Self-reported depressive symptom measures: Sensitivity to detecting change in a randomized, controlled trial of chronically depressed, nonpsychotic outpatients

This study evaluated and compared the performance of three self-report measures: (1) 30-item Inventory of Depressive Symptomatology-Self-Report (IDS-SR₃₀); (2) 16-item Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR₁₆); and (3) Patient Global Impression-Improvement (PGI-1) in assessing clinical outcomes in depressed patients during a 12-week, acute phase, randomized, controlled trial comparing nefazodone, cognitive-behavioral analysis system of psychotherapy (CBASP), and the combination in the treatment of chronic depression. The IDS-SR₃₀, QIDS-SR₁₆, PGI-1, and the 24-item Hamilton Depression Rating Scale (HDRS₂₄) ratings were collected at baseline and at weeks 1-4, 6, 8, 10, and 12. Response was defined a priori as a ≥50% reduction in baseline total score for the IDS-SR₃₀ or for the QIDS-SR₁₆ or as a PGI-1 score of 1 or 2 at exit. Overall response rates (LOCF) to nefazodone were 41% (IDS-SR₃₀), 45% (QIDS-SR₁₆), 53% (PCI-1), and 47% (HDRS₁₇). For CBASP, response rates were 41% (IDS-SR₃₀), 45% (QIDS-SR₁₆), 48% (PGI-1), and 46% (HDRS₁₇). For the combination, response rates were 68% (IDS-SR₃₀ and QIDS-SR ₁₆), 73% (PGI-1), and 76% (HDRS₁₇). Similarly, remission rates were comparable for nefazodone (IDS-SR₃₀ = 32%, QIDS-SR ₁₆ = 28%, PGI-1 = 22%, HDRS₁₇ = 30%), for CBASP (IDS-SR₃₀ = 32%, QIDS-SR₁₆ = 30%, PGI-1 = 21%, HDRS ₁₇ = 32%), and for the combination (IDS-SR₃₀ = 52%, QIDS-SR₁₆ = 50%, PGI-1 = 25%, HDRS₁₇ = 49%). Both the IDS-SR₃₀ and QIDS-SR₁₆ closely mirrored and confirmed findings based on the HDRS₂₄. These findings raise the possibility that these two self-reports could provide cost- and time-efficient substitutes for clinician ratings in treatment trials of outpatients with nonpsychotic MDD without cognitive impairment. Global patient ratings such as the PGI-1, as opposed to specific item-based ratings, provide less valid findings.