Sharon descends on Walford next week as she needs Phil Mitchell's help after walking out of her own wedding, leaving her young son Dennis behind. Viewers will later see her decide to stick around in the area for good.
Speaking in a pre-recorded Daybreak interview broadcast today (August 10), Dean explained that Sharon will be at rock bottom in her return episodes.
Pictured: Letitia Dean chats to Daybreak on set at the Queen Vic.
Asked whether the show favourite has an ulterior motive, Dean replied: "No, she's totally lost. She doesn't know who she is, where she's going. There's something that comes out later, that's happened to her in the States and stuff like that.
"But she's a lost soul, and this is home again. There's no place like home, so she finds herself back there again."
Speaking of reprising the role of Sharon, she continued: "It's just wonderful to be back. It is that old cliché - there is no place like home, and it's always felt like that to me. It's joyous to come back as a mother - a little more mature."
Dean added that she is looking forward to seeing what the future could hold for Sharon and Phil (Steve McFadden).
She said: "I've always loved working with Steve - I think he's fantastic. I think there's always going to be that frisson between Phil and Sharon. I don't know where it's going to go - I'm not quite sure yet. But I'm sure it'll be fantastic."
The 44-year-old also reiterated her desire to stick around on EastEnders for a long while.
Asked whether Sharon is staying for the foreseeable future, she replied: "Well, I hope so - it depends if they want to keep me, really. But it's really lovely for me to come back, and quite an honour to be asked again for the third time."
EastEnders airs Sharon's return episodes on Monday, August 13 at 8pm and 9pm on BBC One. Get the Inside Soap magazine on your iPhone or iPad