Psychometric Properties of the GAD-7 among College Students: Reliability, Validity, Factor Structure, and Measurement...

The GAD-7 is a brief, freely available questionnaire measuring anxiety, which is a common mental health problem among college students. The current study examined the psychometric properties of the GAD-7 among undergraduate students from a public midwestern university (n=582; M=19.0±1.0 years-old; 79.4% women; 81.6% White) who completed the GAD-7, State-Trait Anxiety Inventory-Trait subscale (STAI-T), and Behavioral Inhibition/Activation Scale-Reward subscale (BIAS-R). The psychometric properties of two GAD-7 models were examined: a one-factor model, equivalent to a single total score, and a two-factor model, including cognitive-emotional and somatic tension factors. The GAD-7 total score had excellent reliability (both α and ω=0.91) and evidence for convergent (r with STAI-T=0.70, p<.001) and discriminant validity (r with BIAS-R=-0.04, p=.350). The cognitive-emotional factor had excellent reliability (α=0.90; ω=0.91), whereas the somatic tension factor had adequate reliability (α=0.76; ω=0.77). Both factors had evidence for convergent validity (cognitive-emotional: r with STAT-T=0.70, p<.001; somatic tension: r with STAT-T=0.60, p<.001) and discriminant validity (cognitive-emotional: r with BIAS-R=-0.05, p=.227; somatic tension: r with BIAS-R=-0.02, p=.700). Confirmatory factor analyses supported both the one-factor model (RMSEA=.098, CFI=.994) and the two-factor model (RMSEA=.069, CFI=.997), albeit with a high inter-factor correlation (r=.91). Measurement invariance was supported across gender, race/ethnicity, and college class for both models. The findings support using the GAD-7 total score among U.S. college students, as is common in practice, but also provided evidence for the two-factor model in this population. Considering its parsimony, the total score would be preferable in applied settings for a quick measurement of anxiety symptom severity.