The postpartum period is a specific physiological and social risk window for mood disorders. Dramatic hormonal shifts (estrogen and progesterone plummet within 24 hours of delivery; prolactin rises with breastfeeding), sleep deprivation, immune-inflammatory changes, HPA axis recalibration, and the relational reorganization that accompanies a new baby produce conditions unlike any other in adult life.
Three distinct postpartum syndromes deserve recognition.
Postpartum depression affects roughly 10-15% of births in well-resourced settings; rates higher in disadvantaged populations. Symptoms typically begin within 6 weeks postpartum but can emerge up to 12 months later. Phenotype often includes anxiety alongside depression, intrusive thoughts about the baby (often violent or harm-related but ego-dystonic — the parent fears their own thoughts), feelings of inadequacy about parenting, sleep disturbance beyond newborn care. Treatment: sertraline preferred for breastfeeding given safety data, brief perinatal-focused psychotherapy, brexanolone or zuranolone for moderate-severe cases (allopregnanolone-derived agents specifically FDA-approved with rapid onset).
Postpartum psychosis is a psychiatric emergency. Rare (1-2 per 1,000 births) but life-threatening. Typically presents in the first 2 weeks with rapid-onset confusion, mood lability, paranoid delusions (often baby-related — fears the baby has been switched, harmed, possessed), auditory hallucinations, sleep disturbance disproportionate to newborn care needs. Risk of infanticide and suicide is substantial — both real and concrete in many cases. Hospitalization required. Antipsychotic medication, mood stabilizer (lithium often used despite breastfeeding considerations), supportive care. Postpartum psychosis is often a first presentation of bipolar disorder. Recurrence in subsequent pregnancies is high (40-50%) — pre-pregnancy mood stabilizer planning appropriate.
Postpartum OCD is the most often-missed of the three. Pattern: intrusive harm-related thoughts about the baby (the parent has thoughts of harming the baby that they find deeply disturbing and unwanted), compulsive checking behaviors (checking the baby is breathing, checking locks, checking themselves), avoidance of being alone with the baby. These intrusive thoughts are ego-dystonic — the parent does not want to act on them and fears their own mind. This is distinct from postpartum psychosis, where harmful thoughts are often ego-syntonic and acted upon. Treatment: high-dose SSRI plus CBT with ERP, family support, explicit reassurance that intrusive thoughts of this type in postpartum OCD do not predict action.
A clinical principle: every postpartum patient deserves screening for mood symptoms at the postpartum visit (Edinburgh Postnatal Depression Scale widely used). Family members should be specifically asked about behavior changes. Bipolar history requires perinatal psychiatric planning before delivery. The postpartum period is too physiologically specific to leave to general primary care follow-up without proactive mental health attention.