After losing her friend Danielle Jones, Stacey began acting strangely in May 2009, and the character has to come to terms with the prospect that, like her mother, she also suffers from bipolar disorder. The storyline was developed as of the BBC’s Headroom campaign, which aims to encourage people to look after their mental wellbeing.Series Consultant Simon Ashdown had been developing the storyline for about a year. To accurately reflect the issue, EastEnders worked closely with various charities such as Mind and MDF The BiPolar Organisation, medical practitioners and bipolar sufferers when researching the storyline.

The story was moulded around what Stacey would do in that situation and what the research led the team to believe was the most truthful way events would develop.

Executive producer Diederick Santer said that the initial buildup of the storyline was an extension of how the character has always been, “a character of highs and lows, of great passions and dark moods,”[ut these highs and lows would become more contrasted, and viewers would realise that Stacey's mood is more complex than just being upset over her losses, adding, "It's the beginning of us getting to really know and understand who Stacey is and what makes her behave the way she does." Turner hoped that she could do the storyline justice, saying that she believed it was great that EastEnders continued to raise awareness of the issue.