What is the recommended screening and first‑line treatment for late‑onset postpartum depression in breastfeeding and non‑breastfeeding women, including medication choices, treatment duration, follow‑up schedule, and criteria for specialist referral?

Late-Onset Postpartum Depression: Screening and Treatment

Screen all postpartum women using the Edinburgh Postnatal Depression Scale (EPDS) with a cutoff score ≥10, and initiate sertraline 25-50 mg daily as first-line treatment for both breastfeeding and non-breastfeeding women with moderate depression, advancing to 50 mg daily for severe depression. 1, 2

Screening Protocol

Use the EPDS as the primary screening tool for postpartum depression, as it demonstrates 95% sensitivity and 93% specificity and is validated across over 60 languages. 3, 1, 2 The EPDS is a 10-question instrument evaluating symptoms over the past 7 days, with scores ranging 0-30. 3, 2

• Score ≥10 indicates possible depression requiring further clinical evaluation 3, 1, 2
• Score 10-14 suggests moderate depression 1
• Score ≥15 indicates severe depression requiring immediate treatment 1

The Patient Health Questionnaire-9 (PHQ-9) serves as an acceptable alternative, though the EPDS remains the gold standard with the strongest evidence base. 3, 2

Timing of Screening

Depression prevalence peaks at 12 weeks postpartum (17.4%) and continues rising through the first year, necessitating ongoing surveillance beyond the immediate postpartum period. 1 Screen at the initial postpartum encounter and continue periodic screening throughout the first year. 3, 1

Critical Assessment Components

Immediately screen for suicidal ideation using EPDS question 10 or direct questioning, as suicide represents the second most common cause of maternal mortality. 3, 1, 2

Assess for psychotic symptoms, as postpartum psychosis affects 1-2 per 1000 births and represents a psychiatric emergency requiring immediate specialist referral. 1

Screen for comorbid anxiety disorders, which occur in approximately 16% of postpartum women and commonly co-occur with depression. 3, 1, 2

Evaluate for hypothyroidism in women presenting with depression, particularly if a gravelly voice is present (suggesting laryngeal myxedema), as postpartum thyroiditis occurs in 5-10% of women and can manifest up to 12 months after delivery. 1

First-Line Treatment

For Breastfeeding Women

Sertraline is the preferred SSRI for postpartum women due to minimal passage into breast milk and decades of safety data, as recommended by the American Academy of Pediatrics. 1, 4

Dosing algorithm:

• Moderate depression (EPDS 10-14): Initiate sertraline 25-50 mg daily 1
• Severe depression (EPDS ≥15): Start sertraline 50 mg daily immediately 1

Most antidepressant medications are considered compatible with breastfeeding, though sertraline has the most robust safety profile. 4, 5

For Non-Breastfeeding Women

Use the same sertraline dosing protocol as for breastfeeding women, as it represents the first-line pharmacologic treatment regardless of breastfeeding status. 1, 4

Psychotherapy

Evidence-based psychotherapy (cognitive behavioral therapy or interpersonal therapy) should be offered concomitantly with medication or as monotherapy for mild-to-moderate cases. 6, 7, 5 Many patients benefit from combined treatment with both psychotherapy and medication. 6

Treatment Duration

Continue antidepressant medication for 6-12 months postpartum to ensure complete recovery and prevent relapse. 6, 5 Inadequate treatment duration puts women at risk for chronic, recurrent, or refractory depression. 6

Follow-Up Schedule

Schedule monthly follow-ups during the first 3 months of treatment, then every 2-3 months if stable. 1

At each visit:

• Readminister the EPDS to track symptom severity and treatment response 2
• Document therapy engagement, frequency, and perceived effectiveness 2
• Reassess for suicidal ideation and safety concerns 2
• Screen for emerging anxiety symptoms 1, 2

Criteria for Specialist Referral

Immediate psychiatric referral is required for:

• Psychotic symptoms (hallucinations, delusions, disorganized thinking) 1
• Active suicidal ideation with plan or intent 1, 2
• Severe depression (EPDS ≥15) not responding to initial treatment within 4-6 weeks 1
• History of bipolar disorder or other severe mental illness 5

Consider referral for:

• Moderate depression not improving after 8-12 weeks of adequate treatment 7
• Significant comorbid anxiety requiring specialized management 1
• Patient preference for specialized psychiatric care 7

Critical Warnings

The risk of untreated maternal depression (impaired maternal-infant bonding, adverse effects on infant cognitive and emotional development) generally outweighs minimal medication risks. 3, 1 Untreated postpartum depression affects the newborn's cognitive, behavioral, and emotional development, with effects potentially lasting into adolescence. 3

Common pitfall: Underdiagnosing postpartum depression because symptoms are dismissed as normal postpartum adjustment. The prevalence is 13-19% within the first year, making it one of the most common complications of childbirth. 3, 7, 5