[Structure and adequacy of the Beck Depression Inventory in patients with fibromyalgia].

The Beck Depression inventory is a widely used instrument for the measurement of depression in chronic pain. However, there are no studies that analyze the structure and adequacy of the use of the BDI in these patients. In this work, we have carried out exploratory and confirmatory factor analysis of the results of the BDI in a sample of 300 patients with fibromyalgia. The factor structure of the exploratory BDI yields three factors that include cognitive, emotional and somatic symptoms. The structural equation analyses carried out to confirm the fit of the data in this sample with the models of chronic pain presented in the literature were not significant. These results indicate that there are differences between the depressive manifestations of this type of patients and those with chronic pain. In addition, the peculiar structure of the BDI in this sample of patients seems to indicate an overlap between some depressive symptoms and the symptoms of fibromyalgia, which could lead to an overestimation of the occurrence of depression when measured with the BDI, a bias that should be assessed and modified.