As part of its 40th anniversary celebrations, Chickenshed is reviving a selection of its watershed productions. Among them is Paula's Story, first performed in 1993, and still featuring one of the original cast, Louise Perry, as Jan.

It's an inspirational, real-life drama that brings unsettling truths to light, with director Mary Ward's script written from transcripted conversations with the Rees family.

When Jan and Eddie Rees have a second child, Paula, she doesn't seem to behave quite like other babies. Jan persists in asking the doctor to investigate further, despite being labelled a neurotic mum.

Eventually baby Paula is diagnosed with cerebral palsy. It's shocking to realise that even in the 1970s, the recommended course of action was to park a child like Paula in an institution – padded cells and all – and forget about her.

But the Rees family is made of sterner stuff. With Jan's determination, Eddie's support, and Paula's own extraordinary heart and spirit, she lives through endless prejudice and terrifying surgery to emerge as an inspirational poet and lyricist. The play asks its audience to question our own responses to disability and ‘otherness', and Paula herself is on stage to oversee the production, looking back on her own life being played out by a fine cast.

Louise Perry is simply outstanding as Jan, communicating all this passionate mother's quiet determination, backed by fierce loyalty and a refusal to accept spurious ‘expert' assessments as she fights for Paula's health and education.

Dad Eddie is played with steadfast truth by Iain Whitmore, who captures the mix of bewilderment and love that propels him to ensure his family stays together.

Lauren Cambridge is also powerful as Kerry, Paula's older sister, whose own needs are often – inevitably – overlooked. Cambridge manages the contrasts between teen rebel and loving sister with a delicately balanced performance.

And Kyle Rees-Blackstone, Paula's real life nephew, brings the family to the heart of the stage as little brother Ian.

Music has been an important part of Paula's life since her involvement with Chickenshed began, and her lyrics have been combined with tender tunes, played and sung by Jo Collins. These songs punctuate the action to great effect, and stir palpable emotion as they express so poignantly what Paula cannot say aloud.

Chickenshed has achieved many great things in the last 40 years. Its inclusive ethos has changed the lives of hundreds of young people who might otherwise never get a chance to prove they can make great drama.

Paula Rees has proved that anything is possible, and no one should be underestimated. She's one of Chickenshed's finest.

Paula's Story runs at the Chickenshed until 17 May