Factor structure of the Dutch version of the Penn State Worry Questionnaire

The Penn State Worry Questionnaire (PSWQ) is a 16-item self-report scale for measuring the excessiveness and uncontrollability of worry. The current study examined the factor structure of the PSWQ in (1) a large community sample (N = 455), and (2) a clinical sample of patients with generalized anxiety disorder (GAD; N = 102), the disorder for which worry is the key feature. Confirmatory factor analysis was employed to test three models: (1) a one-factor model in which all items loaded on one and the same dimension, (2) a two-factor model in which positively and negatively worded items loaded on two separate but correlated factors, and (3) a one-factor model, that included the reverse items as a method factor. In the community sample the one-factor/method factor model provided the best fit for the data. This was also true in the clinical GAD sample, but only after error covariances between a number of items were allowed to correlate.