New PHQ-9 screening test evaluates major depression in adults

Joint UW, Seattle Children's and Group Health study is first to test PHQ-9 in teens

Primary-care clinicians know teen depression is common, but they've lacked a reliable screening test for it. Now researchers at the University of Washington (UW), Seattle Children's, and Group Health report the PHQ-9 (Patient Health Questionnaire - 9 item) is a good screening test for major depression in adolescents.

Led by Laura P. Richardson, MD, MPH, the team tested the PHQ-9 as a screening tool for depression in 442 teenage patients, age 13-17, at Group Health. The test is brief, available free of charge, easy to score and understand, and proven to find major depression (meeting DSM-IV criteria) in adults. This study, the first to assess it in teens, is in the November 2010 Pediatrics.

"This is important not only because depression is relatively common among adolescents, but also because we have effective treatment for them," said Dr. Richardson. She is an associate professor of pediatrics at the UW, an adolescent medicine specialist at Seattle Children's, and an affiliate investigator at Group Health Research Institute. "Primary care clinicians are advised to screen teens for depression," she said, "and they need a convenient tool like this."

The team compared the PHQ-9 to the more labor-intensive gold standard, an independent structured mental health interview (the Child Diagnostic Interview Schedule, DISC-IV)-and to published data on use of the screening test in adults. They found the best cut point for maximizing the PHQ-9 screening test's sensitivity without losing specificity (11) is higher among teens than in adults. But its sensitivity (89.5%) and specificity (77.5%) in teens are similar to those in adults. So the team concluded that the PHQ-9 is an excellent choice for providers and researchers who want to screen for depression in teens in primary care.