A Massachusetts jury is hearing arguments in the trial of former nurse Lindsay Clancy, who killed her three children in 2023. Her defense claims she was experiencing untreated postpartum psychosis exacerbated by inadequate medical care.

The defense called 10 witnesses to testify about Clancy’s mental state prior to the killings, focusing on her struggles to receive proper diagnosis and treatment. Court documents and clinicians’ testimony confirm that Clancy was not formally diagnosed with postpartum psychosis. Dr. Alia Goodheart, the psychiatrist treating Clancy during an inpatient stay at McLean Hospital, stated she 'probably' has not treated anyone with postpartum psychosis and did not order lab work, such as thyroid levels, or use standardized scales to determine the severity of Clancy's condition.

From September 2022 until January 2023, Clancy repeatedly sought help for severe postpartum depression, insomnia, and anxiety through outpatient providers, emergency room visits, suicide hotlines, and voluntary inpatient treatment. Clancy wrote a detailed note in October 2022 expressing doubts about her parenting choices. Her phone contained search history related to hallucinations, psychosis, and drug side effects in the weeks before the killings.

Postpartum psychosis occurs in 1 to 2 per 1,000 births. In 2025, an estimated 3.6 million people gave birth. Based on 2025 birth rates, at least 3,600 people experienced postpartum psychosis.

Postpartum psychosis is not currently included as a separate diagnosis in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). There is momentum to add postpartum psychosis to the DSM-5. Dr. Veerle Bergink is leading an initiative to get postpartum psychosis uniquely classified in the DSM.

Having bipolar disorder increases a person's risk of postpartum psychosis from approximately 0.1% to about 20%. People with a prior case of postpartum psychosis have a risk of developing it again of just over 30%. Untreated postpartum psychosis carries a 4% risk of a mother wanting to harm herself or her baby.

Most people develop postpartum psychosis symptoms within the first two weeks after giving birth, often around days eight to ten. Postpartum psychosis episodes usually begin sometime within the first three months postpartum.

"Typically, the first symptoms are clear within one or two weeks of delivery: irritability, sleep loss, ideas getting more and more weird, mood swings going one way or the other," psychiatry and OBGYN professor at the Icahn School of Medicine at Mount Sinai Bergink said. "If left untreated, there’s a high risk of both suicide and infanticide — especially suicide."

"A lot of times when we see postpartum psychosis, we see it in the context of bipolar disorder," perinatal psychiatrist and professor at the UMass Chan Medical School Nancy Byatt said. "There's a particular risk with bipolar disorder." Byatt added that this is very different than what could be seen in severe postpartum psychosis, which constitutes a psychiatric emergency.

"Women may appear ‘off’ or unwell at one part of the day and then ‘better’ or like their usual self later on. This waxing and waning mental status is often misunderstood as a sign of improvement, when it’s actually a very concerning and hallmark red flag for postpartum psychosis," reproductive psychiatrist Katrina Furey said. Psychiatrist at Radial Greg Malzberg noted that postpartum psychosis often looks less like a ‘primary psychotic disorder’ and more like a severe bipolar-spectrum episode triggered by childbirth, with mania, mixed states, or depression plus psychotic symptoms.

"I think one of the things that’s hard is that when someone’s experiencing this, to them, everything is very real," mental health counselor at Certain Counseling Christine Certain said. Certain explained that a person might believe they gave birth to a lion rather than a person. "We don’t wanna stigmatize. We don’t wanna tell anyone that, you know, that they’re flawed or that they have done something wrong because it’s not something that they had control over," Certain said.

A 2015 study led by Bergink found that 98% of patients who take prescribed treatments can fully recover from postpartum psychosis. The median time period for recovery from postpartum psychosis with treatment is about one month. "It typically takes a few weeks (for symptoms to resolve). The psychotic and manic symptoms resolve first, and then the depressive symptoms usually linger a bit longer," he said.

"It's like an altruistic delusion," Bergink said, describing a belief some mothers may have that killing their child is an act of protection.

Postpartum depression affects one in eight new mothers, according to the Centers for Disease Control. Perinatal mood and anxiety disorders can begin at conception and last until a year after birth. Postpartum psychosis has been documented as far back as the fifth century B.C.

Timeline

Lindsay Clancy killed her three children at their Massachusetts home in 2023. On January 24, 2023, Lindsay Clancy fatally strangled her three children, Cora, Dawson, and Callan, and was found unconscious outside the family's home in Duxbury, Massachusetts, after attempting suicide.

What's New

Clancy's defense argues she was experiencing postpartum psychosis when she killed her children. Lindsay Clancy's defense attorney, Kevin Reddington, argued that she suffered from postpartum psychosis, with Reddington stating that 'lousy medical care' exacerbated her condition. "There have been case reports (on postpartum psychosis) for hundreds of years, and we know how high the risk is and how specific this disease is and it’s not included in our classification system," he said.

How Sources Differ

Risk factors also vary in description across sources.

Characterizations of the condition differ among experts.

Why It Matters

The trial shows the legal and medical complexities surrounding postpartum psychosis, a condition not currently included as a separate diagnosis in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). With momentum building to add the condition to the DSM-5, advocates argue that unique classification would improve recognition and reduce stigma. The case reflects the stakes for families and medical providers, as untreated postpartum psychosis carries risks, including a 4% risk of a mother wanting to harm herself or her baby.

The proceedings examine whether inadequate medical care contributed to the tragedy, with the defense calling attention to missed diagnostic opportunities. As the jury deliberates criminal responsibility, the outcome may influence how similar cases are viewed in the context of mental health crises following childbirth. Experts emphasize that early recognition and treatment are critical to preventing severe outcomes, noting that 98% of patients who take prescribed treatments can fully recover.