Journal of Psychopathology and Behavioral Assessment, Vol. 26, No. 4, December 2004 ( C  2004) Structural Validation of the Hamilton Depression Rating Scale Jason C. Cole, 1,6 Sarosh J. Motivala, 1 Jeff Dang, 1 Anne Lucko, 2 Nancy Lang, 3 Myron J. Levin, 3 Michael N. Oxman, 4,5 and Michael R. Irwin 1 Accepted March 8, 2004 Despite the prolific use of the Hamilton Depression Rating Scale (HDRS), there have been no prior studies using confirmatory factor analysis (CFA) to compare competing HDRS latent structures. The current study undertakes this task, examining CFAs on 397 older adults on the most stable latent models previously posited and a new rationally derived model by Cole and Motivala. CFAs were evaluated in their original first-order structure and in hierarchically related counterparts. All hierarchical models performed significantly better than their first-order counterparts. Moreover, the hierarchical Cole and Motivala model was significantly better on all comparative criteria than any of the other models. However, none of the tested models obtained sufficient fit with the data suggesting psychometric, scoring, or content limitations of the scale. KEY WORDS: depression; latent analysis; confirmatory factor analysis; Hamilton Depression Rating Scale. In 1960, Max Hamilton published an article detail- ing his initial development of the Hamilton Depression Rating Scale (HDRS; Hamilton, 1960). Since then, the HDRS has become acknowledged as the most frequently used observer-based measure for research regarding the treatment of depression (Grundy, Lunnen, Lambert, Ashton, & Tovey, 1994; Williams, 1988). As such, several psychometric investigations of the HDRS have been undertaken, and the scale generally is considered to have satisfactory reliability and validity (Moran & Lambert, 1983). Structural validity (i.e., the accuracy and consistency of findings regarding a measure’s factor structure) of the HDRS is, nevertheless, more tenuous. Proper structural validation of the HDRS has been hindered by two scale-specific issues: there is often 1 Cousins Center for Psychoneuroimmunology, University of California, Los Angeles, California. 2 San Diego Veterans’ Medical Research Foundation. 3 Health Sciences Center, University of Colorado, Denver, Colorado. 4 University of California, San Diego, California. 5 San Diego Veterans Affairs Healthcare System, San Diego, California. 6 To whom correspondence should be addressed at Cousins Center for Psychoneuroimmunology, UCLA Neuropsychiatric Institute, 300 UCLA Medical Plaza, Room 3148, Los Angeles, California 90095- 7076; e-mail: jccole@mednet.ucla.edu. confusion about which scale is the true HDRS, and different scoring procedures have been used for HDRS items. Grundy et al. (1994) conducted a review of various articles using the HDRS, including details of 10 different versions, along with many derivative measures and scales. After a review of 688 articles that used the HDRS, Grundy et al. found that 42% of these studies incorrectly referenced the specific HDRS version used. Most HDRS factor analyses have been conducted on the 17-item version (see Hamilton, 1967), but there are exceptions (see Hamdi, Amin, & Abou-Saleh, 1997). Another problem with scale clarity exists. Hamilton’s (1960) article lists “loss of weight” as item 16 and “insight” as item 17, yet his 1967 article reverses the order of these items. Consequently, some structural analyses of the HDRS have listed the HDRS items following Hamilton’s 1960 layout (e.g., Fleck, Poirier-Littre, Guelfi, Bourdel, & Loo, 1995; O’Brien & Glaudin, 1988; Riskind, Beck, Brown, & Steer, 1987), while others have followed Hamilton’s 1967 layout (e.g., Addington, Addington, & Atkinson, 1996; Gibbons, Clark, & Kupfer, 1993; Marcos & Salamero, 1990; Mowbray, 1972; Ramos-Brieva & Cordero-Villafafila, 1988). The 17-item HDRS employs different scoring pro- cedures with nine items scored on a 5-point scale (0–4) 241 0882-2689/04/1200-0241/0 C  2004 Springer Science+Business Media, Inc.