• A 9-item screening measure devised to identify probable major depressive disorder (MDD) among adult primary care patients.

Clinical Considerations

  • Can be used as a tool to screen for major depression
  • Corresponds with the DSM-IV criteria

ICF Domain

Body Function – Subcategory: Mental Functions


  • Self-report; can also be done in interview format
  • Items are rated in terms of how persistent the symptoms have been in the past 2 weeks: 0 – not at all, 1 – several days, 2 – more than half of the days, 3 – nearly every day.
  • Administration time is approximately 5 minutes.

Number of Items





The score for each individual item is summed to produce a total score.


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# of studies reporting psychometric properties: 5


MCID: not established for the SCI population, but for a sample of older primary care patients (n = 434, mean age = 71 (7.4) years, all participants enrolled in the Improving Mood-Promoting Access to Collaborative Treatment (IMPACT)):

MCID = 5 points

Reference: Lowe, B., Unutzer, J., et al. (2004). “Monitoring depression treatment outcomes with the patient health questionnaire-9.” Med Care 42(12): 1194-1201.

SEM: not established for the SCI population, but for a sample of older primary care patients (see Lowe et al. 2004 reference above): SEM for change due to treatment and no control of prior depression = 2.44 SEM for the same number of DSM-IV depressive symptoms at both assessments = 1.32

MDC: not established

  • Higher scores indicate increased severity of depression.
  • A cut-off score of 10 has been reported to indicate major depression.
  • Published data for the SCI population is available for comparison (see the Interpretability section of the Study Details sheet).


Internal consistency for the overall PHQ-9 scale was reported to be High (Cronbach’s a=0.83-0.89).

[Bombardier et al. 2004, Richardson and Richardson 2008, Graves & Bombardier 2008, Krause et al. 2009]


  • Correlation of the PHQ-9 is:
    • High with the Older Adult Health and Mood Questionnaire (Spearman’s r=0.781)
    • Moderate with major depressive disorder (MDD) (Spearman’s r=0.530)
    • Moderate with the Satisfaction with Life Scale (Spearman’s r=-0.477).
  • PHQ-9 scores were inversely and Moderately correlated with subjective health on the SF-1 (Spearman’s r=0.37).
  • For a 3-item screening test with a score cutoff of 3, a sensitivity of 0.87 and specificity of 0.93 were reported; with a score cutoff of 4, a sensitivity of 0.82 and a specificity of 0.95 were reported.
  • For the total PHQ-9, a cutoff of 11 was determined to have optimal diagnostic accuracy of MDD. At this cutoff, the PHQ-9 detected 100% (sensitivity) of those with a diagnosis of MDD and had a specificity of 84%.

[Bombardier et al. 2004, Bombardier et al. 2012, Richardson and Richardson 2008, Krause et al. 2009]


No values were reported for the responsiveness of the PHQ-9 for the SCI population.

Floor/ceiling effect

No values were reported for the presence of floor/ceiling effects in the PHQ-9 for the SCI population.


Dr. Vanessa Noonan, Kyle Diab

Date Last Updated

Mar 16, 2017

Bombardier CH, Richards JS, Krause J, Tulsky D, Tate D. Symptoms of Major Depression in People With Spinal Cord Injury: Implications for Screening. Arch Phys Med Rehabil 2004;85:1749-1756.

Bombardier CH, Kalpakjian CV,  Graves DE, Dyer JR, Tate DG, Fann JR. Validity of the Patient Health Questionnaire-9 in assessing major depressive disorder during inpatient spinal cord injury rehabilitation. Arch Phys Med Rehabil, 2012; 93(10):1838-1845.

Graves DE and Bombardier CH. Improving the efficiency of screening for major depression in people with spinal cord injury. J Spinal Cord Med. 2008; 31(2): 177-84.

Krause JS, Saunders LL, Reed KS, Coker J, Zhai Y, Johnson E. Comparison of the Patient Health Questionnaire and the Older Adult Health and Mood Questionnaire for self-reported depressive symptoms after spinal cord injury. Rehabilitation Psychology, 2009; 54(4): 440-448.

Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16(9):606-13.

Richardson EJ and Richards JS. Factor structure of the PHQ-9 screen for depression across time since injury among persons with spinal cord injury. Rehabilitation Psychology, 2008; 53(2):243-249.

Williams RT, Heinemann AW, Bode RK, Wilson CS, Fann JR, Tate DG. Improving measurement properties of the Patient Health Questionnaire-9 with Rating Scale analyses. Rehabilitation Psychology 2009; 54(2): 198-203.