Lindsay Clancy, a labor and delivery nurse at the prestigious Massachusetts General Hospital in Boston, is the latest tragic and high-profile example of a mother allegedly taking the lives of her own three children.

On Jan. 24, 2023, Clancy allegedly strangled the children with an exercise band while her husband ran an errand. Clancy then slit her wrists, cut her neck and jumped from the second floor of their home. She has been hospitalized since, apparently paralyzed from the waist down following her suicide attempt.

At her arraignment, Clancy’s defense lawyer stated that she may have been suffering from an extreme form of postpartum depression called postpartum psychosis. Other women have made this claim, including Andrea Yates, a Texas woman who in 2001 drowned her five children in a bathtub. She was convicted of capital murder at her first trial, but after a successful appeal, she was found not guilty by reason of insanity in her second trial.

The Centers for Disease Control and Prevention estimate that 1 in 8 mothers, or approximately 12%, experience postpartum depression. Cases of parents killing children, in contrast, are exceedingly rare, with estimates of about 500 of these tragic events per year in the U.S.

Many people wonder whether a psychiatric condition, no matter how severe, could justify or explain the killing of innocent children, especially by their own mother.

As a clinical and forensic psychiatrist, I routinely treat patients after delivery for depression, and I have evaluated women accused of killing their children. The potentially fatal outcomes make it imperative to increase awareness and understanding of postpartum depression and psychosis.

Postpartum depression explained

It is important to make a distinction between “postpartum blues” and postpartum depression. Research shows that between 15% to 85% of women have “postpartum blues,” and the incidence peaks around the fifth day following delivery. Postpartum blues can include low mood, tearfulness, irritability and feeling overwhelmed. It is a totally normal, transient condition thought to be a result of the rapid drop in hormone levels following delivery.

True postpartum depression is more severe than postpartum blues. This term refers to when the patient is experiencing symptoms of a clinical depressive episode, also called “major depressive episode,” usually within the first month after delivery.

Postpartum depression is defined as experiencing two weeks or more of some or all of the following symptoms: depressed mood for most of the day, diminished interest or pleasure in most activities, weight loss, inability to sleep or excessive sleep, physical slowing or agitation, fatigue, poor concentration and, in severe cases, suicidal thoughts. The medical community estimates that postpartum depression is very common, with rates of 10% to 20% in the U.S., and the true numbers may be higher.

The onset and duration of postpartum depression can vary greatly. For some patients, the first weeks and months after delivery may go well or mood symptoms may be manageable, followed months later by a “crash.” For others, mood symptoms may begin during pregnancy and worsen after delivery.

Diagnosis can be difficult since the time of onset is variable and because some of the symptoms of depression are normal, temporary changes that occur after delivery. In addition, research shows that cultural factors can influence the reporting and development of postpartum depression, and some patients may not disclose symptoms due to guilt or shame.

Risk factors for postpartum depression

Some key risk factors for postpartum depression include a history of depression or mental illness prior to pregnancy, stressful life events during and after pregnancy, marital conflict and young maternal age.

New mothers are under a great deal of pressure – personal, familial and societal – to immediately bond with and love their children. The stress and burden of being a new parent, and the tasks that go along with this role, such as breastfeeding, often make bonding with the child a challenge. The patient may struggle with feelings of guilt and shame, which can delay or prevent seeking help.

While the physical causes of postpartum depression remain mysterious, researchers believe the condition is caused by hormone fluctuations during and especially after pregnancy. For example, research suggests that sex hormones like estrogen, which reach high levels during pregnancy and then fall precipitously after delivery, as well as hormones like oxytocin that are involved in lactation and maternal-baby bonding, likely play an important role. During and after pregnancy, the brain is on a hormonal roller coaster, and this can wreak havoc on mental health.

Postpartum depression treatments

For mild cases, psychotherapy alone may be sufficient to reduce the symptoms and gradually restore a sense of well-being. Approaches such as interpersonal psychotherapy and cognitive behavioral therapy have been shown to be helpful for those suffering with postpartum depression. Interpersonal psychotherapy, for example, focuses on improving interpersonal connections, while cognitive behavioral therapy focuses on correcting distorted thinking, such as believing that one is a “bad” parent.

The mainstay of treatment for postpartum depression is medication. Given the probably strong biological underpinnings of this condition, medication is thought to be helpful in restoring neurochemistry to alleviate symptoms, such as by raising brain levels of the neurotransmitter serotonin.

Breastfeeding patients may prefer psychological treatment to medication therapy since antidepressants can enter breast milk. To date, however, antidepressants do not appear to have an affect on the infant’s health or development.

How postpartum psychosis differs

Postpartum psychosis is a condition where maternal mental health is affected not just by depression, but by a break with reality.

The break with reality, called “psychosis,” generally includes seeing or hearing things that don’t exist – called hallucinations – having jumbled or disconnected thoughts or having fixed false beliefs, often of a bizarre or extremely implausible nature, such as the devil having entered into one’s child. For example, in the Andrea Yates case, she professed to believing that she was marked by Satan and that the only way to save her children from hell was by killing them. Some patients may hear an auditory hallucination - meaning a powerful voice - commanding suicide or an attack on the infant.

This condition is much less common than postpartum depression and is thought to occur in 1 in 500, or 0.2%, of deliveries in the U.S. Also, unlike postpartum depression, which can begin months after delivery, postpartum psychosis usually begins within the first three days following childbirth.

Due to the severe nature of these symptoms, their rapid onset and the frequent presence of thoughts of harming oneself or the baby, postpartum psychosis is considered a psychiatric emergency. It usually results in psychiatric hospitalization for the patient’s and the baby’s safety. In many cases, postpartum depression and its extreme form, postpartum psychosis, go undetected by loved ones and health care providers because of a reluctance to acknowledge that the patient may be a danger to oneself or the child.

What experts know about Clancy’s Case

Lindsay Clancy reportedly suffered from anxiety about going back to work in September 2022, four to five months after giving birth to her third child. She was diagnosed with anxiety and prescribed anti-anxiety medications and antidepressants.

In December 2022, Clancy was evaluated at a women’s psychiatric clinic, where she was told she did not have postpartum depression. However, a short time later she told her husband she was having thoughts of harming herself and the children, and was admitted to a psychiatric hospital. She was discharged after a few days and reported that her suicidal thoughts had resolved. However, just a few days later, she allegedly strangled her three children.

If accurate, this timeline indicates how difficult it can be to diagnose possible postpartum depression and psychosis, and that symptoms may fluctuate on a daily or even hourly basis. Mothers may not always disclose symptoms due to guilt, shame or fear about how it could impact their family.

Clancy’s tragic story illustrates how important close mental health follow-up and treatment is for women suspected of having postpartum depression. And when suicidal thoughts or thoughts of harming the children are present, they must be treated as a potential psychiatric emergency.

Ziv E. Cohen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.