By Breaking Celebrity News Staff

Amanda Bynes isn't letting her recent DUI arrest slow her down. The former Nickelodeon star hit both the Chateau Marmont and the hip nightclub Greystone Manor Thursday night, despite pleadings from some around her to go into rehab.

"Amanda has been in a downward spiral for the last six months. Even though her dad publicly said she doesn't drink, he knows she has a problem. It's truly sad to witness. Amanda has been told she must go to rehab, but she is refusing," a source close to Bynes tells Breaking Celebrity News exclusively.

As  a source told The New York Post, "She is not the same girl as she was a year ago. She is just doing whatever she wants to. do. Friends are concerned because she is not the Amanda they know.”

As Breaking Celebrity News previously reported, Bynes was arrested in the early morning hours of April 6 after she hit a police car.  She was arrested and charged with DUI. She's now out on $5,000 bail pending her first court hearing.