‘I’m afraid,” says Rose, one of the leading characters in Michael Hastings’s Tom and Viv. She has good reason to be. The behaviour of her daughter — the Viv of the title — is becoming increasingly erratic, while her long-suffering husband, the poet T. S. Eliot, struggles to cope. In fact, fear is prevalent in this moving drama — fear of the unknown, fear of the incomprehensible, Viv’s own fear of her frequent loss of control and what the future holds for her. The play also exposes society’s harsh, uncaring attitude to mental illness, and forces us to confront our own attitude. How would we respond in the same situation?

When the shy, awkward and inexperienced Tom elopes with the feisty Viv, there is an uneasy feeling that the course of this love will run anything but smoothly. Before long Viv’s high spirits begin to emerge as something more troublesome, and her sudden, passionate outbursts become increasingly frequent. The strain soon begins to show, and it is not just Viv’s mental health that seems to be deteriorating; around her, family relationships are also disintegrating. The result is a fascinating and compelling study, with a poignant twist at the end.

In this production by ElevenOne Theatre, director Joe Kenneway has ensured a compassionate and sensitive handling of Viv’s problems and their effect on her family. Helen Taylor is a towering presence as Viv, portraying her mood swings with exceptional clarity; this is a really powerful and moving performance. Brian Earp (pictured with Helen Taylor) is equally impressive as Tom, a man increasingly at the end of his tether as he struggles to understand and cope with his wife’s illness. Lisa Barnett and Nick Quartley give touching performances as Viv’s parents, while Will Fournier provides light relief as her brother, the archetypal upper-class twit, Maurice.

Moser Theatre, Wadham College, until Saturday. For tickets and further information visit the website (www.111theatre.co.uk).