Depressive dimensions and item response analysis of the Hamilton Depression Rating Scale-17 in eating disorders.

Background: Most patients having eating disorders (EDs) experience depressive symptoms. To date, there have been few reports about the different depressive dimensions in EDs.

Objective: The aim of this study was to investigate the dimensions of depressive symptoms and highlight the distribution of the symptoms. The psychometric properties of these measures were tested using item response theory methods.

Methods: A total of 103 consecutively admitted inpatients and outpatients who met the Diagnostic and Statistical Manual of Mental Disorders, Revised Fourth Edition, criteria for anorexia nervosa, bulimia nervosa, and EDs not otherwise specified were rated with the Hamilton Depression Rating Scale (HDRS-17). A factor analysis of the HDRS-17 was carried out with the Cf-varimax rotation.

Results: Factor analysis showed 2 independent and clinically interpretable factors corresponding to "anxious depression" and "somatic complaints" that constituted the core of depression. For the HDRS-17, item response theory analyses revealed that most of the items were maximally related to the core concept of depression and provided a good functioning. The 17 items were distributed in almost the same way as in the factor analyses found by other authors with different clinical groups. We conclude therefore that for the sample of EDs, 2 factors constitute the core symptoms of depression and most of the items provided a good functioning.