title: A critical examination of the sensitivity of unidimensional subscales derived from the Hamilton Depression Rating Scale to antidepressant drug effects.
abstract: Unidimensional subscales for assessment of major depression may be more sensitive to antidepressant drug effects than the Hamilton Depression Rating Scale (HAM-D). To further examine this possibility, we analyzed pooled data from eight comparable, well-controlled clinical trials of venlafaxine and compared such subscales and the 17-item HAM-D (HAM-D(17)) based on effect size and number of patients required for 80% power. Symptoms of depression were assessed using the HAM-D among intent-to-treat patients (2045) randomly assigned to receive venlafaxine (immediate release, n = 474; extended release, n = 377), one of several selective serotonin reuptake inhibitors (SSRIs) (n = 748), or placebo (n = 446) for up to 8 weeks. With SSRIs or venlafaxine vs. placebo, subscales yielded effect sizes (0.328-0.528) 16 to 76% larger than the HAM-D(17) did (0.237 and 0.396, respectively), and required 31 to 64% fewer patients for 80% power. With venlafaxine vs. SSRIs, the subscales showed no advantage over the HAM-D(17); all devices yielded comparable, positive effect sizes (0.183-0.195). Final subscale scores significantly predicted (all P < 0.05) whether patients met criteria for remission (eg, HAM-D(17) score of < or = 7). These findings suggest that unidimensional subscales are more sensitive to antidepressant drug effects than the HAM-D(17) is, but only in active agent/placebo comparisons. Our data further suggest the subscales can predict the presence of remission. Given these findings, prudent use of these subscales may be appropriate, cost-effective, and informative.
authors.affiliation: Clinical Biostatistics, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426, USA. entsuaa@wyeth.com
authors.forename: Richard
authors.initials: R
authors.lastname: Entsuah
authors.forename: Michelle
authors.initials: M
authors.lastname: Shaffer
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000627:therapeutic use*; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000188:drug therapy*; D004311:Double-Blind Method; D006801:Humans; D008875:Middle Aged; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires
chemical_list: D000928:Antidepressive Agents