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 …

Beck's theory of depression is arguably the most influential model ever developed on the
causes, course, and treatment of depression. Significant elements of the theory were
originally proposed in 1963, with a more comprehensive framework appearing in Beck's
seminal 1967 book. Since the 1967 volume, substantial elaboration of the model has been
suggested by Beck, as well as other theorists (Ingram, Miranda, & Segal, 1998). In its
contemporary form, the theory encompasses both descriptive elements of depression, as …