Arianna Huffington said she plans to step down as editor-in-chief of the Huffington Post, the politics and news site she founded in 2005, turning her attention to a wellness venture focused on the “global pandemic” of stress and burnout.

Huffington, 66, announced her departure Thursday in a memo to staff of the publication, which was acquired by AOL for $315 million in 2011 and is now part of Verizon Communications Inc.’s media business. She said she had intended to keep running the site, then decided to turn her attention to her startup, Thrive Global, after attracting investors and hiring staff.

“As Thrive Global moved from an idea to a reality, with investors, staff, and offices, it became clear to me that I simply couldn’t do justice to both companies,” Huffington said in a statement.