Sexuality and gender invariance of the PHQ-9 and GAD-7: Implications for 16 identity groups

Background: The Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7 (GAD-7) are two commonly used screening tools for depression and anxiety, respectively. Despite the widespread use of these instruments, researchers have yet to examine whether scores may differ as a function of gender identity or sexuality orientation. Method: Using data from the 2018 and 2019 National Healthy minds study (N = 46,672), the present study tested each instrument for measurement invariance across 16 gender and sexual minority groups. Results: Multigroup structural equation modeling revealed that several sexual minority groups evidenced questionable fit indices for both measures. Gay men, questioning women, and queer men had unacceptable fit indices for the PHQ-9. Only cisgender heterosexual men and women evidenced residual invariance on the PHQ-9. All gender minority groups evidenced significantly higher factor loadings for item 9 (the self-harm indicator) for the PHQ-9. Most identity groups evidenced scalar or partial scalar invariance for the GAD-7; however, no groups evidenced residual invariance on the GAD-7. Limitations: Findings may not generalize to non-college student populations. Conclusions: Researchers should weight means when conducting between group comparisons for groups that failed scalar invariance. Gender and sexual minorities may have inflated scores using the PHQ-9 and GAD-7 cut-offs.