Scoring is easy but involves thinking about several different aspects of depression.
To use the PHQ-9 as a diagnostic aid for major depressive disorder: Question 1 or 2 needs to be endorsed as a 2 or 3. Five or more positive* answers are needed. The functional impairment question (How difficult…) needs to be rated at least as “somewhat difficult.”
To use the PHQ-9 to screen for all types of depression or other mental illness: All positive* answers should be followed by a clinical interview. A total PHQ-9 score of 10 points or more has a good sensitivity and specificity for major depressive disorder.
To use the PHQ-9 to aid in the diagnosis of dysthymia: The dysthymia question (In the past year…) should be endorsed as “yes.”
To use the PHQ-9 to screen for suicide risk: All positive answers to question 9 and the two additional suicide items must be followed by a clinical interview.
To use the PHQ-9 to obtain a total score and assess depressive severity: Add up the numbers endorsed for questions 1 to 9 and obtain a total score. See the chart below.
Total score	Depression severity

0 to 4	No or minimal depression
5 to 9	Mild depression
10 to 14	Moderate depression
15 to 19	Moderately severe depression
20 to 27	Severe depression