Simple strategy effective in postpartum depression screening

Medical Tribune February 2009 P16
David Brill

Combining two existing screening tools could be a straightforward, time-saving and effective way to detect postpartum depression (PPD) in primary care, US research has shown.

The first screening stage, comprising two simple yes/no questions, was 100 percent sensitive at detecting PPD, according to the Annals of Family Medicine study. [2009; 7:63-70]

Patients with a positive result on the two-question screen should then progress onto the nine-item Patient Questionnaire (PHQ-9), say the University of Minnesota researchers, who report that this second stage was 92 percent specific. They tested the two-tiered strategy in 506 women who brought their newborn infants for well-child visits at pediatric and family medicine clinics over the course of 9 months.

The screening tools have already been incorporated into routine practice at several Minnesota clinics and are soon to be implemented in three large hospitals, according to Dr. Dwenda Gjerdingen, who led the study.

“We find them easy to administer, patients find them easy to complete, and they give us a good sense of where the patient is at in terms of their mental health,” she said.

“You want your initial screen to be highly sensitive, which this one is: the two-question screen does not miss depressed patients. Then the PHQ-9 is a very specific test so when depressed people complete it and it turns out to be positive, it is likely to be a true positive and not a false positive.”

The two-question screen focuses on the main symptoms of depression: diminished mood and loss of pleasure in activities.

Despite the common nature of PPD – the condition affects around 22 percent of new mothers and is the most common complication of childbirth – less than half of mothers are presently being screened, the authors wrote. The condition not only affects the mother’s wellbeing but can also harm the cognitive development of the infant. [Arch Womens Ment Health 2003 Nov;6(4):263-74]

The results of the new strategy were validated against the Structured Clinical Interview from the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV. Forty-five (8.9 percent) of the women were found to have major depression.

Gjerdingen noted that the PHQ-9 still missed a few depressed patients, so suspicion should be retained in those who achieve a negative result having scored positively on the initial two-question screen. These women should be advised to see their doctor if they experience a dip in mood, she said.

Both the two-question screen and the PHQ-9 are already used in general depression but had yet to be validated in PPD. Other potential screening options for PPD are available but typically take longer to complete, Gjerdingen said.