The Los Angeles County Fire Department confirmed that they responded to a call about a possible overdose at about 1:30 a.m. at Jackson's Calabasas home.
"Female 15 OD'd on 20 Motrin and cut her arm with a kitchen knife," the dispatcher says in audio released by authorities.
Officials would not release any further details, only saying a patient was transported to a local hospital.
The 15-year-old's mother, Debbie Rowe, told Entertainment Tonight that Paris attempted suicide. Rowe told ET she saw what appeared to be cuts on the teen's wrists. A source close to the family also told ET that Paris was upset over not being allowed to attend a Marilyn Manson concert slated for Thursday at Gibson Amphitheatre.
Rowe is Paris' biological mother, but Michael Jackson had full custody of Paris after he and Rowe divorced in the late 1990s.
Rowe's representative released the following statement to Eyewitness News:
"We appreciate everyone's thoughts for Paris at this time and their respect for the family's privacy."
Paris took to her Twitter account early Wednesday. She wrote, "i wonder why tears are salty?" and "yesterday, all my troubles seemed so far away now it looks as though they're here to stay."
Jackson family lawyer Perry Sanders released the following statement:
"Being a sensitive 15 year old is difficult no matter who you are. It is especially difficult when you lose the person closest to you. Paris is physically fine and is getting appropriate medical attention. Please respect her privacy and the family's privacy."
Paris' aunt, La Toya Jackson, also asked for privacy.
"We are grateful and appreciate the overwhelming concern for Paris from both the public and the media, but request privacy at this time while our family handles these issues together," she said.
The news about Paris comes as her family is involved in a major legal battle over her father's death. Paris is a plaintiff in this case, along with her brothers Prince and Blanket, and her grandmother Katherine Jackson.
The family matriarch usually sits in the front row to watch the testimony, but she was not in court on Wednesday.
The family is suing concert promoter AEG Live for the wrongful death of Michael Jackson, alleging that AEG hired Dr. Conrad Murray and failed to supervise him.
Wednesday, a central figure on the case was scheduled to take the stand - AEG Live President Randy Phillips.
News about Paris was not mentioned in the courtroom. The judge would not have wanted the jurors to hear any of that information. She has cautioned the jury repeatedly not to read or watch anything about the Jacksons, saying this case is to be tried only on the evidence presented in court.
A member of Katherine Jackson's team says there is no indication that Paris' role in the trial has anything to do with the suicide attempt.
"The Jackson attorneys are doing all we can to keep this trial as far away from the Jackson children and Paris as possible," said attorney Kevin Boyle.
Paris, however, is named as a witness by the defense. AEG subpoenaed her and Prince. Paris came to the court two months ago to give her deposition.
"A deposition, a grilling of a child regarding the loss of her father, is going to create a lot of pressure," said Boyle. "Paris Jackson was asked intimate details about her father and her father's death. It was a very intense situation. And yes, it created pressure on everybody involved."
Marvin Putnam, a defense attorney for AEG Live, released a statement expressing concern for Paris.
"We pray to God the reports are not true. God forbid that they are. We wish her a speedy recovery and her family all the best. I hope, I really hope she is okay," Putnam said.
The Jackson attorneys say if they call Paris Jackson to testify, it would be about her loss and her close relationship with her father. They said they have not decided yet whether they will be calling her.
Julia Thomas, one of many Jackson fans who always gather outside the court, called the news about Paris "saddening."
"She's a strong girl, she's very intelligent. It's a very trying time and I'm sure she's very overwhelmed," Thomas said. "It's just a lot. She lost her father, which was her main support system, like I said, she's going through school right now, she has finals. It's a lot. Bless her heart."