Actress Gwendoline Christie. Picture: Joel C Ryan/Invision/AP

Gwendoline Christie says audiences will "need therapy" after the 'Game of Thrones' finale next year.

The 40-year-old actress stars as Brienne of Tarth in the HBO fantasy drama series, and as the show's eighth and final season prepares to air in April next year, the star has said viewers are in for a shock so big they'll need to seek "professional help".

She said: "You're going to need therapy. I think just the show ending is going to send all of the world into professional help."

Gwendoline also believes the show's finale will be "incredibly emotional", especially for the cast, as she says the programme has been a "truly incredible thing" to be involved with.

She told E! News: "I think it's going to make me incredibly emotional. We're all emotional about the fact that this is the end, and this is the end of something incredibly significant for all of us, and it's been a truly incredible thing to be a part of." 

The actress' comments come after it was confirmed last month that 'Game of Thrones' would be returning to screens in April 2019, when a 30-second teaser clip was posted to the show's official Twitter account.

The clip featured action-filled shots of various stars of the show, including Daenerys Targaryen (Emilia Clarke), Jon Snow (Kit Harington), Cersei Lannister (Lena Headey), Sansa Stark (Sophie Turner), and Tyrion Lannister (Peter Dinklage).

Fans of the show have a lot to look forward to for the upcoming finale, as Emilia Clarke recently revealed "everything" from the costumes to the camera checks have been "more intense" than ever before.

She said: "[Camera] checks take longer, costumes are a bit better, hair and makeup a bit sharper - every choice, every conversation, every attitude, has this air of 'this is it.' Everything feels more intense."