Validation of the Patient Health Questionnaire-9 and the Generalized Anxiety Disorder-7 in Lithuanian individuals with anxiety and mood disorders

The Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) are short self-report questionnaires used to screen and assess depression and anxiety severity in medical and community samples. However, little is known about their psychometric properties in individuals with anxiety and mood disorders (AMD) This study evaluated the psychometric properties of the PHQ-9 and GAD-7 in individuals with AMD. Individuals (n = 244, mean age 39.9 ± 12.3 years) with AMD completed the PHQ-9, GAD-7, as well as other measures of depression, anxiety, and a structured diagnostic interview. The PHQ-9 and GAD-7 demonstrated good internal consistency (Cronbach's alpha 0.87 and 0.84, respectively). The PHQ-9 and GAD-7 showed a weak correlation with clinician-rated scales HAM-D and HAM-A (r = 0.316, p < 0.01, r = 0.307, p < 0.01, respectively). For the PHQ-9, a cut score of ≥11 resulted in 72% sensitivity and 72% specificity at recognizing depression symptoms. For the GAD-7, a cut score ≥7 resulted in 73% sensitivity and 54% specificity at recognizing any anxiety disorders. The confirmatory factor analysis suggested a two-factor structure (“cognitive/affectional”, “somatic”) for both the PHQ-9 and GAD-7. In conclusion, the PHQ-9 and GAD-7 have adequate formal psychometric properties as severity measures for symptoms of anxiety and depression in individuals with AMD. The PHQ-9 performs well as a screener using a cut score of ≥11. However, the clinical utility of the GAD-7 as a diagnostic tool for recognition of anxiety disorders is limited.