Patient Health Questionnaire-9 (PHQ-9)

Nine experiences make up the questionnaire: little interest or pleasure in doing things; feeling down, depressed or hopeless; trouble with sleep; feeling tired or having little energy; poor appetite or overeating; feeling bad about oneself; trouble concentrating; moving or speaking noticeably slowly or restlessly; and thoughts of being better off dead or of self-harm. Each is rated by how often it has occurred over the past two weeks, from not at all to nearly every day. Together the items describe the core of a depressive episode: low mood and lost interest, accompanied by changes in the body, in thinking and in self-regard.

Kroenke, Spitzer and Williams (2001) developed the questionnaire as the depression module of the Patient Health Questionnaire, a self-report version of an earlier clinician-administered primary care interview. Each item corresponds to one of the nine symptom criteria for a major depressive episode in the Diagnostic and Statistical Manual of Mental Disorders (DSM), which allows the same brief form to serve both as a screen and as a measure of severity.

The nine ratings are summed into a single total. Lower totals indicate that depressive symptoms have been occasional or absent over the past two weeks; higher totals indicate symptoms that have been frequent and, at the upper end of the range, present on most days. The report places the total within the published severity bands and describes what that range tends to mean. A high score is a reason for a fuller conversation with a qualified clinician, and any endorsement of the final item, about thoughts of death or self-harm, deserves prompt attention whatever the total.

The questionnaire is used to screen for depression in medical and mental health settings, to monitor change during treatment, and as an outcome measure in research. On this site it pairs naturally with the GAD-7 for anxiety symptoms, the WHO-5 Well-Being Index, which approaches mood from the side of positive well-being, the Edinburgh Postnatal Depression Scale (EPDS) for the period around childbirth, and the Depression Anxiety Stress Scales (DASS-21).

Convergently/construct-wise, as PHQ-9 severity increased, functional status declined on all six SF-20 subscales, with the strongest association to SF-20 mental health (r = .73) and progressively smaller associations to general health (.55), social functioning (.52), role functioning (.43), physical functioning (.37), and bodily pain (.33); symptom-related difficulty, sick days, and health-care utilization also rose with severity (Kroenke et al., 2001). Discriminantly, associations with physical-function and pain scales were weaker than with mental-health functioning, consistent with a depression-severity rather than general-medical-complaint instrument. A positive screen indicates need for clinical follow-up, not a diagnosis by itself.

At the published cutoff sensitivity and specificity for major depression are both about 0.88 (Kroenke et al., 2001).

“Little interest or pleasure in doing things”

Illustrative only. During administration items are presented one screen-set at a time; response-key direction is never shown to respondents.

Item responses are summed to a total score and compared against published screening cutoffs.

The report explains which published screening bands your score falls in and what they mean.