About
The Patient Health Questionnaire-9 (PHQ-9) is a clinical tool used for the screening, diagnosis, monitoring, and measurement of the severity of depression. It is applicable to the general adult population, including primary care and mental health settings. The PHQ-9 is a self-administered version of the PRIME-MD diagnostic instrument for common mental disorders, and it scores each of the nine DSM-IV criteria for major depressive disorder as "0" (not at all) to "3" (nearly every day). The clinical utility of the PHQ-9 lies in its ability to facilitate the recognition and diagnosis of depression in clinical practice, as well as monitor a patient's response to treatment. It is not only a diagnostic tool but also a severity measure, providing clinicians with a practical and validated method to quantify depression symptoms and track them over time. There are no specific exclusion criteria for the use of the PHQ-9; however, it should be noted that it is not designed to diagnose other mental health disorders, and it may not be as effective in populations with lower literacy levels due to its self-administered nature. Furthermore, it is not a substitute for a comprehensive psychiatric evaluation and should be used as an initial screening tool