Postpartum Depression Screening: Importance, Methods, Barriers, and Recommendations for Practice

Depression Screening in General Populations

The published data on patient outcomes with screening for postpartum depression are limited; therefore, it is useful to review results for depression screening in general populations. In 2002, the US Preventive Services Task Force recommended routine depression screening for adults seen in practices that have systems in place to assure accurate diagnosis, effective treatment, and follow-up.⁴⁷ This B-level recommendation was based on a review of 14 randomized controlled trials on depression screening in primary care. Screening with feedback to primary care physicians increased recognition of depression 2- to 3-fold, but did not always improve patient outcomes. Studies that included screening plus collaborative or enhanced care directed at diagnosis, treatment, and follow-up showed more positive patient outcomes.³

A subsequent Cochrane review reaffirmed these findings.⁴⁸ This review included 12 trials (9 of which had been discussed in an earlier review),³ and a total of 5693 patients from nonmental health settings. Excluded from the review were trials with any modifications to usual care except screening. Screening/case finding instruments slightly improved the recognition of depression by clinicians [risk ratio (RR) 1.38; 95% CI 1.04 to 1.83]. Case recognition improved to a greater degree when clinicians were specifically informed of patients’ positive screens (RR 2.66; 95% CI 1.78 to 3.96). Unfortunately, the rate of intervention for recognized depression (eg, prescription of antidepressants) was not significantly different even with feedback (RR 1.35; 95% CI 0.98 to 1.85), and 3 of 4 studies reported no clinical effect of screening at either 6 or 12 months.⁴⁸

Therefore, primary care research has demonstrated that depression screening alone does not greatly impact outcomes. However, depression recognition is enhanced when results of positive screens are communicated to providers, and clinical outcomes seem improved when depression screening and feedback programs are coupled with systems that ensure accurate diagnosis and effective treatment and follow-up.³ Such systems require trained health professionals and office staff, collaborative working relationships between primary care and mental health providers, and case management that ensures regular follow-up and treatment compliance.

Depression Screening in Postpartum Women

Studies that have addressed postpartum depression screening demonstrate that screening is feasible in the outpatient setting and can improve the rates of detection and treatment.^{44–46, 49–51} In addition, 2 large studies (n = 860, 479) found that the vast majority of mothers (more than 80%) were comfortable with the idea of being screened for postpartum depression.^52,53 However, the rate of current screening in primary care practices is below 50% by even the most optimistic estimates.^54–56 A survey of members of the Washington Academy of Family Physicians showed that postpartum depression was considered common, serious, and treatable. Seventy percent (n = 254) of family physicians said that they always or often screened for postpartum depression at the postpartum examination, while 46% did so at well-child checkups. However, only approximately 22% overall reported using a validated tool for screening, indicating that the majority of providers who said that they screened for postpartum depression did so with either unvalidated tools or informal assessments.⁵⁵ Several studies have confirmed that informal or no assessment of potential postpartum depression is ineffective, resulting in fewer than half of cases or potential cases discovered through formal screening.^44–46,51

For clinicians who do screen for depression, the results are not always used for further documented assessment or treatment.^44,54,56 One study reported that only 23% of women with abnormal screening for depression or substance abuse had documentation of further evaluation or treatment,⁵⁴ while another study found that 60% of screen-positive women had follow-up depression evaluations and 35% were reportedly treated.⁴⁴ Therefore, even when providers routinely screen for postpartum depression with validated instruments, they do not always seem to use that information to guide clinical practice.

Failing a depression screening test should not be equated with having the condition, as only 50% of those with a positive screen actually have postpartum depression, depending on the test and cutoff score used.⁴⁸ Diagnostic evaluation should always follow screening to confirm the diagnosis.^57,58

Postpartum Depression Screening Opportunities

There are 2 convenient venues for routine depression screening in postpartum populations: mothers’ postpartum office visits and their infants’ well-child visits. Although postpartum visits are generally conducted by obstetricians, family physicians, and nurse midwives, well-child visits are usually performed by pediatricians and family physicians—79% and 19%, respectively.⁵⁹

Postpartum Visits

Postpartum depression screening at postpartum visits was studied in the primarily Caucasian population of Olmsted County, Minn. Routine screening for postpartum depression with a validated instrument, the Edinburgh Postnatal Depression Scale (EPDS), increased the rate of diagnosis of postpartum depression from 3.7% before screening to 10.7% post screening, with 19.8% of women having an abnormal screening test.⁴⁴ Treatment rates for postpartum depression also increased after the institution of formal routine screening.^44,60,61 In another study of primarily Caucasian women from the United Kingdom, 17% (30 of 176) had positive EPDS screens (score ≥12), but only 7% were perceived to be depressed by the primary health care team.⁴⁶

Higher rates of depression may be seen in low-income or ethnically diverse populations. A study of North Carolina women, 78% of whom received Medicaid, reported an increase in postpartum depression from 6.3% before routine formal screening to 35.4% using the EPDS and diagnostic evaluation.⁴⁵ Another study of mostly Hispanic and black mothers from 2 inner city practices found 22% (27 of 121) of women to have positive EPDS screens, but without use of the screening tool, providers believed that only 13% of mothers were at risk for depression.⁴⁹

One study conducted depression screening both at 28 to 32 weeks gestation and then again at 6 weeks postpartum. Of the 4038 women who were screened prenatally, 11.1% were positive (EPDS ≥12), and of the 520 screened after delivery, 7.3% were positive. The investigators of this study found that, because obstetrician/gynecologists were not comfortable diagnosing and treating depression, they had difficulty implementing postpartum depression screening until a system of referral and support was in place.⁶²

Well-Child Visits

Well-child visits provide a convenient longitudinal opportunity to screen for postpartum depression, as they occur at regular intervals throughout the first postpartum year. As with postpartum visits, screening for maternal depression during well-child visits improves the rate of depressive symptom detection, from 1.6% to 8.5% in 1 study,⁵⁰ and from 29% to 40% in another.⁵¹ Although experts have long advocated screening for postpartum depression in the pediatric setting,^63–65 most pediatric providers do not systematically do so, as evidenced by findings from the National Survey on Early Childhood Health, whereas 86.1% of the 2068 parents surveyed indicated that they had not, but should have been asked about family or psychosocial risks.⁶⁶

Providers’ reluctance to screen for postpartum depression is probably due to several factors, key among them being lack of training and experience. In a national survey of pediatricians, 57% said that they felt responsible for recognizing maternal depression, but only 32% expressed confidence in their ability to diagnose postpartum depression.⁵⁸ In another nationwide sample of general pediatricians, 49% reported little or no education on postpartum depression, and a vast majority were unfamiliar with screening tools. Less than one third of these pediatricians believed that they would recognize postpartum depression.⁶⁷ Although family physicians have training and experience with patients of all ages, less than one half (46%) of those surveyed in the state of Washington said that they always or often screened mothers for postpartum depression during well-child visits,⁵⁵ suggesting that factors other than training and experience contribute to physicians’ reluctance to screen for postpartum depression.

Other factors that compromise physicians’ recognition and management of postpartum depression are the lack of time to obtain adequate history and to educate and counsel patients.⁵⁸ This can be particularly challenging during well-child visits, when physicians are already expected to obtain expansive histories and provide anticipatory guidance around numerous health and developmental topics. Pediatricians face additional challenges, as they do not typically care for adults, and therefore are not as equipped to manage adult mental health treatment and referral. Further, given that the depressed parent is not usually under the care of the pediatrician, the provider may feel awkward and perhaps legally vulnerable at the prospect of being involved in the mother's mental health care, particularly if the mother is suicidal.

Parents and clinicians seem to agree that recognizing and dealing with postpartum depression is important in the context of primary care of the infant. However, clinicians need to be educated regarding the potential value of screening for postpartum depression during well-child visits, methods for doing so, and strategies for developing systems to manage or refer women with positive screens. Clinicians also need to be reassured that their participation in postpartum depression diagnosis and care will not have legal repercussions.

Postpartum Depression Screening Instruments

Three separate systematic reviews have been recently performed to evaluate screening tools for postpartum depression, used either in the prenatal or postpartum period. In the first review, 16 studies that used instruments prenatally to identify women who may be “at risk” for postpartum depression were included.⁶⁸ Although 16% to 52% of women in the 2 largest studies screened positive, only 8% to 35% of these identified women actually developed postpartum depression. Only 4 of the 16 studies had adequate sample sizes (n > 1300, assuming a postpartum depression prevalence of 13%) to assess the sensitivity and specificity of postpartum depression screens. Two additional problems noted were not having validated screens on separate samples (true of 4 of 6 studies with sample sizes greater than 400), and between-study variability in cutoff scores, particularly with the EPDS. The authors concluded that no screening instruments were appropriate for prenatal prediction of postpartum postpartum depression.⁶⁸ Although this review addressed the prenatal use of scales for predicting postpartum depression, these same concerns may also be applicable to postpartum screening for postpartum depression.

A second review looked at 36 studies of postpartum depression screens that met the criteria of a self report measure to assess depressive symptoms after 2 weeks postpartum, with published psychometric data on postpartum women.⁶⁹ Eight instruments were evaluated: the Beck Depression Inventory (BDI) and BDI-II, (Bromley Postnatal Depression Scale (BPDS), Center for Epidemiologic Studies Depression Scale (CES-D), Clinical Interview Schedule (CIS), Diagnostic Interview Schedule (DIS), Edinburgh Postnatal Depression Scale (EPDS), General Health Questionnaire (GHQ), Inventory of Depressive Symptomatology (IDS), postpartum depression Screening Scale (PDSS), and Zung Self-Rating Depression Scale (Zung SDS). Results of this review suggest that the EPDS is the most extensively studied postpartum measure with moderate psychometric soundness. However, most of the studies included in this review had small sample sizes, with only 6 studies including more than 400 participants, and none reaching or exceeding the sample size of 1300 participants recommended by Austin and Lumley.⁶⁸

A third review was conducted by the Agency for Healthcare Research and Quality and the Safe Motherhood Group, to determine in part the accuracy of different screening tools for detecting depression during the perinatal period.⁵ Ten studies reporting test characteristics for English-language screens were reviewed (6 of the studies had been included in the second review discussed earlier, but none had been included in the first). Again, the sample sizes were typically small (only 2 had sample sizes greater than 400), and external validity was often poor to fair (eg, most participants were white). For each of the depression screens—EPDS, BDI and BDI-II, PDSS, and CES-D—specificities were high, but sensitivities were variable. Although the EPDS and the PDSS seemed to have higher sensitivities than the BDI (with estimates ranging from 0.75 to 1.0 at different thresholds), it is difficult to know whether these are completely accurate, given the wide CIs and small sample sizes in several studies. It was recommended that future studies on perinatal depression screens must be designed with adequate sample sizes and should provide a more representative racial and ethnic mix.⁵

A newer screening tool that has gained popularity in studies on general depression, but has not yet been adequately studied in postpartum depression, is the Patient Health Questionnaire, 9-item depression module (PHQ-9), which consists of the actual criteria on which the diagnosis of major depression is based. Because of its brevity, relatively high positive predictive value (55% in primary care settings), and ability to provide information about both diagnostic criteria and depression severity, the PHQ-9 is thought by some to be the “best available depression screening tool for primary care.”⁷⁰ Although there are no readily available published reports on the validity of the PHQ-9 in screening for postpartum depression, the PHQ-9 has been effectively used as a screen in obstetrics/gynecology practices that include both women of childbearing age and older women.⁷¹ The 2-question screen, consisting of the first 2 questions of the PHQ-9 (regarding mood and pleasure), has been advocated as a quick screen. It was studied on 6000 patients in 8 primary care clinics and 7 obstetrical/gynecology clinics, where construct and criterion validity were found to be very good, and sensitivity and specificity high (83% and 92%, respectively).⁷² Some researchers recommend a 2-stage screening process, whereby patients are initially screened with the 2-question screen, and those who respond positively to either or both questions are then given a longer instrument.⁷⁰

Although several currently available depression screens have been used to identify postpartum depression in research and practice, additional studies with large, representative samples are needed to help identify the ideal postpartum depression screening tool. The “ideal” screening tool should be brief, inexpensive, easy to administer, possess a high sensitivity and good specificity, and contribute toward improved clinical outcomes.⁴⁸

Barriers and Opportunities

Previous research on depression in primary care practices has identified 3 general types of barriers to effective depression diagnosis and treatment: patient-centered, physician-centered, and systems barriers.⁷³ Patient-centered variables include cost and lack of insurance coverage,^71,74–77 time constraints,^71,77 social stigma,^71,75 nonadherence to depression treatment,⁷⁵ lack of follow-through with mental health referrals,⁷⁵ and lack of access to care for various reasons.⁷⁵ Physician centered variables include lack of time,^58,74,76 managed care policies,⁷⁴ competing demands,⁷⁵ insufficient training/knowledge,⁵⁸ insurance or payment problems, and fear of legal repercussions. Systems based variables also play a role and include infrequent follow-up visits for mothers, lack of objective, proactive monitoring of recovery, and separation of primary care and mental health services.⁷⁵

In addition, mothers of infants may experience barriers that are unique to the postpartum or early child-rearing period, such as need for childcare during mental health visits,⁷⁸ concern about medication effects on nursing infants,⁷⁹ and fear of judgment and referral to child protection.⁸⁰

Despite these numerous barriers, the opportunities afforded by postpartum depression screening and treatment are potentially vast and include not only improving the signs and symptoms of postpartum depression, but also enhancing the new mother's ability to parent, and her ability to continue to actively participate in a marriage or relationship. Recognizing and treating postpartum depression provides opportunities to decrease divorce rates, improve rates of normal child development and lower suicide and infanticide rates.^{26,28,40,81–86}