The first Spanish adaptation of the Beck Depression Inventory-II (BDI-II) was published in 2011. This year marks the 50th anniversary of the publication of its first edition. In this time, the BDI has become the most widely used self-report instrument for assessing the severity of depression in Spain and worldwide. This paper presents the basic characteristics of the BDI-II in relation with its previous versions (BDI-I and BDI-IA), describes the process of its adaptation to the Spanish population, summarizes the psychometric properties of this adaptation, and discusses its use in the clinical practice. To this use, guidelines and cut-off scores are proposed for measuring the severity of depression, for evaluating the clinical significance of therapeutic change, for screening for depression, and for aiding in the differential diagnosis of depressive disorders
