Depressive disorders are common in women of reproductive age and may begin during pregnancy or the postpartum period. Prevalence estimates in developed countries range from 1.0% to 5.6% for major depression alone and from 6.5% to 12.9% for major and minor depression at different points in pregnancy through 12-months postpartum. Studies focusing on the first 3-months postpartum show higher rates: 7.1% for major depression alone and 19.2% for major and minor depression combined.1
Screening pregnant and postpartum women for depression satisfies the criteria established by the World Health Organization to guide policy-makers on the value of population-based screening.2 Depression is burdensome to public health—it has a negative impact on physical and emotional well-being, relationships, work, and quality-of-life. Screening is likely to detect depression that would otherwise go undiagnosed due to its nonspecific symptoms and insidious onset. The natural history of the illness is understood—depression is more likely to persist and worsen than to resolve without treatment. Effective screening tools and treatments exist that are acceptable to patients. And, most importantly, screening programs for pregnant and postpartum women reduce the relative risk of continued depression at 3 to 5 months by 18% to 59% as compared with usual care.3 After briefly reviewing the diagnostic criteria for common forms of depression in women this article will review screening tools, approaches, and guidelines for pregnant and postpartum women. Barriers to screening and novel approaches worthy of consideration will be highlighted.
Definitions and Diagnostic Criteria
Screening tests are evaluated against a diagnostic gold standard. For depressive disorders the gold standard is a structured interview that will reveal all of the components defined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).4 Screening tools for depression focus on major depressive disorder (MDD), which is distinct from premenstrual dysphoric disorder, persistent depressive disorder (dysthymia), and depression due to another medical disorder or induced by medications or other substances. MDD subtypes include onset during pregnancy or within 4 weeks after delivery (peripartum depression) and a variety of other subtypes based on prominent features (anxiety, melancholia, catatonia, atypical mixed) or timing (seasonality). Pregnant women can be found to have preexisting MDD, new onset depression in the peripartum period, or incident depression later in the postpartum period. The definitions that follow demonstrate what diagnostic information may be missed by screening tools for the depressive disorders most commonly found in women, potential leading to what may be falsely regarded as a positive result of screening.
Diagnosing MDD requires the presence of at least 5 of 9 symptoms present during the same 2-week period, including the hallmark symptoms of depressed mood or markedly reduced interest or pleasure (anhedonia) most of the day, nearly every day. The other 7 symptoms are thoughts of worthlessness or guilt, sleep disturbance, significant change in appetite or weight, impaired concentration or memory, fatigue or lack of energy, psychomotor agitation or retardation observed by others, and recurrent thoughts of death or suicide. Collectively the symptoms must cause clinically significant distress or psychosocial impairment. Accurate diagnosis requires additional evaluation to rule out a precipitating event or loss, the presence of medical conditions (eg, hypothyroidism, diabetes mellitus) or use of medications and other substances that produce depressive symptoms, and the presence of manic or psychotic symptoms.
Distinguishing postpartum blues from depression is important for preventing overtreatment. “Postpartum blues,” “maternity blues,” or “baby blues” refers to a common and self-limited experience of depressed mood with onset 1 to 5 days after delivery and lasting <2 weeks. Severe postpartum blues can mimic depression, so patients who screen positive within the first postpartum week should be followed expectantly to prevent overdiagnosis and overtreatment.
Distinguishing postpartum depression from a psychotic episode is important for avoiding undertreatment. “Postpartum psychosis” is not recognized in DSM-5. Instead, patients with mood disorders (MDD, bipolar disorder) and psychotic symptoms developing within 4 weeks after delivery would receive the appropriate diagnosis “with peripartum onset.” From a clinical standpoint several features distinguish psychosis from depression: acute onset, rambling speech, disorganized thoughts, delusional thoughts, and hallucinations. Patients with peripartum psychotic depression have a higher risk of suicide and infanticide than depressed patients without psychosis, and thus warrant more intensive treatment including hospitalization. Women who screen positive for postpartum depression should also be screened for the presence or psychotic symptoms, with appropriate referral as needed for diagnosis and treatment.
The ideal screening test is inexpensive, easy to administer, and causes minimal discomfort to patients. Important statistical properties include high reliability (consistency across testing situations) and validity (ability to distinguish depressed from nondepressed patients). A diagnostic clinical interview is the gold standard for establishing a diagnosis of MDD and postpartum depression. Comparing a screening test result with the gold standard allows investigators to calculate test accuracy (proportion of screened population with true positive and true negative results), sensitivity (proportion of depressed patients detected by a positive screening test) and specificity (proportion of nondepressed patients detected by a negative screening test). The false positive rate is the proportion of patients who screen positive but are not depressed. Lowering the diagnostic threshold of a screening test improves test sensitivity while increasing the false positive rate.
Because questionnaires, and not laboratory tests, are used to screen for depression additional factors influence their reliability and validity. The number and complexity of screening questions may prove challenging to answer by patients with low literacy. Questionnaires administered by interview may challenge the patient’s sense of privacy and confidentiality, as compared with self-administration. If a questionnaire in the patient’s primary language is unavailable, their responses may be framed by a limited understanding of the English language. The patient’s trust in the confidentiality of her responses may also be influenced by her overall trust in the health care system and her specific health care providers. These complexities favor the use of short, self-administered tools with questions that are clearly worded in the patient’s primary language and can be completed in a private setting.
Screening Tools for Depression in Pregnancy and the Postpartum Period
Table 1 lists key characteristics of recommended screening tools for depression in pregnancy and the postpartum period. The Edinburgh Postnatal Depression Scale (EPDS), and the Postpartum Depression Screening Scale (PDSS) were developed specifically for postpartum depression and validated in perinatal populations.6 The EPDS was introduced in 1987 as a screening tool in ambulatory settings and has been used extensively in the US and Spanish-speaking countries. It includes 10 questions regarding symptoms in the past week and can be completed in <5 minutes. Studies validating the EPDS compared different score thresholds (from 9 to 13 points) against a gold standard interview and found the expected trade-offs. The most commonly used threshold scores are ≥10 or ≥12 points. Lower thresholds increase test sensitivity while decreasing specific and increasing false positive screening results.7 Developed initially in 2000 the PDSS includes 35 items and can be completed in 5 to 10 minutes and is available in Spanish. Items assessing MDD symptoms and other elements characterizing postpartum depression are included in the questionnaire’s 7 domains: sleeping/eating disturbances, anxiety/insecurity, emotional lability, mental confusion, loss of self, guilt/shame, and suicidal thoughts. Sensitivity and specificity are within the range of other screening tools. A threshold score of 60 is a positive screen for major or minor postpartum depression, and a score of 80 defines a positive screen for major postpartum depression. The higher threshold has lower sensitivity (more false positives).8
Classifying peripartum depression as a variant of major depression spurred evaluation of MDD screening tools that were initially developed for the general population.9 The Patient Health Questionnaire (PHQ) was introduced in 1999 as a self-administered version of a validated tool (PRIME-MD). The PHQ-9 assesses the frequency of all the MDD symptoms in the past 2 weeks (scored from 0 to 3) and is closely aligned with current diagnostic criteria. The PHQ-9 was validated in large samples of women before it was tested for use in pregnancy and the postpartum period. The threshold score of 10 (of 27 possible points) is a positive screening result for at least mild depression, and a score of 20 is consistent with severe depression.
The Beck Depression Inventory (BDI) was developed in 1961 and updated (BDI-II) in 1996 to reflect the revised depression diagnostic criteria in the Fourth edition of the DSM. It includes 21 items in which patients select 1 of 4 first-person statements that best fits how they feel today. Each item is scored from 0 to 3 and there are 63 total points possible. The threshold scores are 14 for mild depression, 20 for moderate depression, and 29 for severe depression.
The Center for Epidemiologic Studies Depression Scale (CES-D) was developed in 1977 as a tool for population-based research. It includes 20 items assessing mood symptoms in the past week. Each item is scores from 0 to 3 and there are 60 points possible. A score of ≥15 is the screening threshold for depression risk.
The Zung Self-Rating Depression Scale was developed in 1965. It includes 20 positive and negative statements answered on 4-point Likert scales. The screening threshold is 50 (of 80 possible points) and severe depression is more likely when the score is at least 70.
The screening questionnaires for depression are more common than they are different. All are self-administered and can be completed in <10 minutes, with the majority taking ≤5 minutes. A Spanish-language version exists or is in development for all of the questionnaires, and all versions use language that is accessible to patients of low literacy. All but the CES-D have been used to monitor symptoms in published studies of depressed patients.
Limited evidence from comparative studies does not find one tool to be superior to the others for optimizing sensitivity while minimizing false positive results. On the basis of accessibility, tools such as the EPDS and PHQ-9 are preferable because they are shorter, accessible by website and smartphone applications, available in multiple languages, and inexpensive. A systematic review in 2013 identified only 11 studies evaluating the sensitivity and specificity of commonly used tools.6 A head-to-head comparison of EPDS and PHQ-9 administered with 185 pregnant and postpartum women showed both tools had comparably high sensitivity, specificity, and predictive capabilities. EPDS was evaluated in 11 studies, PDSS in 4 studies, BDI in 4 studies, PHQ-9 in 1 study, Zung in 1 study, and CES-D in 1 study. Most studies reported high sensitivity and specificity (80% to 90%). Lower thresholds increased sensitivity but also increased the rate of false positives. All positive screening results should be followed by an interview to confirm the frequency and severity of symptoms, address safety risks, screen for symptoms of mania and psychosis, and evaluate the patient for chronic conditions, medications, and other substances that can produce depressive symptoms.
In the past several years several organizations have updated their screening guidelines for depression in pregnancy and the postpartum period. The American College of Obstetricians and Gynecologists (ACOG) recommends screening for depression and anxiety at least once during the perinatal period using a validated, standardized tool.5 In 2013 ACOG convened a Well-Woman Task Force to develop a consensus among 15 leading professional associations representing women’s health clinicians from obstetrics and gynecology, pediatrics, primary care, and nursing backgrounds. The Task Force recommended annual and postpartum depression screening using a validated tool.10 In 2016 the US Preventive Services Task Force (USPSTF) completed an extensive evidence review and recommended screening for depression in the general adult population, including pregnant and postpartum women. The recommendation’s “B” grade indicates high certainty of at least moderate benefit from depression screening. Importantly, USPSTF underscored that for screening to be effective, adequate systems must exist to ensure accurate diagnosis, effective treatment, and appropriate follow-up.11 Taken together these recommendations form a consensus that patients entering pregnancy should be screened for depression unless they have already been screened in the past year, and then screened again for postpartum depression.
Barriers to Screening and How to Overcome Them
Barriers to successful screening include patient, clinician, and system factors. Stigma, time constraints, and lack of motivation are the most frequent barriers reported by patients.12 Clinician and system barriers include time pressures, difficulty identifying accurate assessment tools and interpreting their results, poorly defined referral pathways, and inadequate community mental health services.13 The USPSTF cites availability of effective treatment and follow-up care as prerequisites for effective depression screening.11 Screening programs that address patient, clinician, and system factors together seem to create better outcomes than programs that focus on only 1 or 2 factors.14,15
Two universal screening programs used different strategies to address barriers successfully. Kaiser Permanente Northern California used a quality improvement process to introduce universal screening over several years throughout their system of 15 obstetrical hospitals.16 Patients were screened using PHQ-9 at prenatal intake, 24 to 28-week gestation, and 3 to 8-week postpartum. Facility champions were appointed to lead training efforts at their hospitals so clinicians would have the necessary skills and resources to assess, diagnose, and treat patients with a positive screening test. Workflow improvements and use of electronic health records facilitated screening and clinical monitoring. Referrals were made to mental health providers if clinically indicated and acceptable to the patient. In total, 54% (3% of 5.6%) who screened positive for severe depression were subsequently diagnosed with moderate to severe depression. Of diagnosed patients 80% were treated 40% met the goal of at least 50% improvement, and 25% had a clinical remission of depression symptoms.
Obstetrical leaders at Massachusetts General Hospital transitioned a targeted screening program to universal screening after mandatory statewide reporting was introduced in 2010.17 All obstetrical patients in the 2 largest outpatient prenatal clinics were screened using EPDS at 24 to 28-week gestation and 6-week postpartum. Licensed clinical social workers (LCSWs) stationed in the clinics evaluated all screen-positive patients and triaged them to care by an LCSW, clinical psychologist, or psychiatrist. Among the women who screened positive 67% were subsequently diagnosed with MDD, 37% were diagnosed with an anxiety disorder, and 28% were diagnosed with both. Approximately one third of screen-positive patients were subsequently treated with antidepressant medication.
Comparing the 2 screening programs allows identification of common themes and different approaches that produced successful outcomes (Table 2). The Kaiser Permanente Northern California program empowered and trained care providers across a large network to interpret PHQ-9 screening results, make diagnoses, and arrange or prescribe treatment, with judicious use of mental health resources. The Massachusetts General Hospital program embedded mental health professionals in obstetrical clinics to interpret EPDS screening test results, make diagnoses and triage patients to care by an LCSW, clinical psychologist or psychiatrist, mostly occurring onsite. The success of both suggests that their differences (screening using PHQ-9 vs. EPDS, reliance on empowered obstetrical clinicians vs. embedded mental health clinicians) are not as important as their similarities. The 2 programs prioritized keeping care local (which patients prefer), used system-wide screening tools, used standardized procedures for interpreting screening results and arranging subsequent care for screen-positive patients, and accessed a variety of care options that were financially and geographically accessible to patients.
Novel Screening Approaches
With its frequent visits prenatal care provides multiple opportunities to screen women for depression. However, no-show rates for postpartum visits are high in many communities. Detecting incident depression in the postpartum period may require screening in nonobstetrical settings. Visits for well-baby care or evaluation in the emergency department create new opportunities for maternal screening. A systematic review of 6 studies (variable quality) concluded that postpartum screening outcomes during well-baby visits are comparable with outcomes of postpartum screening in general.18 A Dutch study comparing usual care with postpartum screening during well-baby visits at 1-, 3-, and 6-month postpartum showed a marked reduction in depression diagnosed at 9 months in the screened group.19 Postpartum screening is also feasible in pediatric emergency departments (16% positive screening).20 In total, 28% of mothers of infants admitted to the hospital screened positive for postpartum depression, and <15% reported they had been screened for depression previously.21 The EPDS is the most commonly used screening tool in these studies. PHQ-2 and PHQ-9 have also been used successfully.22
E-screening using computer technology allows validated printed tools to be completed privately with immediate scoring and interpretation using systematic algorithms. A Canadian randomized trial enrolling over 600 pregnant women showed a greater preference for use of a computer tablet than a written questionnaire regarding emotional health issues. E-screening participants felt this approach was more confidential, faster, and less impersonal than paper-based screening.13
Universal screening for depression in pregnancy and the postpartum period is critical for improving detection and facilitating treatment. On the basis of the successful programs described previously, all pregnant patients should be routinely screened in the third trimester and again in the postpartum period. Additional screening should be considered at the first prenatal visit if not done in the previous year. Effective screening tools include those developed specifically for postpartum depression, such as EPDS, and screening tools for MDD that have been evaluated in pregnant and postpartum women, such as PHQ-9. Universal screening programs for depression during pregnancy and the postpartum period can successfully overcome patient, clinician, and system barriers to reduce the burden of disease. Components common to successful programs include the use of clear clinical pathways for diagnosis and treatment, and use of the electronic health record to facilitate screening and symptom monitoring. Implementation of universal screening should be a priority for all health systems providing obstetrical care.
1. Gavin NI, Gaynes BN, Lohr KN, et al. Perinatal depression
: a systematic review of prevalence and incidence. Obstet Gynecol. 2005;106(pt 1):1071–1083.
2. Wilson JMG, Jungner G. Principles and Practice of Screening
for Disease. Geneva: World Health Organization; 1968.
3. O’Connor E, Rossom RC, Henninger M, et al. Primary care screening
for and treatment of depression
in pregnant and postpartum women: evidence report and systematic review for the US Preventive Services Task Force. JAMA. 2016;315:388–406.
4. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th ed. Arlington, VA: American Psychiatric Association; 2013.
5. American College of Obstetricians and Gynecologists Committee on Obstetric Practice. Screening
for perinatal depression
. Committee Opinion No. 630. Obstet Gynecol. 2015;125:1268–1271.
6. Myers ER, Aubuchon-Endsley N, Bastian LA, et al. Efficacy and Safety of Screening for Postpartum Depression Comparative Effectiveness Review 106
[(Prepared by the Duke Evidence-based Practice Center under Contract No 290-2007-10066-I) AHRQ Publication No 13-EHC064-EF]. Rockville, MD: Agency for Healthcare Research and Quality. 2013.
7. Cox JL, Holden JM, Sagovsky R. Detection of postnatal depression
: development of the 10-item Edinburgh Postnatal Depression
Scale. Br J Psychiatry. 1987;150:782–786.
8. Beck CT, Gable RK. Postpartum Depression Screening
Scale: development and psychometric testing. Nurs Res. 2000;49:272–282.
9. Williams JW Jr, Pignone M, Ramirez G, et al. Identifying depression
in primary care: a literature synthesis of case-finding instruments. Gen Hosp Psychiatry. 2002;24:225–237.
10. Conry JA, Brown H. Well-Woman Task Force: components of the well-woman visit. Obstet Gynecol. 2015;126:697–701. (Supplemental Digital Content).
11. O’Connor E, Rossom RC, Henninger M, et al. Screening
in Adults: An Updated Systematic Evidence Review for the US Preventive Services Task Force: Evidence Synthesis No 128 (AHRQ Publication No 14-05208-EF-1). Rockville, MD: Agency for Healthcare Research and Quality; 2016.
12. Prevatt BS, Desmarais SL. Facilitators and barriers to disclosure of postpartum mood disorder symptoms to a healthcare provider. Matern Child Health J. 2018;22:120–129.
13. Kingston D, Austin MP, Veldhuyzen van Zanten S, et al. Pregnant women’s views on the feasibility and acceptability of web-based mental health e-screening
versus paper-based screening
: a randomized controlled trial. J Med Internet Res. 2017;19:e88.
14. Chen H, Wang J, Ch’ng YC, et al. Identifying mothers with postpartum depression
early: integrating perinatal mental health care into the obstetric setting. ISRN Obstet Gynecol. 2011;2011:309189.
15. Miller L, McGlynn A, Suberlak K, et al. Now what? Effects of on-site assessment on treatment entry after perinatal depression screening
. J Women Health. 2012;21:1046–1052.
16. Flanagan T, Avalos LA. Perinatal obstetric office depression screening
and treatment: implementation in a health care system. Obstet Gynecol. 2016;127:911–915.
17. Venkatesh KK, Nadel H, Blewett D, et al. Implementation of universal screening
: feasibility and impact on obstetric care. Am J Obstet Gynecol. 2016;215:517.e1–517.e8.
18. van der Zee-van den Berg AI, Boere-Boonekamp MM, IJzerman MJ, et al. Screening
for postpartum depression
in well-baby care settings: a systematic review. Matern Child Health J. 2017;21:9–20.
19. van der Zee-van den Berg AI, Boere-Boonekamp MM, Groothuis-Oudshoorn CGM, et al. Post-up study: postpartum depression screening
in well-child care and maternal outcomes. Pediatrics. 2017;140:pii:e20170110.
20. Emerson BL, Bradley ER, Riera A, et al. Postpartum depression screening
in the pediatric emergency department. Pediatr Emerg Care. 2014;30:788–792.
21. Trost MJ, Molas-Torreblanca K, Man C, et al. Screening
for maternal postpartum depression
during infant hospitalizations. J Hosp Med. 2016;11:840–846.
22. Gjerdingen D, Crow S, McGovern P, et al. Postpartum depression screening
at well-child visits: validity of a 2-question screen and the PHQ-9. Ann Fam Med. 2009;7:63–70.