By Mike Fleeman

04/09/2013 at 07:25 PM EDT

Lindsay Lohan and David Letterman

Jeffrey R. Staab/CBS

Lindsay Lohan wouldn’t say what troubles drove her to rehab or what kind of treatment she’ll receive, but the actress insists she welcomes the experience, even if it is The Late Show with David Letterman.

“I think this is an opportunity for me to focus on what I love in life. And I don’t think it’s a bad thing. I think it’s a blessing.”

Lohan, 26, escaped a jail sentence last month when she reached a plea agreement in a lying-to-police case that calls for three months in a locked-down rehab facility, starting May 2.

Appearing on Letterman to promote the film Scary Movie V and the TV show Anger Management, Lohan got a warm reception from the audience despite a couple of awkward moments when she bristled at Letterman’s questions or simply refused to answer them.

When Letterman asked, “How many times have you been in rehab?” the obviously uncomfortable Lohan answered only, “Several.”

“And how will this time be different?” he continued. “What are they rehabbing, first of all? What is on their list? What are they going to work on when you walk through the door?”

“We didn’t discuss this in the pre-interview,” she answered. “I’m just saying to everyone.”

Later Letterman asked, “Now, do you have addiction problems?”

“Now you sound like Dr. Phil,” she said, but Letterman pressed on.

“Yeah, I’m sorry,” he said. “Is it, like, alcohol? Do you drink too much?”

“We’ve discussed this in the past,” she said.

“Did we really?” Letterman responded. “When did we discuss?”

He then joked, “Now I’m the one who’s having the blackouts. I oughta be at rehab. For the love of God, what is wrong with me?”