Validity, Reliability, and Optimal Cut-off Scores of the WHO-5, PHQ-9, and PHQ-2 to Screen Depression Among University Students in Iran

This study aimed to investigate the validity, reliability, and optimal cut-off points for the Patient Health Questionnaire-2 (PHQ-2), Patient Health Questionnaire-9 (PHQ-9), and Well-being Index (WHO-5) to screen mild depression among 400 Iranian students who completed these tools and Beck Depression Inventory (BDI-13). Further, a psychiatrist diagnosed the depression by using the “Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders.” The validity and internal consistency of tools assessed and the accuracy were computed using the receiver operating characteristic (ROC) and area under the curve (AUC). The internal consistency values of PHQ-2, PHQ-9, and WHO-5 were .73, .88, and .94, respectively. The PHQ-2 (.53), PHQ-9 (.60), and WHO-5 (.54) were significantly associated with the BDI. The PHQ-2, PHQ-9, and WHO-5 had optimal cut-off points of 2, 5, and 9 with an AUC of .809, .851, and .823, respectively. Based on these findings, it is recommended to use the PHQ-9 for mild depression screening among medical university students in Iran because of its high sensitivity and specificity.