Comparison of depressive indices: reliability, validity, relationship to anxiety and personality and the role of age and life events.

Introduction: Although a great number of depressive scales were developed during the last decades, there are only a few studies that compare them in terms of reliability and validity. The current study aimed to compare the properties of some of the most popular of these scales.
Materials and Methods: The study sample included 40 depressed patients 29.65+/-9.38 years old, and 120 normal comparison subjects 27.23+/-10.62 years old. The clinical diagnosis was reached by consensus of two examiners with the use of the SCAN v.2.0. The scales compared were the CES-D, ZDRS, BDI-I, and the KSQ. The STAI, the Life Change Scale (Holms and Rahe), and the EPQ were also administered. The analysis included the comparison of psychometric properties and the use of Pearson correlation coefficient and factor analysis.
Results: The results suggested that no scale was clearly superior to the others. All scales correlated to anxiety measurements, sociodemographic variables, personality dimensions and non-specific indices. The results reported here include an appendix with algorithms that help transforming one scale score into other scales scores. These algorithms can be useful for comparison purposes in meta-analytic studies.
Discussion: The comparison of several depressive scales provided no impressive results on the superiority or inferiority of a specific scale in comparison to the others.