The Accuracy of the PHQ-2 Alone and Combined With the PHQ-9 to Identify Major Depression in Traumatic Brain Injury.

Objective: To assess the reliability, construct validity, and screening accuracy of the Patient Health Questionnaire-2 (PHQ-2) and the combined PHQ-2/PHQ-9 to detect major depressive disorder (MDD) in persons with traumatic brain injury (TBI).

Setting: Level 1 trauma center.

Participants: Participants were 135 adults within 1 year of sustaining complicated mild, moderate, or severe TBI, initially recruited for a depression treatment trial.

Design: Screening validity study relative to structured diagnostic assessment.

Interventions: Not applicable.

Main measures: PHQ-2 and PHQ-9 depression scales, Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.

Results: The optimal cutoff for the PHQ-2 alone is a score of 2 or more which results in a sensitivity of .86 and a specificity of .83. When the PHQ-2 and PHQ-9 are combined in a 2-step process, the optimal cutoffs are 1 or more on the PHQ-2 and a total of 5 or more of the 9 PHQ-9 symptoms endorsed at least several days in the past 2 weeks. This resulted in a sensitivity of .93 and a specificity of .89 and only 53.6% of patients needed to be administered the entire PHQ-9.

Conclusion: The 2-step PHQ-2/PHQ-9 screening process described here represents an efficient, reliable, and valid means of detecting MDD in people with TBI. Results suggest that the generic PHQ-2/PHQ-9 depression screening parameters adopted within large U.S. federal entities may disadvantage people with TBI.