The PHQ-9 is a nine-question screening and monitoring tool for depression. Each question corresponds to one of the nine diagnostic criteria for major depressive disorder: low mood, loss of interest, sleep changes, fatigue, appetite changes, feelings of worthlessness, trouble concentrating, moving or speaking slowly or restlessly, and thoughts of death or self-harm. You rate how often each has bothered you over the past two weeks, from not at all (0) to nearly every day (3). The total ranges from 0 to 27. Scores of 5, 10, 15 and 20 mark the thresholds for mild, moderate, moderately severe and severe depression.
The PHQ-9 was developed in the late 1990s and is free to use, which is why it appears in primary care offices, hospitals and psychiatry clinics worldwide. It takes about two minutes. It is not a diagnosis on its own; a clinician still confirms the picture through an interview. Its real value is tracking. Repeating it at each visit shows whether a medication or therapy is working, whether you have reached remission (generally a score below 5), or whether a change is needed. The ninth question, about thoughts of being better off dead, is reviewed at every visit regardless of total score. At Stedfast Psychiatry you will complete a PHQ-9 at your first appointment and at follow-ups, in person or through the patient portal before telehealth visits.