What this depression test measures
The PHQ-9 is a nine-question questionnaire about how often you have been bothered by common symptoms of depression over the last two weeks [1]. Each question matches one of the nine symptoms that clinicians look for when they assess major depression [1].
The questions cover:
- little interest or pleasure in doing things
- feeling down, depressed or hopeless
- sleep problems, either too little or too much
- feeling tired or having little energy
- poor appetite or overeating
- feeling bad about yourself
- trouble concentrating
- moving or speaking slowly, or being unusually restless
- thoughts that you would be better off dead or of hurting yourself
Who developed it
The PHQ-9 was developed by Kurt Kroenke, Robert Spitzer and Janet Williams and published in 2001 [1]. It was tested with 6,000 patients in 8 primary care clinics and 7 obstetrics and gynaecology clinics [1]. The authors designed it to do two jobs: help identify depression and grade how severe the symptoms are [1].
How the PHQ-9 is scored
Each of the nine questions has four answers, scored from 0 to 3 [1]:
| Answer | Points |
|---|---|
| Not at all | 0 |
| Several days | 1 |
| More than half the days | 2 |
| Nearly every day | 3 |
The points add up to a total between 0 and 27. The authors set 5, 10, 15 and 20 as the starting points for mild, moderate, moderately severe and severe symptoms [1]:
| Total score | Severity |
|---|---|
| 0-4 | Minimal |
| 5-9 | Mild |
| 10-14 | Moderate |
| 15-19 | Moderately severe |
| 20-27 | Severe |
A final question asks how difficult these problems have made it to work, look after things at home or get along with other people [1]. It is not one of the nine scored questions, but it is worth noting, because it shows how much the symptoms are getting in the way of daily life.
The question about self-harm
Question 9 asks about thoughts of being better off dead or of hurting yourself. The PHQ-9 authors count this symptom if it is there at all, however often it happens [1]. If you gave any answer other than "Not at all", please talk to someone today, even if your total is low. The section at the end of this page lists who to contact in each part of the UK.
What your result can and cannot tell you
Your score shows how much depression symptoms have bothered you over the last two weeks. That is useful. It gives you a number to take to an appointment and a way to see whether things change over time.
It cannot diagnose a depressive illness. The PHQ-9 is a screening questionnaire, not a diagnosis. Before reaching a diagnosis, a clinician is expected to rule out physical causes of the symptoms, as well as normal grief and a history of manic episodes [1]. A questionnaire cannot do that.
The NHS describes depression as more than feeling unhappy or fed up for a few days. It means feeling persistently sad for weeks or months [3].
How accurate is it?
In the original study, 580 patients also had a separate interview with a mental health professional [1]. A score of 10 or more had a sensitivity of 88% and a specificity of 88% for major depression [1]. A larger 2019 analysis pooled data from 58 studies and 17,357 people, and found a sensitivity of 0.88 and a specificity of 0.85 at the same cut-off [2].
In plain terms, two things follow:
- A high score often turns out not to be major depression. In the original study, only 31% to 51% of people above the cut-off had major depression on interview, depending on which cut-off was used [1].
- A low score does not rule a problem out. About 12 in every 100 people who did have major depression scored below 10 [2]. If you still feel unwell, take that seriously.
These figures come from clinics and research studies where people were also interviewed by a professional [1][2]. They describe the questionnaire, not any single website.
What to do next in the UK
- If your score is in the minimal or mild range and you had no thoughts of self-harm, keep an eye on how you feel. You can take the test again in a few weeks to see if anything has changed.
- If your score is 10 or more, or you are worried whatever the number, speak to your GP. The NHS advises getting help from a GP if you think you may be depressed [3]. Take a note of your answers.
- In England, you can also refer yourself to NHS Talking Therapies for anxiety and depression without seeing a GP first [4]. You need to be 18 or over (16 or 17 in some areas) and live in England, and you do not need a diagnosis to refer yourself [5].
- In Scotland, your GP practice is the first place to go when it is open [7].
- In Northern Ireland, your GP may treat you directly or refer you to mental health services [10].
- In Wales, your GP can refer you to local primary mental health services, which then have a duty to assess you [13]. Our guide to getting help in the UK covers the routes in each nation in more detail.
If you need help now
- If your life or someone else's is at risk, or you cannot keep yourself safe, call 999 or go to A&E [6].
- England: call 111 and select the mental health option [6].
- Scotland: phone NHS 24 on 111 and choose the mental health option [7].
- Wales: call 111 and press option 2. It is free and open 24 hours a day, 7 days a week, for all ages [8].
- Northern Ireland: call Lifeline on 0808 808 8000. It is free and open 24 hours every day [9].
- Anywhere in the UK: call Samaritans free on 116 123, day or night [11], or text the word SHOUT to 85258 for free text support at any time [12].