Estudo de fidedignidade e validade do inventário de depressão de Beck–II (BDI-II) em adolescentes

The Beck Depression Inventory, originally from the United States, has been used worldwide for more than 40 years and throughout this time has been considered as an excellent instrument for measuring the severity of depressive symptoms in both clinical and non-clinical samples. In 1996, the Inventory authors decided to revise it in order to better adjust it to the diagnostic criteria described in the Diagnostic and Statistical Manual of Mental Disorders – Fourth Edition (DSM–IV). This revision resulted in a second edition for the instrument: the Beck Depression Inventory–II (BDI–II). Knowing the significant importance of investing in the study of a well-known and valued instrument, both by clinical and research professionals, which has been presenting good results in the scientific community in several countries, the overall goal of the present research is to contribute for the adaptation of the Beck Depression Inventory–II (BDI–II) to the Brazilian culture. In order to accomplish this goal, two study sections were developed: a theoretical one and an empirical one. The theoretical section refers to a review of the studies about the criteria which determine the depression diagnostic and its symptoms intensity. It has been discussed that it is relevant and important to perform a detailed analysis of the individuals’ answers to the instruments that provide a quantitative score. Different levels of depression intensity can be better understood from a more detailed examination of each of the scale items which represent the constellation of depression. When well studied and observed, these are important sub-clinical indicators that may lead to the understanding of a more serious difficulty than the person might be presenting. The empirical section brings up a transversal quantitative study which focuses on the investigation of the psychometric properties of the BDI-II in adolescents. More specifically, a study of reliability was performed, which focused on the evaluation of the internal consistency and on the temporal stability of the Inventory. The validity study comprised the verification of the construct validity through a correlation with the Beck Hopelesseness Scale (BHS) and in the factorial validity. The sample had the participation of 391 teenagers from the general population, males and females, coming from the junior and senior high school of public and private schools in the city of Porto Alegre, their ages ranging from 13 to 19 years old. A personal and socio-demographic data form was used for the sample characterization, as well as the BDI–II and the BHS. The results show that the Instrument, regarding its reliability, has a high level of accuracy to measure depression intensity (Cronbach Alpha = 0,86) and remains stable in its answering pattern throughout the time (r=0,87; p=0,000). Regarding the construct validity study, a positive and significant correlation was obtained in a moderate level to the BHS (r= 0,60; p=0,000). The factorial validity brought out four factors, which explain for the 47% of the total variance. The results obtained in this study corroborate the good BDI–II psychometric performance and contribute for making available, in the Brazilian market, instruments qualified for the local culture.