The Patient Health Questionnaire (PHQ-9) is a self-administered tool that assesses the severity of depression. It's a part of the larger Patient Health Questionnaire (PHQ), which is a three-page instrument that can evaluate eight diagnoses. The PHQ-9 is a nine-item questionnaire that incorporates the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria for major depressive disorder (MDD). It also includes other major depressive symptoms.

After selecting a value for each item you will be presented with a series of recommendations to aid in managing your depression.