This review found no evidence that biological interventions (antidepressant drugs, hormones and supplements) administered during pregnancy or after birth were effective in preventing postnatal depression. The review had methodological weaknesses, but the author’s conclusions reflected the limited evidence found and seem likely to be reliable.

To review the evidence for effectiveness of biological interventions for preventing postpartum depression.

MEDLINE/PubMed, CINAHL, PsycINFO, EMBASE, ProQuest, The Cochrane Library and World Health Organization Reproductive Health Library were searched. Search terms were reported. Contents of key journals and reference lists of included studies and relevant reviews were also examined. English language studies published between 1966 and 2003 were included.

Research studies of biological interventions for the prevention of postpartum depression were eligible for the review. Postpartum depression was defined as inception of depression within the first year after childbirth. To be included, studies had to evaluate an outcome measure of postpartum depression beyond the first postpartum week.

Biological interventions were not defined explicitly, but included studies that evaluated antidepressants, hormones and supplements (calcium and docosahexaenoic acid). Interventions were administered during pregnancy or after birth. Depression was evaluated using a variety of scales.

The author stated neither how the papers were selected for the review nor how many reviewers performed the selection.

Studies were assessed using the criteria of the Canadian Task Force on Preventive Health Care. Study quality was classed as good, fair or poor using study design-specific criteria. The author did not state how many reviewers performed the validity assessment.

The author stated neither how the data were extracted for the review nor how many reviewers performed the data extraction.

Data were synthesised narratively by type of intervention. The synthesis was limited by the fact that only one study was found for most interventions.

Seven studies were included: five random controlled trials (n = 1,594); one quasi-experimental study (n = 23); and one uncontrolled study (n = 11). Four studies were rated fair quality and three poor. None of the studies provided sufficient evidence to recommend use of the intervention. The quasi-experimental study compared postpartum antidepressants plus monitoring with monitoring alone in women with a history of postpartum depression. The antidepressant group had a significantly reduced recurrence of depression. One random controlled trial of postpartum progestogen therapy found a significantly increased risk of depression in the intervention group.

No specific biological approach to preventing postpartum depression can be strongly recommended for clinical practice.

This review had broad inclusion criteria for participants, interventions and outcomes. No inclusion criteria were specified for study design, so the review was not limited to the most relevant evidence. The search covered a wide range of relevant sources. Limiting the search to English language studies could have resulted in relevant studies being missed. Unpublished studies were not sought and risk of publication bias was not evaluated. Validity of included studies was assessed and the results used in the synthesis. Relevant details of included studies were presented, although discrepancies between the text and reference list meant it was not always clear which study was being referred to. The processes used for study selection, validity assessment and data extraction were not reported. If only the single named author was involved, there would be no mechanism for minimising possible errors or subjective decisions. A narrative synthesis was appropriate, but its usefulness was limited by the small number of studies found. Despite the methodological limitations of the review, the author's conclusions reflected the limited evidence found and seem likely to be reliable.

Practice: The author stated that there was insufficient evidence to recommend any biological intervention for use in routine clinical practice.

Research: The author stated that further rigorous RCTs were required to evaluate antidepressants, hormonal interventions and calcium supplementation. Studies should involve women from a range of ethnic and socioeconomic backgrounds.

Toronto Public Health.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.