Calibration of response and remission cut-points on the Beck Depression Inventory-Second Edition for monitoring seasonal affective disorder treatment outcomes

Abstract

Background: The purpose of this study is to define treatment response and remission cut-point scores for the Beck Depression Inventory-Second Edition (BDI-II) when used to monitor seasonal affective disorder (SAD) treatment.

Methods: Data from two published randomized clinical trials for SAD were utilized to complete a ROC analysis to define response and remission thresholds for the BDI-II. The Structured Interview Guide for the Hamilton Rating Scale for Depression-Seasonal Affective Disorder Version (SIGH-SAD) was used as a reference standard. Data from the two trials included BDI-II and SIGH-SAD scores for patients at baseline, 6 weeks (post-treatment), and 1 year (next winter).

Results: BDI-II score of ≤ 9 was the derived criterion for remission of SAD, and BDI-II score decrease of 50% from baseline was the criterion for treatment response.

Limitations: Study participants were primarily female (94%) and Caucasian (80%) so demographic diversity of the sample was limited.

Conclusion: This study validated BDI-II scores compared to the SIGH-SAD reference standard. The BDI-II has greater potential for widespread use by clinicians than the SIGH-SAD to monitor SAD patients because it is a brief self-report instrument that can be conveniently administered in the waiting room.

Conflict of interest statement

The authors have no conflict of interest to report.

Copyright © 2011 Elsevier B.V. All rights reserved.

Figures

Figure 1. BDI-II scores as a function of SIGH-SAD scores at baseline and 6 weeks

Legend: BDI, Beck Depression Inventory-II SIGH-SAD – Structured Interview guide for the Hamilton Rating Scale for Depression – Seasonal Affective Disorder Version

Figure 2. BDI-II scores at 6 weeks (percentage of baseline) as a function of SIGH-SAD scores at 6 weeks (percentage of baseline)

Treatment response is defined as 50% reduction in BDI-II Reference standard is 50% reduction in SIGH-SAD Additional lines indicate 50% baseline BDI-II and 50% baseline SIGH-SAD scores Correct classification (n=58); Incorrect classification (n=11)