The actress, who plays Tanya Branning, said the depressive storylines are "relentless" and that she needed to do something more lighthearted.
However, Jo - who has faced storylines involving cancer, infidelity and alcoholism - has confirmed that she will not be killed off and that the door has been left open for her to return.
Speaking on ITV1's Loose Women, Jo said: "Burying people alive, getting divorced… There's quite a bit of misery in Walford and quite rightly, understandably, it's a drama.
"[But] for seven years, it can get a little bit relentless. I just need a little break to do something lighter."
Mum-of-two Jo officially announced she was leaving EastEnders in April, but when asked if she was going out "in a coffin or a cab", she confirmed Tanya may one day return.
"It's not a coffin, I can tell you that, and actually it's not with a very big bang. She's got some making up to do with the kids, and I'd say this makes up for it," she added.
Jo was then asked who would be looking after her on-screen children – Lauren, Abi and Oscar.
Remaining tight-lipped, she replied: "I can't tell you these things, who is having all the children. I won't be saying who is coming with me – you'll have to watch."
Jo is now set to star in a new sitcom, called Trying Again, on Sky Living.
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