Channel 4 has commissioned what it is labelling an "audacious new comedy series" focusing on a character with bipolar disorder.

Written and created by Camilla Whitehill, Big Mood is described as "a vivacious and rebellious portrayal of female friendship when infiltrated by the complexities of a serious mental illness."

The six-part series will explore "the messy pitfalls and idiosyncrasies of navigating adulthood through wicked humour, daft anecdotes, and unsettling truths."

The episodes will focus on best friends Maggie and Eddie, played by Derry Girls star Nicola Coughlan and It's A Sin actor Lydia West. The comedy is inspired by Coughlan's own real-life relationship with the programme's writer.

The characters in the show have lived in each other's pockets for ten years, through thick, thin, and "multiple challenging eyebrow trends". Talking about the plot, Channel 4 says: "But with the rest of their lives looming, careers hanging in the balance, and Maggie's bipolar disorder making an unwelcome return to form, Eddie begins to question whether this friendship is really in their best interests. It's a pivotal point in both their lives, bringing to the surface those all-important questions - could sleeping with your former History teacher be the key to happiness? Is a basement 'rat hotel' a functional alternative to pest control? How do you stop your new psychiatrist giving you worry dolls? With their twenties behind them, Maggie and Eddie's relationship faces the future - can it survive?"

Nicola Coughlan says: "When I first met Camilla Whitehill long, long ago, during the time of Indie Sleaze, I quickly realised she was one of the funniest and most talented people I'd ever met. It was always our dream for us to work on something together, and now Channel 4 are making that dream come true. I can't wait to make this show with this amazing group of people."

Lydia West adds: "I'm so happy to be working with Camilla and Nicola on this project. The writing is genius, and the subject explores the mental health struggles that all of our generation face - coupled with how to navigate complicated, loving and nuanced friendship. Channel 4 is the perfect home for this heart-warming, hilarious, savvy comedy and I feel truly honoured to tell this story which touched my heart."

Camilla Whitehill comments: "Getting my own Channel 4 comedy still feels like some kind of long form prank, Punk'd style. But on the off chance it isn't, I am beside myself to be making this show with such an incredible team of people, a cast that I'd be jealous of if it wasn't my cast, and for a channel that's produced some of my favourite shows of all time."

Laurence Bowen and Chris Carey from producers Dancing Ledge Productions say: "We've always loved Camilla's writing so producing her first series with Channel 4 is an absolute treat. Her writing is laugh out loud funny because it's truthful and that's what makes her such a star. Add to that two of the best actors in the world, Nicola Coughlan and Lydia West, and one of the finest directors, Rebecca Asher, and we're well and truly made up."

Commissioning editor Laura Riseam concludes: "Big Mood is an authentic portrayal of the passionate, reckless, and surreal tales of close friendship threatened by an all-consuming mental illness. It's outrageously daring, painfully funny and unreservedly poignant - the type of comedy that firmly belongs on Channel 4. We are delighted to welcome Camilla and Dancing Ledge into the fold."