She was demonstrating "inversion therapy." That's where you hang upside down by a swing. She does it 15 to 30 minutes a day as part of her treatment for depression -- treatment that also includes yoga and antidepressants.
Saying "it looks scary, but it's not," O'Donnell climbed onto the swing, which sent the audience into wild applause.
O'Donnell says she began treatment for depression after the Columbine school shootings. She says, "I stayed in my room. The lights were off. I couldn't get out of bed and that's when I started taking medication."
She says there's no shame in taking anti-depressants, adding "it saved my life."