The Use of the PHQ9 self-rating scale to assess depression within Primary Care.

The PHQ-9 is effective in screening patients for depressionas well as monitoring progress in a variety of situations. Using the PHQ-9 after a pre-assessment with the PHQ-2 increases its specificity, as well as preventing under-diagnosis. Although it is not suitable as a stand-alone tool for a diagnosis, it is a cost-effective, efficient method of screening patients in primary care.