The patient health questionnaire-9 (PHQ) [
depression, depressive symptoms, depressive, depressive disorders
The PHQ is a nine-item depression scale. It is based directly on the diagnostic criteria for major depressive disorders in the Diagnostic and Statistical Manual Fifth Edition. The PHQ scores range from 0 to 3 from not at all to nearly every day, respectively. It has five ranges of severity, i.e., minimal depressive symptoms, mild depressive symptoms, moderate depressive symptoms, moderately severe depressive symptoms, and severe depressive symptoms. The scores on this self-report measure do not provide a diagnosis on their own as a diagnosis necessitates a detailed clinical investigation. PHQ reliability estimation is 0.89.