Psychometric Properties of the Generalized Anxiety Disorder Questionnaire - IV (GAD-Q-IV) in Postpartum Mothers

Generalized anxiety disorder (GAD) is a mental disorder of which the main feature is persistent and impairing worry. GAD symptoms are common for women during the postpartum period and GAD prevalence rates have been reported as higher in postpartum mothers than in the general population. Currently, little psychometric evidence exists for a screening measure to detect the possible presence of diagnosable GAD for postpartum women. The purpose of this investigation was to gather psychometric information for the Generalized Anxiety Disorder Questionnaire–IV (GAD-Q-IV; Newman et al., 2002) with a sample of postpartum mothers. Factor analyses were conducted to determine the factor structure of the GAD-Q-IV in postpartum women. Receiver-operating characteristic (ROC) analysis was used to determine a range of potential GAD-Q-IV cut-off scores for detecting the likely presence of GAD in postpartum women. Results from this study provided evidence to justify a 1-factor structure for the GAD-Q-IV responses from postpartum women, which demonstrated structural, metric, and scalar invariance over time. Findings from these analyses provided evidence of incremental validity, as there was a significant increase in predicting GAD diagnoses when GAD-Q-IV responses were used compared with another measure of postpartum depression. Last, using ROC analysis, a range of GAD-Q-IV cut-off scores was determined, which can be applied to screening for the likely presence or absence of GAD in postpartum women. The evidence presented in this study suggests that the GAD-Q-IV could be a viable screening measure used to identify the likely presence of GAD in postpartum women so that further evaluations and treatments can be recommended.