Mueller, who is the mother of Sheen's twin sons, Max and Bob, checked herself into a treatment facility on Monday night (10Dec12) due to issues with Adderall, a drug used to help control conditions such as attention deficit disorder.
Her lawyer, Yale Galanter, tells TMZ.com, ""Brooke was uncomfortable with the way Adderall was making her behave. Brooke continues her lifelong battle with drug addiction by taking these steps herself to prevent a further drug relapse.""
Mueller's latest stint in rehab comes after she was taken to hospital on Friday (07Dec12) when she was found unresponsive by an assistant at her home in Tarzana, California.
She was discharged and diagnosed with ""exhaustion and dehydration"", according to her publicist.