It's the question everyone wants to ask Lindsay Lohan, but only David Letterman is bold enough to do it. The "Late Show" host questioned the troubled actress about her latest legal mess Tuesday, asking her, "Do you have an addiction problem?"

Lohan was in the CBS late night show to promote her new movie, "Scary Movie 5." But instead of talking about the spoof comedy flick, she ended up answering (and dodging) Letterman's blunt questions during the interview.

After they shortly reminisced about Lindsay's first appearance on Letterman's NBC show in 1992, the duo good humouredly talked about sensational tabloid headlines about the 26-year-old actress. The interview changed into a more serious tone when the host asked her if she was supposed to be in rehab, referring to her most recent court sentence.

"Don't you watch anything that goes on?" she countered, before adding, "May 2nd."

When Letterman persisted with more questions about the topic, including how her latest rehab would be different from her previous stints in various centres, she said, "We didn't discuss this in the pre-interview."

She gave in after a short while, admitting that her 3-month shift in rehab is a good thing for her.

"To be honest, I'm the healthiest when I'm working, and the happiest. And I think this is an opportunity for me to focus on what I love in life. I don't think it's a bad thing. I think it's a blessing, not a curse."

But then David continued by asking her if she has an addiction problem, to which she replied, "Now you sound like Dr. Phil."

Lohan was sentenced to a 90-day rehab after she pleaded no contest to misdemeanour charges of reckless driving and providing false information to a police. She was also sentenced to 30 days of community service and 18 months of mandated psychotherapy.

The charges stem from an incident last year when she crashed her car in Santa Monica and lied to the police by telling them that her assistant was driving during the accident.

Though the punishment seems too heavy for the crime, it was actually a bargain. There was a mandatory 5 days in jail sentence for reckless driving, but Lohan evaded jail for lockdown rehab.

Lohan teared up a little when Letterman praised her in the end.

"We never thought we'd see you again, honestly," Letterman said. "You have enough spin, enough sense of yourself, and enough poise to come out here and talk to me."