"There has been much speculation about Amanda's medical condition," her attorney Tamar Arminak tells PEOPLE exclusively. "She asked me to dispel certain rumors. For the record, Amanda does not have schizophrenia, nor has she ever been diagnosed with it."
Bynes's mother, Lynn, went a step further in a statement released Wednesday, saying, "Amanda has no mental illness whatsoever. She has never been diagnosed as schizophrenic or bipolar."
The actress, 28, who Tweeted pics of herself on April 5 looking happy and healthy while sunning in a bikini on vacation with her parents in Los Cabos, Mexico, was widely reported to be suffering from the disease and bipolar disorder.
A Bynes family source adds that the actress is making strides in treatment. "She continues to undergo outpatient therapy several times a week," the source says. "She's still working through the causes of her past bizarre behavior."
No Meds"Amanda currently is on zero medication," Arminak reveals. "She's devoted to living her life as healthy as possible. She's never had a history of abusing alcohol or hard drugs, and she's proud to say she's been marijuana-free for the past nine months."
Says Lynn: "Amanda is very sorry for all the hurtful tweets, statements and actions that occurred while she was under the influence of marijuana."
After enrolling as a student at the Fashion Institute of Design & Merchandising in Orange County, Calif., "Amanda is very happy studying fashion and she hopes to one day design her own line," Arminak says.
Bynes will remain under her mother's legal control until at least September and currently lives with her parents in L.A.
"Her family is closely involved with her day-to-day life but they try to give her as much autonomy as possible," explains Arminak. "She's doing extremely well. Her primary focus is bonding with her family and being a student."
Adds Lynn: "We're so proud of how far Amanda has come."