Background: The revised version of the Beck Depression Inventory (BDI-II) is a broadly used instrument for assessing the severity of depression of adolescents of at least 13 years of age and adults. The self-assessment questionnaire contains 21 polytomous items and follows the criteria for a major depression specified in the DSM-IV. Clinical samples have often been used to analyze the psychometric properties of the instrument primarily with factor analytic methods.
Methods: The present study performs a psychometric analysis in a non-clinical sample in order to ascertain, whether the instrument performs equally well with the different kinds of samples. A clinical sample and a sample of students filled in the questionnaire. A partial credit model was applied and parameter estimates and model fit of the two samples were compared.
Results: Threshold parameters and model fit largely agreed, however some items exhibited characteristic deviations. Nevertheless, person parameter estimates notably agreed in both samples.
Conclusions: These results indicate that the BDI-II performs in clinical and non-clinical samples comparably well, only some items show characteristic deviations in the non-clinical sample.