Cognitive processes in cognitive therapy: Evaluation of the mechanisms of change in the treatment of depression

A central theoretical principle guiding cognitive therapy is that mediation by cognitive processes is linked to the successful treatment of depression. The most recent review of the literature on this question is over a decade old and was suggestive of cognitive mediation for cognitive therapy, but was not conclusive. Since this review, a number of studies have been published that address cognitive mediation. The mediation hypothesis can be broadly defined as encompassing two related questions: cognitive mediation framed as "are cognitive changes associated with therapeutic improvement," and cognitive specificity from the perspective of "are changes in cognition specific to cognitive therapy?" This latter question is particularly important when cognitive therapy is compared to pharmacotherapy. This article reviews the current literature associated with these questions. Our review indicates that the current body of research generally supports cognitive mediation, but is considerably more mixed for cognitive specificity. However, some evidence suggests that cognitive changes associated with pharmacotherapy are more superficial than those associated with cognitive therapy.