E20 returned for its third series on Tuesday and will play out online and on BBC Three over the next five weeks, focusing on three young characters who hide out together on Albert Square.
Colquhoun, who plays runaway Ava Bourne on the show, told Digital Spy: "It's very different this year as it's taken a very different tone. It's very gritty, it's a lot more real, it's a lot more dramatic, a lot more sensitive, and I think it's addressing issues that are very prevalent today.
"Although a lot of these issues are regularly pointed at in drama, they're never actually discussed and that's what we're pushing to do in this series. We want to say that these things are happening, they're not going away and we should talk about it."
E20's new run has been developed in conjunction with BBC Learning, meaning that the storylines will be used in schools to create discussion in PSHE lessons.
Colquhoun added: "I think that's so important for young people and it's incredible that E20 is going into schools this year to actually be discussed. I really hope that people can learn from it, as I know I've learned a lot from doing it."
EastEnders: E20 airs new episodes online every Tuesday, Thursday and Friday. A weekly omnibus can also be seen every Friday night at 8.30pm on BBC Three.
> Read our full interview with EastEnders: E20 star Sophie Colquhoun
> Read all the latest EastEnders: E20 news and spoilers
> Read all the latest EastEnders news and spoilers
Watch the first episode of EastEnders: E20's new series below: