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 nine-item questionnaire in a prospective cohort study with 135 patients who were also referred for structured clinical interviews.
These patients were among 478 patients 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 suffered 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,” Dr. Fann, of the department of psychiatry and behavioral sciences, said in an interview about the poster.
Just why this population is more vulnerable to depression is not clear, Dr. Fann said. Brain lesions could be a factor, he said, but many patients also suffer from psychosocial stressors, such as unstable employment and social support or abuse of alcohol or other substances.
Dr. Fann said the standard of care at most hospitals and rehabilitation centers is not to screen traumatic brain injury patients for depression.
The investigators were especially interested in the PHQ-9 because it has been validated for other medical conditions and would be easy for nonpsychiatrists to use. “It takes 2–5 minutes,” he said. “We did this over the phone. It can be filled out by the patients themselves with paper and pencil. Or it can be done face to face in an interview format.”
The PHQ-9 asks whether patients had been bothered during the previous 2 weeks by each of nine symptoms of major depressive disorder in the DSM-IV. The multiple-choice answers range from “not at all” to “nearly every day.”
“It has validity for major depression but also helps remind nonpsychiatrists what the DSM criteria are,” Dr. Fann said.
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 poster reported 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). The investigators also found correlations of 0.90 with the Hopkins Symptom Checklist Depression Subscale and 0.78 with the Hamilton Rating Scale.
Dr. Fann's group conducted the study at the Harborview Medical Center in Seattle, a level I trauma center serving the states of Washington, Idaho, Montana, and Alaska. They called participants at home to administer the PHQ-9 every month or two for a year after the patients were treated for a traumatic brain injury that was severe, moderate, or complicated mild.