The Patient Health Questionnaire-9 (PHQ-9) is one of the most widely used tools for assessing the severity of depressive symptoms. It is a brief, 9-item questionnaire that individuals can self-administer in just a few minutes.
What is the PHQ-9?
The PHQ-9 was developed from the PRIME-MD instrument and has been validated in multiple languages and in both primary care and mental health settings.
Each of its 9 items assesses key symptoms of depression based on the diagnostic criteria of the DSM-IV.
Format: self-administered, brief (approximately 5 minutes).
Scale: from 0 (not at all) to 3 (nearly every day).
Interpretation: it allows clinicians to assess depression severity and monitor treatment response.
PHQ-2 as an initial screener
There is also a shortened version, the PHQ-2, which includes only the first two items. Its purpose is to quickly identify individuals who may need to complete the full PHQ-9.
Important considerations
The PHQ-9 is a valuable clinical tool, but it does not replace professional assessment.
It is not a general screening test.
It should not be used as the sole diagnostic criterion.
It must always be interpreted within a clinical evaluation process.
If the questionnaire indicates possible depression, or if there are thoughts of self-harm, it is essential to seek immediate help from mental health professionals or emergency services in your country.
References
- Kroenke K, Spitzer RL, Williams JBW. The PHQ-9: Validity of a Brief Depression Severity Measure. J Gen Intern Med. 2001;16(9):606–613.
- PHQ Screeners. Pfizer Inc. www.phqscreeners.com.
Download the official questionnaire
You can access the full questionnaire in this link.
