Bedlam, Shakespeare's Globe, London

Unbalanced tale doesn't lose the plot

At the original Globe Theatre, women weren't even allowed to act, let alone write the plays. And since its reincarnation in 1997, the new work programmed at the Bankside venue has all been by men. Four centuries of male monopoly are brought to an end now by Nell Leyshon and the premiere of Bedlam, an extravaganza that is set in a fictionalised version of Bethlem Hospital, the infamous insane asylum, in the middle of the 18th century.

Leyshon has previously been noted for delicately devastating small-scale pieces. With Bedlam, though, she goes for broke in the opposite direction, turning the Globe into a chaotic madhouse and filling it with slapstick energy and blackly gleeful exuberance. Indeed, the distressing (and conscientiously well-researched) material has been tailored almost to a fault to the theatre's unique environment. Watching Jessica Swale's rambunctious production, which is ebulliently performed by a delightful company, I was frequently assailed by a sense of incongruity: a play that deals with the inhumane treatment of the mentally ill is in constant danger of lapsing into an upbeat crowd-pleaser.

A case in point is the moment when a groundling (who looked to be a plant on press night) is dragged onstage and jokily threatened with a battery of the barbaric cures – leeches, laxatives, and bloodletting – that we have just seen inflicted on the patients at the asylum. It's pure genial pantomime and produces not a flicker of discomfort. Nor as spectators are we ever made to feel in a queasy kinship with the callous, voyeuristic visitors who cough up their penny to gawp at the inmates and poke at them with their sticks.

At the centre of the piece, there's a serious clash of philosophies. The asylum is run by Dr Carew (Jason Baughan), a corrupt, hard-drinking lecher who presides over a one-size-fits-all regime of cruel containment. He's challenged by the more enlightened newcomer, Dr Maynard (Phil Cheadle), who argues that you have to distinguish between the congenitally insane and people with temporary bouts of madness, caused by stress, who can respond to sensitive care.

The gin-sodden Hogarthian background is beautifully conveyed, with interludes in which we witness a band of former bedlamites earning their living on the London streets by singing (superb renditions of) wistful ballads and bawdy drinking songs of the period. But the debate about kinds of treatment is mostly worked out through a tangled plot that descends into a saucy, farcical sex-romp as various unsuitable males – including a foppish, misogynist poetaster (a hilarious Sam Crane) and a reliably ever-randy patient – vie to get their grubby paws on the russet-maned May (Rose Leslie), a lovely young farm girl who lost her wits when her lover was sent to sea.

With guards who are all too ready to be bribed, these shenanigans should underline the rottenness of a system that economically depended on exposing the vulnerable to the outside public. But the determined, high-spirited foolery has a sanitising, feelgood effect. As with the contents of those bedpans that are cheerily emptied over the punters in the yard, you can't quite believe that any of this is real.

To 1 October (020-7401 9919)