Beating a dead dodo bird: Looking at signal vs. noise in cognitive‐behavioral therapy for anxiety disorders.

The present qualitative and quantitative review examines the efficacy of CBT versus non-CBT treatments for anxiety disorders and suggests that a prior failure (Baardseth et al., 2013, p. 395) to detect differences in outcome can easily be attributed to excessive error variance in the analysis, essentially burying the “signal” under “noise.” Several sources of error variance are identified, including type of comparison therapy, diagnosis, what outcome is being measured, and study quality. It is suggested that the “signal” of CBT versus other psychotherapies can easily be seen or not seen, depending on what one chooses to analyze. Recommendations are made for further study about the relative efficacy of different psychological treatments.