Born on the line that divides Generation X and Generation Y, I’ve often felt confused about drugs. Are they meant to be a rite of passage, dipping the body in an infusion of self-destruction before life can begin? Or are they a reflection of personal choices, a distinct part of your personal brand, belonging to the ‘me’ generation?

It turns out that today’s students have ceased to be confronted with this dilemma. In response to a report from the usual panel of health experts calling for the legalisation of drugs, the government was able to say, somewhat predictably, that it had no plans to change the law. But the Home Office statement gave another reason: drug use is falling – levels are at an all-time low since records began.

The era of the rave seems to have passed. The sexiness of drugs and experimentation seems a little bit old hat. And it’s not just illicit substances, to paraphrase the Dandy Warhols, that now seem passé. This year Aberystwyth University is closing its student union bar. Meanwhile coffee shops on campus are on the rise. Sobriety is the new high. But before you start to feel nauseous with a grey caffeine headache, of course, this is all hearsay, anecdotal evidence – exactly the sort of story the press like to leap upon and make huge pronouncements about, showing them up as a sign of the times. Tonight, as in every night in term for hundreds of years someone, somewhere will be lying in a gutter having trod some unsuitable path towards excess. But drugs definitely fall victim to fashion crazes and economics, nonetheless, as writers and artists know too well.

Opium is a case in point. There is no drug that has taken such a course from ubiquity to non-existence. Naturally, prohibition itself has had a huge role to play in this – though not of the kind that its supporters might like to claim. In the nineteenth century, while Britain fought the Opium Wars (1839–42 and 1856–60) to protect trade in China, writers celebrated the drug as a sensation. The finest detective fiction of the Victorian era couldn’t resist a good puff at an opium pipe.

In The Man with the Twisted Lip (1891) Conan Doyle creates a fabulous description of an opium den on the north side of the Thames near London Bridge. Watson finds Sherlock Holmes here by chance. Not that Holmes himself actually indulged. Holmes describes the den as ‘the vilest murder-trap on the whole riverside’ and is only there to obtain evidence. Holmes preferred a good, long injection of cocaine, which he charmingly describes as one of his ‘little-weaknesses’. Wilkie Collins too succumbed to the drug’s charms, and not only in his prose. He fictionalised opium addiction for his readers in The Moonstone (1868), much to their delight; though little did they know that Collins was himself long under the influence of the drug and therefore able to relate events from personal experience. Collins had the misfortune to be prescribed the drug for the treatment of gout. As Conan Doyle notes ‘the practice is easier to attain than to get rid of’ – something the journalist Peter Hitchens might like to note given his faddish belief that addiction doesn’t exist.

The tie between literature and opium most famously begins at the end of the century before Collins and Conan Doyle with the Romantic poets, in particular Samuel Taylor Coleridge. The young poet was admitted to Jesus College, Cambridge, in 1791. Like Wilkie Collins, he started taking the drug to combat a medical complaint – a bout of jaundice and rheumatic fever. Gradually, the drug began to have an impact on his academic career. While he won a medal for an ode on slavery in 1793, he left Cambridge later that year to enlist with the Royal Dragoon Guards, presumably out of his mind with addiction. Discharged for insanity, he came back to university, but he was never to take his master’s degree. Rumour has it that one night he left his college high on opium and set out to walk to Cornwall.

Only a few years later, the drug influenced him in writing ‘Kubla Khan’ (1797). At his Somerset cottage in Nether Stowey, Coleridge had an extraordinary opium dream. He sat down to record this experience but was disturbed by a man from Porlock and detained on business for an hour. On the man’s departure, he cursed him as he had only the faint rumblings of the memory left from this extraordinary experience. Given the poem’s enduring reputation, the anger directed at the unwanted man from Porlock seems unjustified. The poem, it seems, has drugs in its veins:

                a waning moon was haunted
By woman wailing for her demon-lover!

Who could ask for a better description of going cold turkey? But for all the credit that is put at the door of the drug and its influence on writers, few could ignore the sheer hell that addiction caused. Coleridge’s friend Thomas De Quincey opined in Confessions of an English Opium Eater (1822)  ‘Thou has the keys to Paradise, oh just, subtle, and mighty opium!’. This seems hugely ironic given the suffering that it was to bring to him and to many other heavy users of the drug. Coleridge spent the remainder of his life trying to deal with his opium habit.

It is easy to dream about the romantic appeal of the poppy, to look back with rose-tinted glasses and imagine a gentle life akin to the caterpillar in Alice in Wonderland forever asking paradoxical questions and effortlessly writing poems. But the sickness and half-lives led by opium addicts, would make few misty-eyed for the drug’s reintroduction.

You don’t hear about opium too much these days. The reason? Heroin, an even worse and more addictive substance took its place. With the demands of smuggling, Heroin, being more concentrated, offered a much better means for suppliers to transport the drug. Prohibition got rid of one drug only to replace it with something much worse. You might also see the same pattern in skunk and hashish. In prohibition era America it was not unknown for people to inject themselves with whisky for similar reasons. If something is in short supply because it has been banned, just watch people concentrate it in to stronger forms and take higher doses as a result.

When the government proclaims that drug use is an all-time low, this doesn’t solve the problems, nor the aftermath of effects of prohibition that are still being felt today. Again, I find myself feeling confused about drugs.