Lindsay Clancy case: Can postpartum psychosis drive a mother to kill her children?

Lindsay Clancy says postpartum psychosis drove her to kill her children. Can it actually happen?

In Short

• Doctors say the condition is rare and most mothers never harm children
• Defence claims Clancy heard a male voice ordering her to kill
• Prosecution accepts mental illness but disputes psychosis during the children's killings

The Lindsay Clancy murder trial has put a disturbing question at the centre of the courtroom: can postpartum psychosis drive a mother to kill her own children?

The medical answer is yes, but with an important caveat. It is an exceptionally rare outcome, and the overwhelming majority of women experiencing postpartum psychosis do not harm their children.

“Postpartum psychosis is not simply extreme sadness or an intensified form of postpartum depression,” clinical and forensic psychologist Kanishka explains. “It is an acute psychiatric emergency in which a person may lose contact with reality through delusions, hallucinations, severe confusion, or even something related to mania as well.”

Postpartum psychosis affects around one to two women in every 1,000 births. In the most severe cases, a mother may develop a delusional belief that her child is possessed, condemned or facing an unbearable catastrophe, and that death is the only way to protect the child.

“This is sometimes called altruistic filicide,” Kanishka says. “The term is descriptive. It does not suggest that the act is actually compassionate.”

Research has found an association between psychotic symptoms and maternal filicide. A 2025 case-control study of 30 women who had committed filicide found that psychotic symptoms, severe insomnia and a vulnerability to bipolar or schizophrenia-spectrum disorders were associated with filicide. But the researchers cautioned that the findings cannot be used to predict what an individual woman with postpartum mental illness will do.

The distinction is crucial in the Clancy case.

The defence has argued that Clancy had bipolar disorder and postpartum psychosis, and that she experienced a command hallucination — a male voice ordering her to kill her three children. Defence experts Phillip Resnick and Paul Zeizel testified that she was psychotic and unable to appreciate the wrongfulness of her actions.

Prosecution experts have offered a different interpretation. Psychiatrist Avram Mack and forensic psychologist Kirk Heilbrun accepted that Clancy was seriously mentally ill but disputed that she was psychotic when the killings occurred. Heilbrun described the killings as “altruistic filicide” arising from Clancy's desire to die and her belief that her children would suffer without her. FBI-affiliated forensic psychiatrist Gregory Saathoff also questioned her account of hearing a commanding voice.

There is another complication: timing.

Clancy killed her children about eight months after the birth of her youngest child. The DSM-5-TR's “with peripartum onset” specifier is limited to symptoms occurring during pregnancy or within four weeks after delivery. That does not by itself rule out a postpartum-related illness, but, as Kanishka explains, the unusually late timing means there needs to be stronger evidence connecting childbirth, the developing illness and the psychotic symptoms.

And this is where postpartum psychosis must be separated from postpartum depression.

Depression primarily affects mood: persistent sadness, hopelessness, guilt, loss of pleasure, exhaustion and, in severe cases, suicidal thoughts. Reality testing is generally preserved.

Postpartum psychosis, by contrast, can involve hallucinations, delusions, paranoia, severe confusion, mania and profoundly reduced insight. It is a psychiatric emergency requiring immediate assessment and often hospitalisation.

As Kanishka puts it: “Postpartum psychosis is severe but treatable.” The rare cases in which psychosis is associated with violence should not obscure the much bigger message — recognising hallucinations, delusions, severe confusion or rapidly changing behaviour early can save lives.

Meanwhile, after weeks of testimony from competing medical experts, closing arguments are scheduled for August 27. The jury is expected to begin deliberations after the arguments, but there is no fixed timeline for a verdict.

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