PHQ-9 is basically Sad + SIG-E-CAPS questions, scored on a scale of 0 to 3. The PHQ-9 incorporates DSM-V depression diagnostic criteria with other leading major depressive symptoms.
The PHQ-9 form should be completed by the patient and scored by the clinician. The PHQ-9 can be administered repeatedly, which can reflect improvement or worsening of depression in response to treatment.
PHQ scores ≥ 10 have a sensitivity of 88% and a specificity of 88% for major depression.
PHQ-9 scores of 5, 10, 15, and 20 represents mild, moderate, moderately severe and severe depression
PHQ-9 Form (1 page, without Instructions)
PHQ-9 Form (2 pages, with instructions)
PHQ-9 Form (3 pages, with instructions)
Sources:
http://www.phqscreeners.com/sites/g/files/g10016261/f/201412/PHQ-9_English.pdf