The British soap opera, "EastEnders" is to give a shocking twist in the storyline for this Christmas, where Stacey Branning is to be diagnosed with a rare mental illness after giving birth to her second child in the upcoming episodes.

Just before Christmas, Stacey in "EastEnders," played by Lacey Turner, will be seen experiencing symptoms of postpartum psychosis, which is an uncommon post-delivery condition, known to be affecting few women after delivery.

Stacey was previously diagnosed with bipolar disorder in 2009. According to Executive producer of "EastEnders," Dominic Treadwell-Collins, Stacey's health condition will be one of the biggest storylines on Christmas and New Year as her bipolar disorder and its effects on her and her near ones will be discovered.

''We have always had a big commitment to Stacey's story and this time we want to explore the effects of postpartum psychosis on those with bipolar - something which, although a rare illness, is unfortunately more common when mothers with bipolar give birth - and look at what we are doing as a country to help mothers experiencing this.'' Dominic said, according to TV3.

The soap opera is aired on BBC One and they have been working in collaboration with the mental health charities Mind and Bipolar- UK, and other experts in the same field. Clare Dolman, who is UK's vice chairwoman for Bipolar and involved in national charity for supporting individuals with bipolar, is really happy to work closely with BBC on Stacey's story.

"There is a very high risk that women with bipolar will become ill when they have a child and 20%-25% of them will have a postpartum psychosis so it's fantastic that "EastEnders" are raising awareness of this devastating condition," said Dolman, as reported by Irish Examiner.

Aired in UK for the first time, on BBC One on February 19th 1985, "EastEnders" is a soap opera based on the domestic and professional lives of people who live in a fictional place called London Borough of Walford in the East End of London.