PHQ-9 Detects Depression After Traumatic Brain Injury

Abstract

SANTA ANA PUEBLO, N.M. — The Patient Health Questionnaire is a simple, reliable tool that any clinician can use to screen patients for depression after traumatic brain injury, Dr. Jesse R. Fann reported at the annual meeting of the Academy of Psychosomatic Medicine. Dr. Fann and his colleagues at the University of Washington, Seattle, validated the questionnaire in a prospective cohort study with 135 patients, also referred for structured clinical interviews. These patients were among 478 enrolled at the time of analysis in a National Institutes of Health-supported study that is using the PHQ-9 to determine the prevalence of depression in people who have had traumatic brain injury. “Various studies have estimated 25%–45% get depressed in the first year. The prevalence drops after the first year, but remains significantly higher than the general population,” said Dr. Fann. It is not clear why this population is more vulnerable to depression. But brain lesions could be a factor.Many patients also suffer from psychosocial stressors. The investigators were especially interested in the PHQ-9 because it has been validated for other medical conditions and is easy for nonpsychiatrists to use. The PHQ-9 asks if patients experienced in the prior 2 weeks each of nine symptoms of major depressive disorder in the DSM-IV. The study found the optimal criterion for a positive screen on the PHQ-9 to be a patient reporting five or more of the nine symptoms for at least several days. The researchers specified that one of these five symptoms should be a cardinal symptom: either depressed mood or anhedonia. When patients met the optimal criterion, the PHQ-9 had a maximum sensitivity of 0.93, maximum specificity of 0.89, positive predictive value of 0.63, and negative predictive value of 0.99 in comparison to a Structured Clinical Interview for DSM-IV (SCID). There also were correlations of 0.90 with the Hopkins Symptom Checklist Depression Subscale and 0.78 with the Hamilton Rating Scale. The group conducted the study at the Harborview Medical Center in Seattle, a level I trauma center. They administered the PHQ-9 every month or two for a year after patients were treated for a traumatic brain injury that was severe, moderate, or complicated mild. The 135 patients in the validation study had a mean age of 42. About 70% were male, and 90% were white. Vehicular accidents were the most common cause of injury (41.5%), followed by falls (33.3%).