Lindsay Clancy’s defense in her murder trial rested on Friday after calling witnesses to testify about the ailing mother’s mental state and attempts to seek help before she killed her young children.

The defense wrapped more quickly than some expected given that the prosecution rested their case on Monday.

Prior to resting, the defense called forensic psychiatrist Dr Phillip Resnick to the stand; Resnick was an integral witness in the murder trial of Andrea Yates. In 2001, Yates drowned her five children in Texas and, in 2006 after a retrial, was found not guilty by reason of insanity. Medical professionals, including Resnick, testified that Yates suffered from severe postpartum psychosis.

While Clancy’s defense lawyers have not disputed that she fatally strangled her children, they argue she should not be held criminally responsible because she had postpartum psychosis. Massachusetts prosecutors contend that Clancy, 36, intentionally killed her children Callan, Dawson, and Cora, who were eight months, three years and five years old respectively. Prosecutors said Clancy then faked a suicide attempt.

After the defense rested, the prosecution went on to present their rebuttal case, offering three witnesses before moving to closing arguments. A rebuttal from the prosecution is standard in insanity defense cases.

The first rebuttal witness called was forensic psychiatrist Dr Avram Mack, who contended that when he spoke to Clancy in April, “she described feeling miserable, not wanting to be alive”.

Assistant district attorney Shanan Buckingham asked if, in Mack’s opinion, Clancy retained the ability to conform her behavior with the law and be aware of the wrongfulness of her acts.

“[Clancy] had retained that capacity,” Mack said, later saying that while Clancy likely suffered from a major depressive episode and anxiety, he did not see evidence that she was ever bipolar in a manic state.

“I can appreciate that she felt side effects and a degree of change from the medications that she took. I don’t know that that feeling or belief is necessary psychotic,” Mack said on the stand.

During cross-examination, the line of questioning to Mack from Kevin Reddington, Clancy’s defense lawyer, became contentious. Reddington criticized Mack for educating himself about Clancy’s background only through Clancy herself, while she was medicated in a psychiatric hospital, and without interviewing other people from her life.

Asked about Clancy’s condition in the aftermath of the birth of Callan, Mack testified that Clancy had been anxious about returning to work and having a nanny.

“There was some degree of wanting to be able to handle the children on her own,” Mack said. “She felt very positively about her ability to take care the children, but also some ambivalence about other people being able to take care of the children.”

Judge William F Sullivan said if all testimony concludes by end of day on Friday, closing arguments will likely be held on Monday. If testimony continues until Monday, closings would likely be held Tuesday.

Clancy faces a sentence of life in prison without parole if convicted of first-degree murder. Should jurors decide that she was not criminally responsible, Clancy would be held in a state psychiatric facility.

The trial has become a flashpoint in the US’s approach to maternal health care – especially after birth. The case has rekindled discourse about the under-diagnosis of postpartum depression and the much rarer condition of postpartum psychosis.

Researchers have estimated that postpartum psychosis affects roughly one to two women per 1,000 after giving birth, per the Cleveland Clinic. The condition “affects a person’s sense of reality, causing hallucinations, delusions, paranoia or other behavior changes”. In severe cases, “people with PPP may attempt to harm themselves or their newborn”, the clinic notes.

Hundreds of women gathered outside the courthouse on Thursday in support of Clancy, with many donning pink clothing with statements such as “She Needed Help”.

“Women are being dismissed, neglected and ignored when we speak up,” April Vincent, who was in attendance, said. “We’re scared because nobody takes us seriously.”