CLERGY wives have proved rich inspiration for dramatists. Our great chronicler of the suburban and provincial, Alan Ayckbourn, made his contribution with Woman in Mind in 1985. Forty years on from its Scarborough première, a new revival stars Sheridan Smith as Susan, the downtrodden vicarage spouse.

This show belongs to Smith. All the action takes place in the garden, and she does not leave the stage once. Possibly the most talented comic actor of her generation, Smith mines full dramatic colour with just a finger move or head-toss. It is a tricky play, because she has to portray with comedy and pathos someone in the grip of isolation and psychosis. Ayckbourn’s skill is in showing how such episodes are only a couple of beats away, and how terrifying that is.

The first scene has Susan coming-to on the lawn, apparently speaking in tongues, with a head injury from stepping on a rake. The local GP (another community comic staple) arrives to assess her. Romesh Ranganathan as the clumsy doctor plays it dumb. The situation is as hapless as it is hopeless.

Throw into this the vicar, Gerald — given a fulsome and rounded portrayal by Tim McMullan — who is uncaring and obsessed with writing the parish history “from 1386”. His widowed sister, Muriel (Louise Brealey), is living with them; scatty and neurotic, she cooks indigestible meals and keeps having visions of her dead husband. The vicarage son has been absent these past two years at a “sect” in Hemel Hempstead where he could not speak to his parents. His sudden return is eagerly awaited.

To complicate matters, Susan keeps lapsing into reveries with an alternative family, a mirror-opposite of the other characters. There are her daughter, Lucy (Safia Oakley-Green), husband, Andy (Sule Rimi), and brother, Tony (Chris Jenks). They burst on at opportune moments in a palette of ice-cream-colour clothes. But the vicarage family cannot see them, and Susan seems happier in this Wonderland life.

Rick (an assured Taylor Uttley), the “real” son, appears at the end of the first half to fetch his mother in from the garden; having left the cult, he now brings a lot of news. The second half has a storm, a fire, family revelations, and a dream sequence. For Rick, his mother is a monster and too interested in sex. She is also difficult for the others. Faith has no answers, even when the priest is “a specialist in matters unseen”. Who would live in vicarage like this? By the end, Susan is on her own again, whispering words into the dark.

Four decades ago, mental health was not much spoken of. Women — and it was usually women — were condescendingly referred to as living “on their nerves”, “on tablets”, or some other euphemism. There was a lack of support and even lower understanding. That may have improved, but it still makes for uncomfortable viewing, as Ayckbourn and the creative team demonstrate.

Directed by Michael Longhurst, designed by Soutra Gilmour, and lit by Lee Curran, this strong ensemble piece largely stands the test of time. Sheridan Smith is fantastic. She has referred to “my own mental crisis” before and brings that experience to bear. For the audience, it is unforgettable.

At the Duke of York’s Theatre, St Martin’s Lane, London WC2, until 28 February. The play tours to the Sunderland Empire (4-7 March) and Theatre Royal Glasgow (10-14 March). womaninmindplay.com