This article is for Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines, so you may find the language more technical than the condition leaflets.

This easy to use patient questionnaire is a self-administered version of the PRIME-MD diagnostic instrument for common mental disorders.[1] The PHQ-9 is the depression module, which scores each of the nine DSM-IV criteria as "0" (not at all) to "3" (nearly every day). It has been validated for use in primary care.[2]

It is not a screening tool for depression but it is used to monitor the severity of depression and response to treatment. However, it can be used to make a tentative diagnosis of depression in at-risk populations - eg, those with coronary heart disease or after stroke.[3, 4]

When screening for depression the Patient Health Questionnaire (PHQ-2) can be used first (it has a 97% sensitivity and a 67% specificity).[5]If this is positive, the PHQ-9 can then be used, which has 61% sensitivity and 94% specificity in adults.

Patient Health Questionnaire (PHQ-9)
Over the last two weeks, how often have you been bothered by any of the following problems?
Feeling nervous, anxious or on edge.
Not beingable to stop or control worrying
Worrying too much about different things
Trouble relaxing
Being so restless that it is hard to sit still
Becoming easily annoyed or irritable
Feeling afraid as if something awful might happen
Total = /21


GAD-7 Anxiety Severity.

This is calculated by assigning scores of 0, 1, 2, and 3, to the response categories of “not at all,” “several days,” “more than half the days,” and “nearly every day,” respectively. GAD-7 total score for the seven items ranges from 0 to 21.

Scores represent: 0-5 mild 6-10 moderate 11-15 moderately severe anxiety 15-21 severe anxiety.