Comorbid Posttraumatic Stress Symptoms in an Urban Population of Mothers Screening Positive for Depression FREE

Screening for maternal depression in clinical and community settings has been the topic of numerous recent studies and an important component of the 2009 Institute of Medicine report Depression in Parents, Parenting, and Children.¹ According to the report, however, studies of maternal depression screening have largely ignored the implications of comorbid mental health conditions on screening approaches and evaluation of screening effectiveness.¹ One condition that may accompany—and complicate—maternal depression is posttraumatic stress disorder (PTSD).

Posttraumatic stress disorder and depression share several diagnostic criteria, and depression—when accompanied by posttraumatic stress symptoms—is less responsive to treatment.² Whereas depression has an extensive evidence base for effective primary care–based treatment, PTSD typically requires mental health specialty services. In certain high-risk populations, therefore, it is important to understand the likelihood with which depression screening instruments identify mothers who may have PTSD.

We surveyed mothers of children aged 0 to 5 years from Women, Infants, and Children offices and Head Start centers in a single city. Research assistants approached all mothers in Women, Infants, and Children office waiting rooms; Head Start mothers were recruited through flyers and by Head Start staff unaware of the study's specific purpose. Ability to communicate in English or Spanish was the eligibility criterion.

Respondents answered a face-to-face questionnaire, which included the Patient Health Questionnaire–2 and the Modified PTSD Symptom Scale. The Patient Health Questionnaire–2 is a 2-item depression screening instrument with performance characteristics of 83% sensitivity and 92% specificity for major depression.³ The Modified PTSD Symptom Scale is a valid scale of PTSD symptomatology.⁴ Consistent with previous literature,⁵ we created a proxy variable for PTSD diagnosis by mapping individual Modified PTSD Symptom Scale items onto Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) diagnostic criteria. Data analysis was composed of descriptive statistics. The Boston Medical Center institutional review board approved this study.

From a total sampling frame of 5426 mothers, we surveyed 190 mothers. One hundred ten (58%) reported English as their primary language; 55 (30%), Spanish. Seventy-seven women (41%) self-identified as black and 75 (39%) as Latina. On average, the mothers had 2.16 children (SD, 1.27); most mothers were younger than 30 years old; and 43% worked outside the home.

Of 190 mothers, 56 (29%) screened positive for depression and 32 (17%) had symptoms consistent with DSM-IV criteria for PTSD. Of the 56 women with positive depression screens, 14 (25%) had symptoms consistent with PTSD. Thirty-one women had both positive depression screens and reported histories of trauma; of these, 45% had symptoms consistent with PTSD.

In our sample, 89 women (47%) reported having an unusually traumatic event in their lifetime. The most common traumas were sexual assault, physical assault, witnessing someone shot or killed, and witnessing the death of a family member. Among those having experienced a trauma, 32 (36%) had symptoms consistent with PTSD.

A screening test is indicated if it accurately identifies a condition, which can then be treated effectively. According to the US Preventive Services Task Force, adult depression fits these criteria, provided that appropriate systems exist to ensure accurate diagnosis and appropriate follow-up and treatment.⁶ However, when depression is comorbid with posttraumatic stress symptoms—as it appears to be in 25% of our sample—it is both more difficult to diagnose and more refractory to treatment. Among populations in which this comorbidity is highly prevalent, depression may no longer fit the paradigm for a good screening test, given current screening practices and availability of services.

To fulfill the US Preventive Services Task Force's criteria for diagnostic accuracy and appropriate follow-up and treatment, therefore, it may be that maternal depression screening in certain settings ought to be augmented with additional questions around trauma exposure or symptomatology and that more detailed screening—accompanied by algorithms for referral—may be warranted. Given the limited mental health resources for low-income populations, the high prevalence of maternal depression, and the benefits to children of treating depressed mothers, resolving these issues is of substantial public health importance.

Correspondence: Dr Silverstein, Boston Medical Center, 88 E Newton St, Vose 3, Boston, MA 02118 (michael.silverstein@bmc.org).

Author Contributions: Dr Silverstein had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Silverstein and Feinberg. Acquisition of data: Silverstein, Feinberg, Sauder, Egbert, and Stein. Analysis and interpretation of data: Silverstein and Feinberg. Drafting of the manuscript: Silverstein and Sauder. Critical revision of the manuscript for important intellectual content: Silverstein, Feinberg, Egbert, and Stein. Statistical analysis: Silverstein. Obtained funding: Silverstein and Feinberg. Administrative, technical, and material support: Silverstein, Feinberg, Sauder, Egbert, and Stein. Study supervision: Silverstein and Feinberg.

Funding/Support: Dr Silverstein is supported by grant K23MH074079 from the National Institute of Mental Health, grant R03HD058075 from the National Institute of Child Health and Human Development, the Hood Foundation, and the Robert Wood Johnson Foundation under its Physician Faculty Scholars Program.

Financial Disclosure: None reported.

Additional Contributions: Barry Zuckerman, MD, and Howard Bauchner, MD, reviewed the manuscript.