What Is Postpartum Depression?

Postpartum depression (PPD), also known as perinatal depression, is a serious form of depression that affects some people after giving birth. Although it typically begins within the first three months after delivery, it can occur any time within the first year.

Unlike “baby blues,” which usually go away within two weeks, PPD lasts longer, is more severe, and significantly affects a person's ability to care for themselves or their baby.

Researchers haven’t pinpointed a single cause of PPD, but they believe it's likely due to a combination of factors including hormonal changes, genetics, lack of social support, and environmental stressors. While certain risk factors may increase the likelihood of developing PPD, it can happen to anyone after childbirth.

Theories Behind Postpartum Depression

The exact cause of postpartum depression remains unclear, but several theories offer possible explanations.

Hormonal Changes

During pregnancy, estrogen and progesterone levels rise significantly. After birth, these hormone levels drop rapidly, and some experts believe this sudden hormonal shift may contribute to depression in certain individuals.

Stress

The transition to parenthood can be extremely stressful. Factors such as sleep deprivation, changes in personal identity, lack of support, and the overwhelming responsibility of caring for a newborn can all contribute to the onset of PPD—especially when combined with hormonal changes. People who are more genetically vulnerable to stress may be more affected.

Thyroid Imbalances

Thyroid hormone levels can also fluctuate after childbirth. If the thyroid produces too little hormone, symptoms of depression may occur. Since many thyroid-related symptoms go undiagnosed, it’s important to check thyroid function if depression appears postpartum. Fortunately, thyroid issues can often be managed with medication.

Is Postpartum Depression Hereditary?

There is no single gene that causes PPD, but genetics may still play a role. People with a family history of mental health conditions are more likely to develop postpartum depression. In addition to genetics, childhood environment and a lack of support from family members may also increase the risk.

Who Gets Postpartum Depression?

While anyone can develop postpartum depression, some individuals are more vulnerable than others.

Those with a personal or family history of psychiatric conditions such as depression or anxiety are at higher risk. Past experiences of sexual abuse or having premenstrual syndrome (PMS) may also elevate risk. Additionally, feelings of disappointment or discomfort related to the baby’s sex may contribute.

Other risk factors include:

  • A difficult or traumatic pregnancy or delivery

  • Lack of support from a partner, family, or friends

  • Living in an environment with domestic violence

  • Being single or in a strained relationship

  • Being under the age of 25

  • Experiencing breastfeeding difficulties

  • Having a premature baby or one with complex medical needs

  • An unplanned pregnancy

  • Struggles with alcohol or drug use

  • Going through major life stressors during pregnancy, like a serious illness or the loss of a loved one

  • Financial stress or unstable access to food and housing

Risk Factors for Postpartum Depression

Medical Risk Factors

Individuals who experienced medical complications during pregnancy or childbirth are more likely to experience PPD. This includes high-risk pregnancies, extended hospital stays, or traumatic births—such as emergency C-sections, complications during labor, or cord issues. Medical complications following birth, like a premature baby or one with low birth weight, can also contribute to increased risk.

Social Risk Factors

Lack of social support is one of the strongest contributors to postpartum depression. New parents who feel isolated or unsupported by partners, family, or community are much more likely to experience depression than those who have emotional or practical support.

Lifestyle Risk Factors

While diet and exercise alone don’t directly cause postpartum depression, poor lifestyle habits can increase the likelihood. Unhealthy eating, inactivity, and extreme sleep deprivation can contribute. Some studies also suggest that a deficiency in vitamin B6 may be linked to increased risk.

Parenting and Infant Risk Factors

Caring for a baby with special needs, a colicky infant, or a child born prematurely can increase emotional stress and the likelihood of PPD. First-time parents and those who become parents at a very young or older age may also face a higher risk.

A Quick Review

Although the exact cause of postpartum depression is unknown, it's believed to result from a mix of hormonal, genetic, social, and environmental factors. Understanding the possible causes and risk factors can help individuals and their loved ones recognize and seek support for PPD early.