A mother accused of repeatedly injecting her 4-month-old son with salt water will be sent to a state mental hospital after a psychiatrist testified Thursday that she is severely depressed.

Judge Jeffrey Manning ordered Amber Brewington, 21, of Duck River, Tenn., to spend no more than 90 days at Mayview State Hospital.

Psychiatrist Christine Martone, who evaluated Brewington on two occasions, testified at the competency hearing that Brewington should be tested for Munchausen by proxy, a syndrome in which a caregiver fakes or induces illness in others to generate sympathy.

Brewington also has a borderline personality disorder, is severely depressed and admits having suicidal thoughts, Martone said.

“Right now, here, today, she would not be able to cooperate with an attorney,” Martone said.

Brewington has been accused of poisoning her son, Noah King, with salt water. She was arrested after a nurse at Children’s Hospital of Pittsburgh told police she saw Brewington disconnecting the baby’s feeding tube. She is charged with attempted homicide and other crimes.

Brewington told police she injected Noah with salt water at least five times, including while he was being treated at Vanderbilt University Medical Center in Nashville, Tenn. King was transferred July 9 to the Pittsburgh facility, where he remains hospitalized in critical but stable condition.

Brewington appeared at her behavioral evaluations with self-inflicted symmetrical cigarette burns on her forearm and hand, Martone said. She has been under a suicide watch at the Allegheny County Jail.

Brewington was able to answer questions and provide details about the chain of events that led to her arrest. But Martone said she is so depressed she would be unable to cooperate with her court-appointed attorney, Duke Morris, to prepare her defense.

“She doesn’t want to live, so she doesn’t help in her defense,” Martone said.

Morris said he spent about 45 minutes with Brewington early Thursday and felt she needed to receive psychiatric treatment before she could be tried. He said Brewington’s responses were “extremely labored, deliberate” and not completely lucid.