You will have heard by now that Steven Soderbergh has announced his departure from filmmaking. His farewell dish for cinema, Side Effects, was released last Friday. And there’s still the tantalising final course to come - we’ll see whether it will amount to dessert, cheeseboard or wafer-thin mint- in the shape of his forthcoming HBO Liberace biopic, Behind the Candelabra, which airs in the US at the end of this month. It certainly has genius casting on its side, as this image proves: Michael Douglas is an unbeatable choice for the shy-and-retiring, discreetly-costumed pianist, while Matt Damon plays his lover Scott Thorson (on whose memoir Richard LaGravenese’s screenplay is based).

As Soderbergh has made clear, he is only retiring from cinema: “But I still plan to direct - theatre stuff, and I’d do a TV series if something great were to come along.” In this brilliant, fascinating interview from Vulture.com, he elaborates on his decision:

“These things - I can feel them coming on. I can feel it when I need to slough off one skin and grow another. So that’s when I started thinking, All right, when I turn 50, I’d like to be done. I knew that in order to stop, I couldn’t keep it a secret - so many things are coming at you when you’re making films that you need to have a reason to be saying no all the time… It’s a combination of wanting a change personally and of feeling like I’ve hit a wall in my development that I don’t know how to break through. The tyranny of narrative is beginning to frustrate me, or at least narrative as we’re currently defining it. I’m convinced there’s a new grammar out there somewhere… If I’m going to solve this issue, it means annihilating everything that came before and starting from scratch. That means I have to go away, and I don’t know how long it’s going to take. And I also know you can’t force it. I love and respect filmmaking too much to continue to do it while feeling I’m running in place. That’s not a good feeling. And if it turns out I don’t make another one, I’m really happy with this last group of movies. I don’t want to be one of those people about whom people say, ‘Wow, he kind of fell off there at the end.’ That would be depressing.”

Side Effects is certainly no disgrace: swansong or not, it’s a dynamic and engaged piece of entertainment. It stars Rooney Mara as a dazed woman whose husband (Channing Tatum) has just finished a prison sentence for insider trading: as she adjusts to having him in her life again, she starts to experience symptoms of depression, and turns for comfort to a new drug prescribed by her psychiatrist (Jude Law). That’s all I’m going to say about the plot - it was a joy to see the picture without having read anything in advance about it, and without any prior knowledge of the direction in which it might be travelling. But it’s giving nothing away to sing the praises of its woozy cinematography, crisp and disorienting sound design, and precision editing; the atmosphere of incipient panic calls to mind nothing less than Rosemary’s Baby, even if the pleasures and mysteries of Side Effects are finite, rather than continually expanding as in Polanski’s film.

I liked Side Effects a lot: that is, I enjoyed it while it was underway, it left no lasting impression on me and I would be surprised if it yielded any fresh pleasures on subsequent viewings. But as a mildly twisted thriller which has an instant emotional effect on the audience, it’s a blast. It is especially encouraging to witness Soderbergh’s encouraging way with actors, none more so than Catherine Zeta-Jones. Again, I don’t want to say too much about her role in Side Effects, but she certainly relishes the things she has to do (even if she doesn’t get to do quite enough of them to excuse the rather simplistic journey taken by her character - ah, you’ll see what I mean).

It’s been good having Soderbergh around: he’s an energising force, keen to turn cinema into a charged discussion of ideas, and ruthlessly self-critical. (Asked by Vulture what people might people mean when they call a film Soderberghian, he replies: “I have no idea. But never use that word to describe your movie in a pitch meeting because it won’t get made.”) When he accepted the Palme d’Or in 1989 for his debut Sex, Lies and Videotape, he famously told the audience: “It’s all downhill from here.” He didn’t get it quite right. A corkscrew rollercoaster would have provided a better analogy. His commercial fortunes diminished with each film he made after his Cannes win, until Out of Sight arrested the decline in 1998. The double-whammy of Erin Brockovich and Traffic made it a distant memory. He has squeezed more creative and artistic peaks and troughs into the years since Traffic won him the Oscar for best director than most film-makers manage in an entire career. The Good German, Ocean’s Thirteen? Trough time. Che, Magic Mike, Side Effects? Peak.

After hitting the buffers with his 1995 thriller The Underneath, he purged himself with the free-form Schizopolis, one of the most masochistic works ever committed to film: a portrait of mental, marital and artistic breakdown in which Soderbergh cast himself and his real-life spouse from whom he was separating acrimoniously. After that picture, which he now describes as a “rebirth,” he felt free to reinvent himself with Out of Sight. That was crucial in kick-starting the second, most fruitful phase of Soderbergh’s career, and in bringing him together with George Clooney, later to become his semi-regular leading man and co-founder of their (now disbanded) production company, Section Eight.

Even once Soderbergh was back on track with confident, playful work like Out of Sight and The Limey, he was not one to parrot the party line on the enchanted world of film-making. Do grab the DVDs of both those films if you can: the commentary tracks feature sustained and often bitter arguments between Soderbergh and his respective screenwriters, who berate him for every perceived distortion or compromise. “I get sick of everyone saying everything’s great all the time,” he once said. “I like to hear about the blood and gristle of the creative process. I hate these fucking interviews where it’s like there’s sunshine shooting out of the director’s mouth. So I try to be very careful about the syntax I employ. I don’t want to suggest, ‘We’ve done an amazing thing here.’” Generally, he’s in favour of letting history decide. “All my pleasure is in making movies,” he said in 2007. “Twenty years from now we'll figure out which ones are great and which ones aren't.” Even those who believe Soderbergh is mad to withdraw from cinema will recognise that as the voice of sanity.

"Side Effects" is on release.