The PHQ-9 is a validated, 9-item self-administered scale measuring the degree of depressive symptoms (based on DSM-IV criteria) over the last two weeks. It also includes an (unscored) item to measure their impact. It is commonly used both for screening and monitoring purposes.
Created by Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues, with an educational grant from Pfizer Inc. No permission required to reproduce, translate, display or distribute.
Self-report scales are for screening purposes only, and must be interpreted by a qualified health professional in conjunction with clinical assessment. They cannot be used alone for diagnostic or treatment purposes.