Discovery Communications President and CEO Judith McHale announced Tuesday she will step down Dec. 1 to get involved in politics.

In a joint statement with Discovery founder and Chairman John Hendricks, Ms. McHale described her “decidedly mixed emotions” about leaving the company after 19 years.

“Today, as a global society, we face enormous social and political challenges,” she wrote. “Throughout my life and career, I have tried to do what I could to confront and understand these issues. Now I want to become more directly involved in working with others to find solutions.”

Ms. McHale said she and Mr. Hendricks concluded “it would not be possible for me to continue in my current role while at the same time actively pursuing these new endeavors.”

If a new CEO is not yet in place by the time Ms. McHale departs, Mr. Hendricks will act as CEO during the interim.