Estimates of the prevalence of depression following TBI vary
considerably – ranging from 6% to 77% (Rutherford et al., 1977;
Varney et al., 1987). This variability not only seriously limits the
clinical utility of these findings, but also raises questions about
its source. Differences in how depression is conceptualised (diagnosed
disorder vs self-reported symptoms), the diagnostic criteria
and/or measures that are used to assess depression and a number of
patient characteristics (e.g., injury severity), may explain a signifi-
cant amount ofthis variance; however, we do not currently know to
what extent these variables impact on estimates of the prevalence
of depression following TBI.