What this quick check measures
The PHQ-4 is a four-question screening tool for the two most common mental health problems, anxiety and depression [1]. The two often happen together, and daily life tends to be harder when they do [1].
It is built from two shorter questionnaires [1][2]:
- Two anxiety questions (the GAD-2): feeling nervous, anxious or on edge, and not being able to stop or control worrying [3].
- Two depression questions (the PHQ-2): feeling down, depressed or hopeless, and having little interest or pleasure in doing things [3].
All four ask how often each problem has bothered you over the last two weeks [3].
Who developed it
The PHQ-4 was put together by Kurt Kroenke, Robert Spitzer, Janet Williams and Bernd Löwe and published in 2009 [1]. They tested it with 2,149 patients from 15 primary care clinics [1]. The questions split cleanly into two groups, depression and anxiety, and higher scores were strongly linked with problems in daily life, days lost to disability and use of health care [1].
It was then checked in a face-to-face household survey of 5,030 people in Germany [2]. That study is useful because it shows how the general public scores, not only people at a clinic.
How the PHQ-4 is scored
Each question is scored from 0 to 3 [3]:
| Answer | Points |
|---|---|
| Not at all | 0 |
| Several days | 1 |
| More than half the days | 2 |
| Nearly every day | 3 |
You get three numbers.
1. Total score (0 to 12). The four answers add up to a total that is rated in four bands [3]:
| Total score | Rating |
|---|---|
| 0-2 | Normal |
| 3-5 | Mild |
| 6-8 | Moderate |
| 9-12 | Severe |
2. Anxiety score (0 to 6). The first two questions. A score of 3 or more suggests anxiety [3].
3. Depression score (0 to 6). The last two questions. A score of 3 or more suggests depression [3].
The two part scores matter most for what to do next. A total of 4 could be all anxiety, all depression or some of each.
How your score compares with the general public
In the German survey, a depression score of 3 matched a percentile rank of 93.4%, and an anxiety score of 3 matched 95.2% [2]. A score of 5 matched 99.0% for depression and 99.2% for anxiety [2]. In other words, most adults score below 3 on each part.
What your result can and cannot tell you
The PHQ-4 is a sorting tool. It can show whether anxiety, depression or both are worth a closer look. It cannot diagnose either, and it cannot show how severe a problem is in any detail. With only two questions for each, it also misses some people.
How accurate is it?
Each half has been tested on its own.
- Depression questions (PHQ-2). In the original study of 580 patients who were also interviewed by a mental health professional, a score of 3 or more had a sensitivity of 83% and a specificity of 92% for major depression [4]. A 2020 review of 100 studies and 44,318 people found a sensitivity of 0.72 and a specificity of 0.85 at the same score [5].
- Anxiety questions (GAD-2). A 2016 review of six samples found a sensitivity of 0.76 and a specificity of 0.81 for generalised anxiety disorder at a score of 3 [6].
So the quick check picks up most people with significant symptoms, but not all. A low score is reassuring, but if you still feel unwell, take that seriously. The German survey did not include a diagnostic interview [2], so its percentiles describe how people score, not who has a condition.
What to do next in the UK
- If both parts are under 3 and you feel you are coping, take the check again if things change.
- If the anxiety part is 3 or more, take the GAD-7 anxiety test on this site. The NHS suggests seeing a GP if you think you might have generalised anxiety disorder [8].
- If the depression part is 3 or more, take the PHQ-9 depression test on this site. The NHS advises getting help from a GP if you think you may be depressed [7].
- In England, you can refer yourself to NHS talking therapies for anxiety and depression without speaking to a GP [9]. You need to be 18 or over (16 or 17 in some areas) and live in England, and you do not need a diagnosis [10].
- In Scotland, your GP practice is the first place to go when it is open [12].
- In Northern Ireland, your GP may treat you directly or refer you to mental health services [15].
- In Wales, your GP can refer you to local primary mental health services, which then have a duty to assess you [18].
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 [11].
- England: call 111 and select the mental health option [11].
- Scotland: phone NHS 24 on 111 and choose the mental health option [12].
- Wales: call 111 and press option 2. It is free and open 24 hours a day, 7 days a week, for all ages [13].
- Northern Ireland: call Lifeline on 0808 808 8000. It is free and open 24 hours every day [14].
- Anywhere in the UK: call Samaritans free on 116 123, day or night [16], or text the word SHOUT to 85258 for free text support at any time [17].