Is Depression Taxonic, Dimensional, or Both?

The current investigation examines the potential importance of item selection in the ongoing discussion regarding the taxonicity of depression. Following J. C. Coyne (1994), we contrast the taxonicity of "distress" with the taxonicity of a syndrome more focused on somatic symptoms (i.e., the involuntary defeat syndrome). Using 4 samples of 984 undergraduates, we first replicate the J. Ruscio and A. M. Ruscio (2000) results by showing that distress item indicators are dimensional. We then demonstrate taxonicity using items focused on somatic symptoms and reflective of disruption of multiple homeostatic mechanisms. Results suggest that item selection is central to the determination of taxonicity in depression.