Table 1.

Overview of included studies

Study	Population	Country	Intervention (all studies reported usual or routine care as the comparator)
Boath et al 28	Women being treated for postnatal depression n=60.	UK	Treatment Access to psychiatric day hospital, Monday–Friday 08:30–16:30, over 6 months. Day hospital was staffed by a multidisciplinary team of four psychiatric nurses, an occupational therapist, a nursery nurse, a lead psychiatric consultant, two clinical assistants and a senior registrar.
Petrou et al 29	Women who were at high risk of developing postnatal depression at 26–28 weeks of gestation n=151.	UK	Prevention Counselling and support delivered by trained health visitors during home visits at 3, 7 and 17 days postdelivery, then weekly up to 8 weeks postnatally.
Morrell et al 30	Women registered with participating general practitioner practices who became 36 weeks pregnant during the recruitment phase of the trial, had a live baby and were on a collaborating health visitor’s (HV) caseload for 4 months postnatally n=4084.	UK	Screening and treatment HV training in the assessment of postnatal women, combined with either cognitive behavioural approach or person-centred approach sessions (once per week for up to 8 weeks) for eligible women, plus the option of a selective serotonin reuptake inhibitor—commencing around 8 weeks postnatally.
Stevenson et al 31	Women with postnatal depression (Edinburgh Postnatal Depression Scale>12) n=not reported (model).	UK	Treatment Hypothetical group cognitive behavioural therapy (gCBT) intervention, one 2-hour session per week for 8 weeks, 4–6 women per group.
Dukhovny et al 35	Any postpartum women in seven health regions across Ontario n=610.	Canada	Prevention Telephone-based volunteer lay/peer support—at least four phone calls starting 48–72 hours after randomisation and continuing through the first 12 weeks after birth.
Ride et al 34	First-time mothers who had recently given birth and attended one of 48 participating Maternal and Child Health Centres n=359.	Australia	Prevention Psychoeducational programme targeted at the partner relationship, management of infant behaviour and parental fatigue, delivered as a one-off 6-hour session by nurses based at Maternal and Child Health Centres.
Grote et al 32	Women at 12–32 weeks gestation, scoring 10 or higher on the PHQ-9 or with a diagnosis of probable dysthymia n=270.	USA	Treatment Collaborative care for depression including a choice of brief interpersonal psychotherapy (eight initial sessions plus maintenance sessions through baby’s first year), pharmacotherapy, or both, coordinated by Depression Care Specialists (master’s-level social workers) in collaboration with obstetric care providers.
Wilkinson et al 33	Hypothetical cohort of pregnant women experiencing one live birth over 2 years n=1000.	USA	Screening and treatment Over first year post partum, general physicians screening for and treating postpartum depression and psychosis in partnership with a psychiatrist.