Distinguishing anxiety and depression in self-report: purification of the Beck Anxiety Inventory and Beck Depression Inventory-II.

The overlap of symptoms associated with anxiety and depressive disorders hinders their differentiation using self-report scales. The aim of this study was to develop purified versions of the Beck Anxiety Inventory (BAI) and the Beck Depression Inventory-II (BDI-II) that encompass only items highly specific to anxiety and depression, respectively. However, using these purified scales only increased the ability to differentiate anxiety and depressive disorders slightly. Anxiety and depression seem to be inherently linked and, thus, the high comorbidity of anxiety and depressive disorders seems to be not a function of the same types of symptoms being reported for each disorder. Nevertheless, purified BAI and BDI-II scales might be useful for separating the effects of interventions on anxiety and depressive symptoms. (c) 2010 Wiley Periodicals, Inc.