Patient Health Questionnaire (PHQ-9)

While the PHQ-9 is a valuable screening tool for depression, it is not solely sufficient for a diagnosis. A full clinical assessment, along with other depression scales and other measures, is required to diagnose major depression accurately.

Yes, the PHQ-9 is both reliable and valid. Studies have shown it to be highly reliable and valid for diagnosing depression across different settings and populations. It has relatively sound psychometric properties compared to other depression screening instruments.

It typically takes about 3 to 5 minutes for a patient to complete the PHQ-9, making it a quick and efficient tool for assessing depression severity.