Later this month, a new drama series about a group of gay men starts on Channel 4.

It is hardly ground-breaking because Russell T Davies, its creator, wrote a drama series about a group of gay men for Channel 4 16 years ago called Queer as Folk. But by being good and inventive and funny, what Davies' new series does highlight is how bad, in general, the portrayal of gay men and women on television, radio and film still is. It is almost as bad as it ever was.

There have been some improvements in recent years - most of the soap operas, for example (even The Archers) now have a leading gay character, but what is remarkable is how often gay characters on television stick to the stereotypes. The American comedy Modern Family, for example, has been seen by some as progressive in its portrayal of two gay dads, but much of their behaviour and conversation sticks to the tiresome old stereotypes.

The stereotypes generally fall into two main categories: the bitchy queen and the doomed victim, the first being more persistent than the second. In 2013, Ian McKellen and Derek Jacobi starred in a sit-com called Vicious, which relied almost entirely on the bitchy, vicious queen cliché and, while it was funny in places and was created and written by gay men, it did little to promote the idea that gay people live on the same spectrum as straight people: the spectrum from conservative to liberal, funny to unfunny, vicious to kind.

As for the doomed victim stereotype, it is less common these days, although by no means unusual. Up until at least the 1980s, the rule in television and film was that all gay people had to suffer, or ideally die, by the final scene, as a kind of punishment for their difference. It happened in films like The Children's Hour, which stars Shirley MacLaine as a lesbian tormented by her sexuality, or Suddenly Last Summer, in which a gay man is cannibalised by a vengeful gang.

Even now, a gay character in film or television is more likely to be troubled than happy; in the Channel 4 soap Hollyoaks for example, the gay character Steven is usually seen sobbing uncontrollably in between bouts of taking drugs and being beaten up. And while The Imitation Game, the recent movie about the mathematician Alan Turing, was undoubtedly a story that needed be told to modern audiences, it was, once again, the story of a gay man who is troubled and kills himself.

All of these gay stereotypes do have a place, in that gay people do sometimes suffer and are sometimes witty and bitchy, but what made Russell T Davies' Queer as Folk so extraordinary when it was broadcast in 1999 was that it featured a range of realistic gay characters who weren't ruled by the fact they were gay; they just happened to be so. That's what made it so enjoyable.

Davies is essentially repeating the trick with the new series, which is called Cucumber, and that is both encouraging and depressing. What's encouraging is the fact that with Cucumber, there has been none of the tabloid shock and horror that greeted Queer as Folk. What's depressing is the fact that characters like the ones in Cucumber are still much less common that the old stereotypes that refuse to die.

Cucumber begins on January 22 at 9pm on Channel 4.