TMZ is reporting that Mueller, 34, signed into an in-patient center a few weeks ago. The publication says, according to a source close to Sheen, Mueller seemed out of sorts during a recent visit to his home. It was not long after that the actress/reality star decided to pursue treatment.
This marks the second time this year that Mueller has spent time in rehab. She did so after the December 2011 cocaine arrest.
As part of her plea deal, Mueller reportedly must offer periodic urine samples. Should one of those indicate drugs in her system, she could face jail time.