The 21-year-old - Spencer Moon in the soap - has been on extended leave for three weeks. The young actor was hospitalised earlier this month after allegedly slashing his wrists amid speculation over his sexuality.
A BBC spokeswoman said that the decision was reached jointly by Parker and EastEnders producers, adding: "We'd like to thank Chris for all his hard work over the last two years and wish him the best of luck in the future."
Scriptwriters are currently creating a storyline to explain his character's absence from the show.
Parker's final scenes will air in January.
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