Films are doing drugs again. The appeal is irresistible – the pure hit of human drama that comes with the needle or the rolled-up banknote. Now, a pair of new movies find two actors at opposite ends of their careers deep in the mire. In one, Beautiful Boy, modish male lead Timothée Chalamet plays Nic Sheff, a young addict lost to methamphetamine as his father David (Steve Carell) helplessly looks on. While in The Mule, Clint Eastwood directs himself as Earl Stone, a 90-year-old horticulturalist recruited by a Mexican cartel to ferry cocaine around America. Both are based on real life, in the case of the Sheffs via parallel memoirs.

Drugs are nothing if not repetitive, and so it is for the drugs movie. Artful hard work, Beautiful Boy also feels almost cosily familiar – Chalamet passing from curious kid to black-eyed wreck, tumbling through the landmarks of familial heartbreak. While his poison is crystal meth rather than heroin, the beats haven’t changed since Frank Sinatra’s hapless jazz drummer Frankie Machine shot up in 1955’s The Man With the Golden Arm.

That at least partly explains why Beautiful Boy – well acted and sensitively handled – has the air of ancient history. The events it portrays took place in the 2000s, but older days are everywhere. On screen, as in life, David Sheff is a baby boomer magazine journalist, his career built on profiles of 70s rock stars for Rolling Stone. The young Nic wigs out in a Nirvana T-shirt, tipping the wink to Kurt Cobain, undone by heroin before his suicide. Despite his background, David is baffled by the world into which his son descends – the naive parent staring distraught across the generation gap. Same as it ever was.

But then with drugs, it often feels that way. Almost half a century since Richard Nixon formally announced the US war on drugs, Donald Trump last week argued that his border wall would halt the flow of heroin and cocaine into America. In Britain, our drugs laws remain in the state of nervous confusion they have been for a generation.

Yet, directors still want what a drug movie offers – tapping into the heady mix of social significance, criminality and big emotions – so we don’t always get the uncut truth. In Beautiful Boy, David Sheff is a babe in the chemical woods, innocent of everything but a long-ago occasional joint. Desperate to understand the stuff killing his son, he goes so far as to actually try crystal meth. That, the film says, is the depth of his love.

In fact, even before publishing his book, the real David Sheff wrote that as a student in Berkeley in the early 1970s, he had – perhaps not so unusually – seen a college roommate struggle with meth and taken it himself. But that would have spoiled the scene, of course, and added too much nuance to the relationship at the centre of the film. Ah well. Some scripts just need a little something to hit the emotional high notes.

What drugs can do very efficiently is reduce life to an endless scratchy hunt for a fix. Admirable cinema has been made from exactly that – Lenny Abrahamson’s flawless Dublin tragicomedy Adam & Paul saw heroin addiction as one long frantic non-event interrupted only by bleak sudden ends.

But frantic non-events and bleak sudden ends are unpopular at the box office, and junkies don’t make great heroes. For American cinema, the answer came with scripts that subtly upped the chances of redemption – and a very specific approach to casting. In July 1971, a month after Nixon called drug abuse America’s “public enemy number one”, 20th Century Fox released The Panic in Needle Park, a snapshot of Manhattan addicts that gave its grimy verité an exciting new face – Al Pacino, in his first starring role. He had the charisma of Sinatra with the tang of the counterculture, the addict as pop idol. (The film-makers had originally planned to cast Jim Morrison, singer of the Doors, dead by the time the movie was released.)

The persona went mainstream. Fuelled by the rhetoric coming out of the White House, a drug habit soon passed as youthful rebellion, a death wish middle finger to the straight world. Eventually, that filtered down into a new generation of film-makers smitten with the scuzz of junkiedom. Matt Dillon, last seen as the serial killer of Lars von Trier’s The House That Jack Built, was a Hollywood cover star when he played the rogueish anti-hero of Drugstore Cowboy. In the first boyish flush of his celebrity, Leonardo DiCaprio starred in The Basketball Diaries as underground writer Jim Carroll, forced on to the streets by his teenage dance with heroin. It was a stellar performance – young, damned and about to star in Titanic.

And yes, you’re right – these were all men. Occasionally, a woman was allowed along for the ride (Germany produced the stark Christiane F), but generally drugs on screen were declared a man’s game. A particular kind of man too. After Pacino, Dillon and DiCaprio – and we can throw in Gary Oldman in Sid and Nancy – a string of creatively ambitious pin-ups were cast as users. Jared Leto starred in the operatic Requiem for a Dream; Ryan Gosling played a crack-addicted school teacher in Half Nelson. Now there is Chalamet. The message was remarkably consistent: drugs might lay waste to male American beauty but my God, there will be some acting first.

You’re right again – they were white men too. Even as crack engulfed US inner cities, big-ticket dramas of drug abuse found black and Latino faces seen, if they were seen at all, only as dealers. That queasy dynamic lives on. Amid the dated racial politics of comedy-drama The Upside, currently top of the US box office, we find Kevin Hart bringing the joy of weed to white Park Avenue society.

And then there is The Mule, in which a Mexican cartel sends forth bundles of cocaine from El Paso. While students of the politics of Clint Eastwood might have expected such an intervention in the days of the presidential wall, a surprise may await. In the oddly mercurial way of Eastwood, he might actually have made a film that debunks Trump more brutally than the commentators quietly pointing out that most drugs enter the US in legal border crossings. In The Mule, however the powder gets into the country, it is then distributed by an American – as played by Clint Eastwood, with all the attendant cultural baggage. His whiteness is the centre of the story, allowing him the freedom from suspicion prized by the cartel (a point given an exclamation mark with the racial profiling of an innocent Hispanic driver). The same goes for his age. A war veteran wilfully helping destroy American lives? You might almost call it subversive.

Rather than another film about a beautiful boy on self-destruct, The Mule is a film about an old man seduced by the other side of the transaction. We can surely all see a little of ourselves in that. It can’t be coincidence that two of the most essential series in modern television, The Wire and Breaking Bad, were panoramas of the drug trade as viewed by the dealers. Most of us are in it for the money now, moving parts making profits, the ethics best not dwelled on.

Anyway, the more things stay the same, the more they change. The Nic Sheff of 2019 would probably no longer be in the market for meth. America has now embraced fentanyl and Xanax, the pain and anxiety medications implicated in untold dependencies and deaths. If the movies wanted to catch up with the story, they might find some interesting characters waiting – the likes of Richard Sackler, the pharmaceutical billionaire being sued for his role in creating the opioid crisis, recently revealed to have also patented a treatment for opioid addiction. If that sounds like a plot point to you, it does to me too. Let’s see if anyone calls: “Action”.