There is a variety of rating scales for symptoms of depression, and the 9-item Person Health Questionnaire (PHQ-9) is one of them.

The PHQ-9 article below is highly cited (more than 3600 citations as of May 2015).

The advantages of the PHQ-9 are:

  • It is a methodologically good scale (check the article)

  • It takes very little time to fill in, only 9 short questions

  • It can be used without paying a publisher/company, as is the case with the well known Beck depression inventory (BDI)

Like the CUDOS, the PHQ-9 can be used to indicate the severity of depression. The authors write:

PHQ-9 scores of 5, 10, 15, and 20 represented mild, moderate, moderately severe, and severe depression, respectively.

— Kroenke et al. (2001)
See also the CUDOS depression scale in the PsyToolkit survey library.

Run the demo

On the Kroenke et al. (2001, p.612) paper it states: "The development of the PHQ-9 was underwritten by an educational grant from Pfizer US Pharmaceuticals, New York, NY."

It seems that the PHQ-9 can be used freely for research, but as with any scale you use, you always need to acknowledge the creators.

The survey code for PsyToolkit

Copy and paste this code to your PsyToolkit account if you want to use the scale in your own online research project
scale: frequency
- {score=0} not at all
- {score=1} several days
- {score=2} more than half the days
- {score=3} nearly every day

l: phq
t: scale frequency
o: width 50%
q: Over the <b>last 2 weeks</b>, how often have you been bothered by any of the following problems?
- Little interest or pleasure in doing things
- Feeling down, depressed, or hopeless
- Trouble falling or staying asleep, or sleeping too much
- Feeling tired or having little energy
- Poor appetite or overeating
- Feeling bad about yourself - or that you are a failure or have let yourself or your family down
- Trouble concentrating on things, such as reading the newspaper or watching television
- Moving or speaking so slowly that other people could have noticed? Or the opposite - being so fidgety or restless that you have been moving around a lot more than usual
- Thoughts that you would be better off dead or of hurting yourself in some way

l: score
t: set
- sum $phq

l: feedback
t: info
q: Your score is {$score} on the Personal Health Questionnaire:<br>
You can use the table below to interprete this score.<br>
<li>A score of 5-9 points: Mild depression
<li>A score of 10-14 points: Moderate depression
<li>A score of 15-19 points: Moderately severe depression
<li>A score of 20 points and higher: Severe depression
This is simply a computer demonstration and does not replace a clinical diagnosis!<br>
If you are concerned about your mental health, make sure you seek help,<br>
for example from your doctor.<br>
If you are a student, you can contact your student services or mentor.<br>
Almost all schools and universities have a place where you can ask for help.<br>


  • Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ-9 - Validity of a brief depression severity measure. Journal of General Internal Medicine, 16, 606-613.