Elucidating the Cognitive Mechanisms Underpinning Behavioural Activation.

Depression represents a pervasive and devastating psychological difficulty. It affects over 21% of the population at some point in their lives and can have an unimaginable impact on both individuals and society. Behavioural activation represents a popular intervention for depression and is commonly used by psychologists internationally. Despite its popularity, the cognitive mechanisms underpinning the efficacy of behavioural activation remain elusive. This paper will review the literature on this intervention and propose an account of the cognitive mechanisms underlying its therapeutic efficacy. Specifically, it is argued that behavioural activation is effective because it increases both the density of outcomes in ones environment and the density of highly salient action-outcome contingencies, which may otherwise be absent due to reduced motivation. The clinical implications are subsequently discussed, with reference to future research.