Ellen DeGeneres will end her namesake talk show next year — at the conclusion of its 19th season."The Ellen DeGeneres Show" is currently in production of season 18. DeGeneres will discuss her decision to end the show in an interview with Oprah Winfrey, scheduled to air on Thursday. "When you're a creative person, you constantly need to be challenged – and as great as this show is, and as fun as it is, it's just not a challenge anymore," DeGeneres told The Hollywood Reporter, which first broke the news."You may wonder why I've decided to end after 19 seasons. The truth is, I always trust my instincts. My instinct told me it's time," a tearful DeGeneres said Wednesday during a taping for Thursday's show."I promise you that we're going to have a fantastic final season. It will be a season where I truly get to say, 'Thank You. Thank you all.' Every day will be a celebration," she said.She used humor to lighten the mood and the message."In 1997, I knew it was time to come out on my sitcom and live my truth," DeGeneres said, recalling a vivid, inspiring dream in which a bird escaped its cage because it had to be free."Recently, I had a dream that a bird, beautiful bird with bright red feathers, came to my window and whispered, 'You can still do stuff on Netflix,'" a deadpan DeGeneres said, drawing laughs from the virtual studio audience.Nielsen data shows "Ellen" viewership dropped by 1.1 million people this season, from 2.6 million viewers to 1.5 million viewers.The news comes nearly a year after controversy swelled over toxic workplace allegations. DeGeneres apologized to the show's staff amid an internal company investigation of complaints of a difficult and unfair workplace. Three senior producers were ousted as a result of the investigation."On day one of our show, I told everyone in our first meeting that ‘The Ellen DeGeneres Show’ would be a place of happiness — no one would ever raise their voice, and everyone would be treated with respect," DeGeneres wrote at the time. Something changed, she said, "and for that, I am sorry."In a separate statement, the Warner Bros. studio said the investigation's "primary findings" revealed what it called some flaws in the show’s daily management.DeGeneres' memo and the probe by the studio’s parent company followed a BuzzFeed News report in which one current and 10 former show employees complained about issues including being fired after taking medical or bereavement leave. One worker said she left because of comments about her race. The Associated Press and CNN contributed to this report.