Amanda Bynes takes illegal drugs "all day, every day," according to her publicist Jonathan Jaxson.
"I fear she is going to end up like Amy Winehouse if she doesn't get the help she so desperately needs. She is smoking 30-plus joints a day and doing cocaine," reports Yahoo!.
"Then there's the plastic surgery. In the six months I was trying to do damage control she had several surgeries, they weren't massive operations, usually day-long procedures, but she didn't need them."
According to Jaxson, who started working with the 27-year-old actress after her second hit-and-run accident, substance abuse drastically affected her personality. She's "the sweetest girl in the world" when she's sober, he said.
"Sadly she is strung out on drugs and paranoid most of the time. People say she has mental health problems but I think it's just the drugs," he said.
"She doesn't really drink, she just does drugs all day, every day," he added.
Bynes, who is currently being held in a psychiatric unit following a bizarre incident last week in which she set a driveway on fire by her parent's home in Southern California, has been diagnosed with schizophrenia.
During a hearing at the Ventura County, Calif., mental facility where the former child star is being held on an extended involuntary psychiatric hold, Bynes' doctors told a judge Thursday that she is being treated for schizophrenia.
"Amanda's doctors and a social worker told the judge that Amanda is being treated for schizophrenia," a source told RadarOnline.com.
"Although a formal diagnosis will be finalized in the next several days, it's almost certainly schizophrenia. Reports that said she was responding well to the psychiatric drugs that were being given to her are wrong. It can take months, or even years to get someone like Amanda to find the right drug combination and then get her therapeutic."
The insider added that, "The good news is that schizophrenia is treatable. It's a very serious diagnosis, but Amanda can live a long and healthy life, as long as she takes her prescribed medications. She can function in society and still work."
The ex-Nickelodeon star will remain at the hospital until at least Aug. 9, when a judge in probate court will rule on her parents' request for conservatorship.