CHICAGO — There’s a major music festival taking place, but for some it’s the International O.C.D. Foundation’s annual conference that brought them to Chicago this weekend.

The symptoms can be debilitating: compulsive checking, cleaning and reassurance seeking. The anxiety is so powerful it keeps some from leaving the house. But therapists are asking them to go on stage instead.

Believe it or not, it helps.

It’s all improv. Performers team up with O.C.D. sufferers at Second City in a workshop that puts the spotlight on anxiety.

“The nice thing about improv is it’s immersive,” said Piero Procaccini, a Second City improv teacher. “You’re not just talking about the principle, you’re doing it; you’re putting it into action.”

Performing has helped Ethan Smith overcome the extreme anxiety he’s felt since he was a little boy.

“I think just being able to get on stage, and even just for a moment getting out of your head and getting out of that fear… gives you that little glimpse of hope,” Smith said.

More than 1600 people are expected to attend this weekend’s conference, and registration is still open.  The improv exercises there are designed to foster collaboration and build confidence.

“If there is any constant in life it’s that life will continue to change whether you want it to or not, and I think improv is very similar,” said participant Nathaniel Van Kirk. “You never know what’s coming at you next.”

Second City also offers programs for those with autism, Parkinson’s disease, and even a class for seniors throughout the year.