, he says, a time he may like to write more about. “I’m becoming sensitive to putting something in the hole in the middle.”

Occasionally, Sacks says, he still receives letters or postcards addressed to “Wolf”, an identity he dispensed with so long ago that he’ll remain puzzled for a few moments, until he remembers: “Ooh! That’s me!” He gets one letter like this every year from Los Angeles, from someone who once saved Sacks’s life, while they were surfing near Venice Beach. Sacks, hurled onto the sand by a large wave, at the last moment protected himself by flinging out an arm, which was then broken and violently dislocated at the shoulder.

“The next wave might have rolled me out again. And he saw what had happened and pulled me out of the water. I had a not-dissimilar experience about 15 years ago, off Long Island. That time, I had torn all the hamstrings off one leg. So there have been a number of risky things over the years.”

Indeed: between the drugs and the physical injuries, Sacks’s brain and body have sustained a withering amount of punishment over the past six decades. Yet, I suggest, he still seems remarkably robust.

“Well, I was once, but now I feel I’m getting rather frail. I think I tested my robustness to the limit. Perhaps slightly over the limit.”

Culture stars who died in 2015 View gallery Credit: Reuters/Rex Features

Before I leave, Sacks offers me a gift. “Would you like a tin of sardines,” he asks, “for your lunch?”