Psychometric properties of the Quick Inventory of Depressive Symptomatology in adolescents

Abstract

Objective: The clinician-rated (QIDS-C₁₆) and self-report (QIDS-SR₁₆) versions of the 16-item Quick Inventory of Depressive Symptomatology have been extensively examined in adult populations. This study evaluated both versions of the QIDS and the 17-item Children's Depressive Rating Scale - Revised (CDRS-R) in an adolescent outpatient sample.

Method: Both the QIDS-C₁₆ and QIDS-SR₁₆ were completed for the adolescents. Three different methods were used to complete the QIDS-C₁₆: (a) adolescents' responses to clinician interviews; (b) parents' responses to clinician interview; and (c) a composite score using the most pathological response from the two interviews. Both classical and item response theory methods were used. Factor analyses evaluated the dimensionality of each scale.

Results: The sample included 140 adolescent outpatients. All versions of the QIDS, save the parent interview, and the CDRS-R were very reliable (α ≥ 0.8). All four versions of the QIDS are reasonably effective and unidimensional. The CDRS-R was clearly at least two-dimensional. The CDRS-R was the most discriminating among low and extremely high levels of depression. The QIDS-SR₁₆ was the most discriminating at moderate levels of depression. There was no relation between the QIDS scores and concurrent Axis III comorbidities.

Conclusion: The QIDS-C₁₆ and the QIDS-SR₁₆ are suitable for use in adolescents.

Copyright © 2010 John Wiley & Sons, Ltd.

Figures

Figure 1

Scree lots for the QIDS‐C16(Adol), QIDS‐C16(Par), QIDS‐C16(Comp) and QIDS‐SR16.

Figure 2

Scree plot for the CDRS‐R.

Figure 3

Test information functions (TIFs) for the QIDS‐C16(Adol), QIDS‐C16(Par), QIDS‐C16(Comp), QIDS‐SR16, and CDRS‐R.