Objective: Fatigue is a complex, multidimensional condition. Although it is often associated with
depression, it is not known whether it has a distinct network from depression or whether it can be
clinically evaluated, separately. This study describes preliminary findings in the development of a brief,
clinician-administered instrument to measure fatigue in the context of depressive disorders using items
from existing clinician-administered depression and mania scales.
Methods: Based on items from prior fatigue measurements, items were selected from the Hamilton
Depression Rating Scale (HDRS), MontgomeryeAsberg Depression Rating Scale (MADRS), Young Mania
Rating Scale, and Structured Interview Guide for HDRS with Atypical Depression. The final items
composed the NIH-Brief Fatigue Inventory (NIH-BFI). Responses from 89 depressed adults collected preand
post-antidepressant therapy (ADT) determined the reliability and consistency of the NIH-BFI using
Cronbach's alpha and principal components analysis (PCA). Correlations of the NIH-BFI and fatigue items
from other scales before and after ADT explored validity.
Results: The 7-item NIH-BFI had Cronbach alphas ranging from 0.81 to 0.88 and PCA indicating a single
dimension. The NIH-BFI score was strongly correlated (r ¼ 0.73, p < 0.001) with fatigue items from Beck
Depression Index, with MADRS without fatigue items (r ¼ 0.77, p < 0.001), and HDRS without fatigue
items (pre: r ¼ 0.69, p < 0.001).
Conclusions: Preliminary findings show support for internal consistency reliability and validity of the
NIH-BFI, a clinician-administered measure of fatigue. Further testing in other clinical populations is
recommended to obtain additional information on reliability and validity. The NIH-BFI provides a
method for clinician-rated fatigue that may be a separate from depression.