No clear cause has been identified for the postpartum blues, postpartum depression (PPD) or postpartum psychosis (PPP). There is evidence, however, that physical changes may play a role in the development of these conditions.

Immediately after childbirth, the hormone levels in the body fluctuate. Estrogen and progesterone levels, which increase during pregnancy, decrease dramatically. This can trigger depression, although the reason for this is not completely understood. Hormones produced in the thyroid (a gland located at the base of the neck that regulates metabolism) drop sharply, which may result in feelings of fatigue, sluggishness and depression. Other changes in the amount of blood in the body, blood pressure, immune system and metabolism can cause fatigue or mood swings.

Risk factors for PPD include a personal or family history of depression and/or conditions such as bipolar disorder, severe premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). About half of women diagnosed with PPD have a history of depression. Women who have had PPD with prior children are also at greater risk for developing the condition again. Other risk factors include:

• Emotional changes. The demands of caring for a baby coupled with sleep deprivation can lead to frustration and depression. Other emotional influences that may contribute to depression include:
  
  
• • Identity crisis. Some women have difficulty reconciling their new role as mother with their identity prior to giving birth.
  • Childbirth difficulties. Medical complications and other factors can make it difficult to care for a baby.
  • Unrealistic expectations. Some women worry about being perfect mothers.
    
  • Feelings of being unattractive, overwhelmed or out of control.
    
• Lifestyle changes. Some circumstances following birth can lead to anxiety and depression, such as:
  
  
• • Baby with greater than average needs
  • Medical problems following childbirth
  • Fatigue from caring for a baby or multiple children
  • Poor education about childrearing techniques
  • Financial problems
  • Childcare concerns
  • Lack of support from family and friends
  • Difficulty with breastfeeding
  • Relationship problems
  • Major life changes (e.g., changes in career, moving)

Other factors that may increase the risk of PPD include:

• History of pregnancy or delivery complications
• Marital conflict
• Lack of perceived support from family, friends and others
• Living without a partner
• Stress related to childcare issues
• Unplanned pregnancy
• Previous miscarriage
• Lack of emotional or financial support from a spouse or partner