Oranges aren't always orange, they're blue - at least that's the conclusion of Christopher, the hapless psychiatric case in Kathy Burke's powerful revival of Blue Orange.

Jo Penhall's drama, which originally made its name in the West End five years ago, has been revived for the first time and arrives in Brighton this week.

Mental illness, race and the ailing NHS are at the centre of this stinging satire, which promises to be as hard-hitting as it is humorous under Burke's direction.

The story stars Roger Lloyd Pack as Dr Smith, a puffed-up senior consultant, and his earnest but inexperienced sidekick, Dr Bruce Flaherty, played by Shaun Evans.

Set in a psychiatric hospital, the action takes place over 24 hours during which a young black man, Christopher is being assessed by Dr Flaherty.

Prior to discharge, Christopher claims to be the son of an exiled African dictator. Dr Flaherty suspects he is suffering from schizophrenia but when he calls in Dr Smith for a second opinion, the conflict escalates in response to Christopher's unnervingly plausible story.

Tension builds as the three characters race through a minefield of arguments, with professional ethics, job prospects and the confusion between racial prejudice and acquired political correctness at the core.

Jimmy Akingbola, who plays the part of Christopher, says: "When I first read it I just thought it was a fantastic piece of writing - it really shook me and I thought this is the type of work you want to be doing as an actor.

"These are great subjects to tackle and I hope it will open people's eyes to how difficult it is to diagnose a patient with a mental illness."

Burke draws on some of the talent which gained her recognition for her award-winning performance in Nil By Mouth.

Her interpretation of Blue Orange is darker and more gritty than the original and is expected to hit the audience head-on.

"Everyone thinks of Kathy Burke as a comedian but she had her ideas about this straight from the beginning," says Akingbola. People laugh and then they stop and they think, 'What am I laughing about?'. It's one of those plays where you leave the theatre and you're still processing what you have seen."

The play also raises questions about language and manipulation, class and power.

The word "nigger" is bandied about the stage, with issues about its usage and ownership brought into question as power shifts between the characters. To gauge a better understanding of mental illness and to pull off the part convincingly, Akingbola visited a real psychiatric hospital and spoke to some of the patients.

"It confirmed to me how accurate the play is in terms of what the doctors say and what the patients go through," he says. "There is so much room to play with this character and push it as far as I can. I try to make it true because it's such an interesting and sad debate.

"This is the most difficult role I have ever played and it's the biggest. I am hoping it will be a turning point in my career. It's definitely the best production I've ever been in."

Starts 7.45pm, Thur and Sat mats 2.30pm, Tickets £15-£24, Tel 08700 606 650