It’s always high-stakes viewing when a book you love is transferred to the screen. The world of the novel, vividly imagined, can feel flat and jarring when it’s beamed into being from another person’s brain. “That’s not how it’s supposed to be,” you think, because although the adored writer has sketched the outlines, someone else has art-directed it, colouring it in – more often than not in the wrong shades.

This is precisely what I worried would happen in the TV adaptation of My Brilliant Friend, the first novel in Elena Ferrante’s fiercely loved and lauded Neapolitan Quartet. How could anyone possibly succeed in translating such a vividly conjured setting and group of characters as the “neighbourhood” and its inhabitants to the screen?

It has all the nuances of the friendships that women know to be such crucial forces in the fabrics of our lives

And yet, they have done it. My Brilliant Friend aired last week on Sky Atlantic. A co-production between HBO and Italy’s Rai Fiction and Timvision, the whole thing is in a mixture of Italian and the Neapolitan dialect spoken in “the neighbourhood”, for which even Italian viewers need subtitles. And it’s brilliant. It succeeds entirely in bringing the world so many readers know to life – which is perhaps as much of a testament to the talents of Ferrante, who acted as consultant, as it is to the producers.

But what struck me most about the shifting of the story into a different medium is the time given to the two main – female – characters, and how revolutionary it still feels to see female friendship explored onscreen in this way. If the portrayal of this friendship was revelatory in the novel, with all that form’s facility for introspection, then on screen it is even more so. It goes without saying that it takes the Bechdel test and turns it into ragù.

It’s 2018, and audiences are more switched on than perhaps ever before to the paucity of female characters. Certainly it wasn’t something that I noticed when I was younger, though in hindsight I was always drawn to depictions of women that were fleshed out as opposed to flesh-fixated. Hollywood’s stock response for many years came in the form of “strong female characters”, a strategy that, critics have pointed out, hardly requires much more imaginative effort.

Ludovica Nasti and Elisa del Genio in the screen adaptation of My Brilliant Friend Photograph: Eduardo Castaldo / Wildside / UMEDIA 2018

As Rachel Weisz said in a recent interview about Disobedience, the film adaptation of Naomi Alderman’s novel about a lesbian affair between two Orthodox Jewish women, which she has produced and in which she stars: “Strong female roles? Such a weird notion. I think what there is … [is] a paucity of roles which are written where the female is the engine of the story and is not peripheral.”

This remains a problem. Not infrequently, while watching a film or a TV series, I start to wonder how long it will take for a woman to appear on screen, or whether there are going to be any women involved at all. It happened with The Alienist. When Dakota Fanning finally appeared on screen I breathed a sigh of relief (apparently her role was expanded “into a fuller portrait of a young woman trying to be tough enough to thrive in a man’s world without losing her femininity and sexuality”, so God knows how scanty it must have been before. Alas, the other woman in the series, played by Q’orianka Kilcher, is mute).

It also happened, sad to say, in the latest Coen brothers movie. It took 41 minutes of The Ballad of Buster Scruggs for a woman to get a line (“Wanna buy your friend some lovin’?”), and it’s spoken by a prostitute, in the background. I love the Coens and the film, and they almost make up for it later on, but I did wonder what on earth was going on.

So it feels incredible, really, to watch My Brilliant Friend and see such a large amount of screen time given to girls talking to one another about Latin and periods and books. The relationship Lenù and Lila have with each other, and not to the men in the story, is the central focus – and that relationship is complicated and fraught and competitive, as well as being intimate and passionate and educative. It has, in short, all the nuances of the friendships that women ourselves know to be such crucial forces in the fabrics of our lives – the ups and downs and ins and outs by which so many men claim to be baffled. Of course they are, because so much of the dynamic can be instinctive and unspoken, not to mention further complicated by existing in a man’s world, as Ferrante so powerfully depicts.

The Neapolitan Quartet is, of course, not the only depiction of female friendship to appear on screen. In fact you could say there is something of a canon, encompassing everything from Thelma & Louise to 2015’s Girlhood, Frances Ha and Broad City, not to mention 1978’s Girlfriends, Our Song, Me Without You and of course, Sex and the City. But where the Quartet and now the TV series differ is in length and scope. This is a depiction of a female friendship, vividly rendered, which lasts a lifetime, from childhood alongside all the other pressures Lenù and Lila face. That still feels transgressive.

As Ferrante wrote in this newspaper, “a relationship between friends has the richness, the complexity, the contradictions, the inconsistencies of love”. I hope male viewers tune in. Not only will they learn a lot, but it’s going to be quite the journey.

• Rhiannon Lucy Cosslett is a Guardian columnist and author