Medline ® Abstract for Reference 32

OBJECTIVE: This study evaluated the concordance between the self-report and the clinician-rated versions of the Inventory of Depressive Symptomatology (IDS-30) and between the two versions of the briefer 16-item Quick Inventory of Depressive Symptomatology (QIDS-16).

METHODS: Data were gathered for 544 adult outpatients with psychotic (N = 106) or nonpsychotic (N = 438) major depressive disorder at 14 public sector mental health clinics in the Texas Medication Algorithm Project. Data for the QIDS-16 were extracted from the IDS-30. Baseline scores and scores from the final study visit at or before month 12 were analyzed. The clinician-rated and the self-report versions of each scale were compared in their identification of response to treatment and remission.

RESULTS: The average baseline IDS-SR-30 total score was 2.2 points higher (indicating greater severity) than the IDS-C-30 score; the average QIDS-SR-16 total score was only .3 points higher than the QIDS-C-16 score. The IDS-SR-30 and the IDS-C-30, as well as the QIDS-C-16 and QIDS-SR-16, agreed substantially in classifying response and remission for patients, regardless of whether the patients had psychotic features. None of a large number of clinical and demographic features accounted for differences between the QIDS-SR-16 and QIDS-C-16 total scores.

CONCLUSIONS: Either the IDS-30 or the QIDS-16 self-report adequately assesses depressive symptom severity among public-sector outpatients with major depressive disorder. The briefer QIDS-16 may be preferred to save time and cost.