GAD-7 score interpretation: what each score range means

GAD-7 score ranges at a glance

GAD-7 score interpretation starts with the four ranges set out by Spitzer and colleagues in the Archives of Internal Medicine in 2006: 0–4 minimal, 5–9 mild, 10–14 moderate and 15–21 severe anxiety. The total is the sum of seven items, each scored 0 to 3 for how often the patient was bothered over the last 2 weeks, so it runs from 0 to 21. The paper proposed that cut points of 5, 10 and 15 might be read as mild, moderate and severe levels of anxiety, and the PHQ and GAD-7 instruction manual repeats them. The ranges are more than labels. In the 2006 primary care study, each step up was linked with worse function on all six scales of the SF-20 health survey and with more disability days and physician visits over the previous 3 months. The table below gives those figures for each range, from the paper's analysis of patients grouped by score, with the number of patients in each group.

Disability days and physician visits cover the previous 3 months. On the SF-20 mental health scale, a higher score means better function.

Four totals worked by hand show how answers map onto the ranges. Use the GAD-7 calculator to check any set of answers.

GAD-7 score of 0 to 4: minimal anxiety

A GAD-7 score of 0 to 4 sits below the mild cut point of 5, and Spitzer 2006 labels this range minimal in its tables. It was the most common range in the study: 1,182 primary care patients fell in it, more than in the other three ranges together. Those patients had the best function, with a mean SF-20 mental health score of 82, and reported 3.9 disability days over the previous 3 months. Scores in this range are also typical of the general population. In a nationally representative household survey of 5,030 people in Germany, Löwe and colleagues (Medical Care, 2008) found mean GAD-7 scores of 3.2 in women and 2.7 in men. Among the primary care patients in Spitzer 2006 who did not have generalized anxiety disorder on interview, the mean score was 4.9, at the top of this range. A low total makes generalized anxiety disorder unlikely, but the GAD-7 asks only about anxiety, so it says nothing about depression or other problems.

GAD-7 score of 5 to 9: mild anxiety

A GAD-7 score of 5 to 9 marks mild anxiety in Spitzer 2006 and in the PHQ and GAD-7 instruction manual, and it sits below the usual screening cut-off of 10. In the 2006 study, 511 patients scored in this range. Their mean SF-20 mental health score was 65, against 82 in the minimal range, and they reported 7.5 disability days and 1.7 physician visits over the previous 3 months, nearly double the 3.9 disability days of the minimal group. In the same study, a cut-off of 8 had a sensitivity of 92% and a specificity of 76% for generalized anxiety disorder, and a cut-off of 9 had 90% and 79%. A 2016 meta-analysis by Plummer and colleagues, covering 11 samples for this question, found pooled sensitivity of 83% and specificity of 84% at a cut-off of 8, and judged cut-offs from 7 to 10 acceptable. A score of 8 or 9 can therefore still come from a patient with the disorder.

GAD-7 score of 10: what the screening cut-off means

A GAD-7 score of 10 is the cut-off Spitzer 2006 chose for identifying probable generalized anxiety disorder, the point that best balanced a sensitivity of 89% and a specificity of 82% against a mental health professional's telephone interview in 965 patients. A score of 10 also opens the moderate range, 10 to 14. The PHQ and GAD-7 instruction manual calls 10 a yellow flag, drawing attention to a possible clinically significant condition, and recommends 10 or more as the cut point for further evaluation when screening for anxiety disorders. A score of 10 is a reason to assess, not a diagnosis. In the primary care sample, 23% of patients scored 10 or more, while Kroenke and colleagues found generalized anxiety disorder in 7.6% of the interviewed patients, so at this cut-off the positive predictive value was 29% and the negative predictive value 99%. A positive screen may instead reflect panic disorder, social anxiety disorder or post-traumatic stress disorder, which the GAD-7 also picks up.

Put the other way round, 89% of patients with generalized anxiety disorder scored 10 or more, so about 1 in 9 scored below it, and 82% of patients without the disorder scored under 10. At 10 or more the positive likelihood ratio was 5.1. The 264 patients in the moderate range had a mean SF-20 mental health score of 54 and reported 10.7 disability days and 2.2 physician visits over the previous 3 months. Patients with generalized anxiety disorder on interview had a mean GAD-7 score of 14.4, at the top of the moderate range.

GAD-7 score of 15 to 21: severe anxiety

A GAD-7 score of 15 to 21 is the severe range, and the PHQ and GAD-7 instruction manual calls 15 a red flag, a level at which active treatment is probably warranted. The cut point of 15 maximized specificity in the 2006 study: 95% of patients without generalized anxiety disorder scored below it, and the positive likelihood ratio was 8.7. Sensitivity fell to 48%, so fewer than half the patients with the disorder reached this range, and a score under 15 does not mean the anxiety is mild. The 171 patients in the severe range had the worst function on every SF-20 scale, including a mean mental health score of 41, and reported 16.8 disability days and 2.4 physician visits over the previous 3 months, more than four times the disability days of the minimal range. Severe scores are uncommon outside the clinic: Löwe 2008 found that about 1% of the German general population scored 15 or more, and about 5% scored 10 or more.

How much a change in GAD-7 score matters

A change in GAD-7 score over time is easier to read once you know how large a change counts. Toussaint and colleagues (Journal of Affective Disorders, 2020) followed 261 patients from a multisite trial of chronic depression at baseline, 12 weeks and 48 weeks. GAD-7 scores fell significantly in patients who improved on the Hamilton Rating Scale for Depression, rose in those who worsened, and did not change significantly in those whose depression stayed the same. The authors estimated the minimal clinically important difference at 4 points on the GAD-7 total. A fall from 12 to 8, for example, is a change of that size, and it also moves the score from the moderate range into the mild one. The authors asked for confirmation in trials focused on anxiety treatment, and the PHQ and GAD-7 instruction manual notes that the GAD-7 had shown change as a secondary outcome in depression trials but had not yet been studied as a primary outcome in anxiety trials.

Use the same questionnaire wording at each visit, and enter each set of answers in the GAD-7 calculator to compare the totals and ranges side by side.