She's not just another "celeb" going to rehab, this ho might actually have a problem. Better yet, she may actually want to fix her addiction. No damage control here, say it ain't so!

Mischa Barton's little sister Hania is the latest beeyotch to get addicted to sumthin sumthin.

The 19-year-old "actress" (yes, I'm using the term loosely) was apparently getting "out of control," and has checked into rehab to treat an addiction to pain killers.

"Everyone is hoping that this will be the first and last time Hania has to be in rehab," says a source close to the Barton family. "She's young, but she's a smart girl, she will be fine."

Mischa is apparently pissed off and concerned, but happy her sister is getting help. The name and location of what rehab facility Barton is attending has not been released.

But everyone knew where Lindsay was staying. This Hania ho is getting special treatment already! I'm only kidding, I don't even know who the eff she is.

Get better soon mystery-person-sibling-what's-her-face, who?

source