Screening for perinatal depression: is it enough?

Questions about current social circumstances and stressors, social and family support are also needed

Mental health problems in women during the perinatal period (from conception until the end of the first postnatal year) may cause significant morbidity and adversely affect the development of their children,1 possibly mediated by stress‐related epigenetic changes or impairment of the mother–infant relationship. Identifying and treating women with mental health problems during the perinatal period, a time when they are in regular contact with health care professionals, is accordingly important.

Screening with the Edinburgh Postnatal Depression Scale (EPDS) has been introduced as part of routine antenatal care. The EPDS was originally designed to identify postnatal depression,2 but is now also used to identify depression and anxiety during pregnancy. Screening is recommended in many guidelines and jurisdictions, including in Australia;3 further, obstetricians are being encouraged to undertake screening with increased benefits under the Medicare Benefits Schedule (MBS).

Although screening is recommended in Australia, not all women are screened, as reported by San Martin Porter and colleagues4 in this issue of the Journal. They note that the screening rate has, however, increased over time. Of concern is the fact that many of the women who did not complete the screening questionnaire in their study were at particular risk of depression: Indigenous Australians, women born overseas, older women, and women who were either single or separated. The lower screening rates in the private sector identified by the authors reflect the situation before the MBS rebates for obstetricians were improved.

Screening during the perinatal period has, importantly, raised awareness about the importance of identifying maternal mental illness and the impact it can have on the infant. But it is not enough.

Screening is only a first step in providing mental health care for women. While screening rates may be useful indicators, the more crucial questions are whether appropriate pathways of care (with adequate staffing) are available to follow up women identified as being at risk, whether women accept follow‐up, and whether screening improves outcomes.5

Identifying women at higher risk of depression (those who score 13 or more on the EPDS) should trigger a comprehensive biopsychosocial psychiatric assessment.6 This is essential because the EPDS identifies women with significant symptoms which indicate that that something is awry, and what underlies these symptoms requires deeper evaluation.

Screening has some significant limitations. First, the EPDS identifies many women as being at risk because they are experiencing stress at the time they complete the questionnaire in a booking‐in clinic.8 It is essential that the questionnaire is repeated two weeks later to check whether a woman's score remains high.9 Conducting a full evaluation because of a high score on a single assessment would unnecessarily burden limited resources.

Second, the EPDS will not identify women who have more severe mental disorders, such as schizophrenia or bipolar disorder. These women often have major difficulties after giving birth, including relapses of their mental illness, and doctors should specifically ask about these disorders. Further, the EPDS will not identify which women will subsequently experience a postpartum psychosis. Women who do are generally asymptomatic while pregnant and have no identifiable risk factors (but may have a family history of bipolar disorder or severe postpartum mental illness), but suddenly develop psychotic symptoms during the first 3 weeks after giving birth, a time when the disorder poses the most serious threat to their newborn child.

Third, depressive symptoms will often arise in women with severe personality disorders.10 These women will have the greatest difficulties in forming healthy attachments to their babies, leading to substantial problems with parenting. Focusing on depressive symptoms in women with serious personality disorders will not deal with the complex problems that underlie the woman's depression and her difficulties with the mother–infant relationship.

In addition to the EPDS, screening should therefore also include questions about current social circumstances and stressors, social and family support, and current or past treatment for mental illness (Box). Importantly, such enquiries should be made not only at the booking in visit when the EPDS is completed, but also at regular intervals throughout the perinatal period.