What your PHQ-9 score means
The PHQ-9 is a nine-question questionnaire about common symptoms of depression over the last two weeks [1]. This guide explains how the total is worked out, what each band means, why one question is read on its own, and where the number stops being useful.
How the total is worked out
Each question is answered on the same four-point scale, from 0 for "not at all" to 3 for "nearly every day" [1]:
- 0 for not at all
- 1 for several days
- 2 for more than half the days
- 3 for nearly every day
Add up the nine answers and you get a total between 0 and 27.
The five bands
The PHQ-9 authors set 5, 10, 15 and 20 as the lower limits of mild, moderate, moderately severe and severe depressive symptoms [1].
| Total score | Band |
|---|---|
| 0-4 | Minimal |
| 5-9 | Mild |
| 10-14 | Moderate |
| 15-19 | Moderately severe |
| 20-27 | Severe |
The bands describe how heavy your symptoms have been over two weeks. They do not say what is causing them, and they are not diagnoses.
Why 10 matters
In the original study, a score of 10 or more had a sensitivity of 88% and a specificity of 88% for major depression, among 580 patients who also had an interview with a mental health professional [1].
A much larger 2019 analysis pooled data from 58 studies and 17,357 people [2]. A cut-off of 10 gave the highest combined sensitivity and specificity, at 0.88 and 0.85 [2]. In everyday numbers:
- Of 100 people who had major depression, about 88 scored 10 or more and about 12 scored lower.
- Of 100 people who did not, about 85 scored below 10 and about 15 scored 10 or more.
So the cut-off misses some people and flags others who turn out not to have major depression. A separate pooled analysis of 44 studies found that 24.6% of people scored 10 or more, while 12.1% met interview criteria for major depression [3]. The authors concluded that a score of 10 or more substantially overestimates how common depression is [3].
That is why a score in the moderate band or above is a strong reason to talk to someone, not a finding in itself.
Question 9 is read on its own
The ninth question asks about thoughts that you would be better off dead or of hurting yourself. The PHQ-9 authors count this symptom if it is present at all, however often [1].
There is a reason for this. In a study of 84,418 outpatients, the risk of a suicide attempt over the following year rose from 0.4% among people who answered "not at all" to 4% among those who answered "nearly every day" [4]. The answer to question 9 stayed a strong predictor even after taking account of age, sex, treatment history and overall depression score [4].
So if you answered anything other than "not at all", mention it to your GP soon, even if your total is low. If the thoughts feel strong right now:
- call 999 or go to A&E if your life is at risk or you cannot keep yourself safe [6]
- in England, call 111 and select the mental health option [6]
- anywhere in the UK, call Samaritans free on 116 123, day or night [7]
Our guide to getting help in the UK lists the urgent lines for Scotland, Wales and Northern Ireland.
What a score cannot tell you
- The cause. Before making a diagnosis, a clinician is expected to rule out physical causes, normal grief and a history of manic episodes [1].
- Anything outside the last two weeks. The NHS describes depression as feeling persistently sad for weeks or months, not just a few days [5]. A two-week questionnaire cannot show that on its own.
- A diagnosis. Depression symptom questionnaires are not meant for diagnostic classification [3].
What to do with your score
Write down your total, your answer to question 9 and the date. If your score is 10 or more, or you are worried whatever the number, the NHS advises seeing a GP if you think you may be depressed [5]. In England you can also refer yourself to NHS Talking Therapies for anxiety and depression without speaking to a GP [8]. Our guide to getting help in the UK covers the other nations.
Taking the questionnaire again in a few weeks can show whether things are moving. Bring the scores with you to appointments, so you and the person you see can look at them together.