InThe Positive Hour, a new play by April de Angelis at the Hampstead Theatre, a social worker organises sessions where you sit round in a semi-circle and talk about what you really feel. There are all sorts of things, it emerges, to sit in semi-circles and worry about: gender, empowerment, sisterhood, single-parenthood, marriage, prostitution and sado-masochism. In Max Stafford-Clark's production of The Positive Hour, we are brought face to face with relevant issues about the modern female experience. This isn't quite the same thing as watching a play.

The sincere social worker Miranda (Margot Leicester) is a perfectly nice woman, and it's not her fault - merely deformation professionnel - that she has to talk about "creative positive change", "longer-term processes" and "working on your situation". But as a central character, she's no Blanche Dubois. To counter this, de Angelis fills Miranda's office with some livelier case studies. Take a deep breath, then, and we'll meet the four participants in The Positive Hour.

Tough-talking Paula (Julia Lane) is a single mother who's lost custody of her daughte, because her boyfriend is violent. Paula earns extra cash giving blow jobs. Low-key Nicola (Kate Ashfield) is a spectacled, book- hugging student, whose mother has died of cancer, and whose melancholy father can't bear her leaving the house. Nicola is going to be a social worker. Wired-up Emma (Patti Love) is a failed artist who wants to produce greetings cards. She is seeing a kinky banker (David Sibley), who likes to relax at home by wearing a rubber hood with straps ("total enclosure"). Emma is also having a mid-life crisis. Finally, Miranda is recovering from some unspecified illness, and has a weak-willed academic husband, the pedantically rational Roger (Robin Soans), who's writing a book on Hegel, and goes on an outbound weekend to rediscover his masculinity. How will Miranda feel when she gets home and finds her semi-naked husband in bondage?

We barely find out. Nor, when Paula cuts her arm with a razor-blade, does the scene unfold in a way that is - at the lowest level - informative. Watching The Positive Hour is like flicking through a mail-order catalogue and finding all sorts of contemporary anxieties which might be well worth acquiring. The thing you don't want to be stuck with is the catalogue itself.

In the 1980s, the more pompous alternative comedians used to talk about something called "recognition comedy", whereby the audience would laugh because they had experienced exactly what the comedian was describing. Women on the Verge of HRT, a new hit comedy by Marie Jones, takes recognition comedy to the point where it might be better described as "niche marketing".

Women on the Verge of HRT introduces us to the cult of Daniel O'Donnell. For those who have never heard of the Irish singer and still want to see the show (an unlikely combination, perhaps), the play opens, healthily enough, with a short sequence of filmed interviews with his fans. They testify to his charm, warmth and rare ability to recognise them in the street and not hurry past. O'Donnell is a man who makes a particular kind of woman feel better about herself.

We meet two fans in a chintzy hotel room after an O'Donnell concert in Donegal. Vera (Marie Jones, the author) has a nice blonde hairdo and wears a silky nightdress, Anna (Eileen Pollock) has a plain haircut and wears crumpled pyjamas. Jones's amiable confessional comedy sets itself up as a straight play, and then in an unashamedly populist fashion, ignores the genre, and breaks into song. A West End theatre like the Vaudeville looks improbably strait-laced for this crowd-pleasing entertainment, which still smacks of pub theatre. The confessions and shared intimacies that follow rely heavily on the potency of a single taboo: the news that women of a certain age still like sex. Here a certain section of the audience on the first night (yes, they did tend to be women) rocked with laughter. I had the impression of being at a convention.

The Chilean playwright Ariel Dorfman achieved international fame with Death and the Maiden, his masterly political drama about a tortured woman confronting her torturer. Before that success, Dorfman had written Widows, a political allegory centred on the image of women retrieving dead bodies from a river. Widows was a poem, then a novel, then an unfinished play. Tony Kushner collaborated on the script (before the success of his own Angels in America). This week Widows received its European premiere. If it isn't as good as Death and the Maiden, it is still a remarkable attempt to dramatise in a semi-mythical way the consequences of recent appalling abuses of human rights.

It's a hard act to pull off. The setting remains deliberately unspecific. Ian Brown's reverential Traverse Theatre production has a spartan disregard for local atmospheric scene setting. The black-clothed widows, who lift these withered skeletal corpses out of the river, act as a chorus as well as individuals. At times, the seriousness of the subject-matter threatens to outweigh the drama. But as Widows develops, Dorfman's themes - the peculiar hell of not knowing what has happened to a relative; the vital link between communities of the living and the dead - find a powerful human context in the triangular struggle between the captain (Sean Scanlan), the younger ruthless lieutenant (Michael Nardone) and the unbending grandmother Sofia (Edith Macarthur). In Ian Brown's fine Scottish cast these three stand out.

Last year's Birdy, an adaptation of William Wharton's novel by the youngish American Naomi Wallace, now reaches the West End, thanks to the new and not very rewarding casting of Northern Exposure's Rob Morrow in the role of Sergeant Al. As his friend Birdy, Matthew Wait is painfully effective, twitching his face and flapping his hands. But Kevin Knight's production is still design-heavy (the stage is dominated by one tilting revolve inside another) and Wallace's adaptation, which cuts constantly between childhood and adulthood, never stays anywhere quite long enough.

Theatre details: Going Out, page 14.