Do Cognitive Behaviour Therapies Validate Cognitive Models of Mood Disorders? A Review of the Empirical Evidence

Abstract
The efficacy of Cognitive Behaviour Therapy (CBT) in the treatment of depression is now established. However, explanations for the efficacy of CBT are mixed. The evidence needed to support the explanation advanced by cognitive theory is lacking. This paper critically reviews the available empirical evidence. Forty‐four outcome or process studies of therapy with depression are reviewed and 21 of these are subjected to a meta‐analysis to investigate the relationship between change in cognitions and change in level of depression during different kinds of therapy. Our analysis shows that: (1) change in cognitive style occurs in all four categories of treatment: CBT, Drug Therapy, Other‐Psychological Therapy, and Waiting List; (2) there was a significant difference between Waiting List and all the active treatments in change in cognitions, but not between active treatments; (3) the degree of change in cognitive style is significantly related to change in depression as measured by the Beck Depression Inventory (BDI), but not the Hamilton Rating Scale for Depression (HRS‐D); and (4) the relationship between cognitive change and depression is not unique to CBT. Our findings show that CBT does provide some support for the cognitive models of depression but the relationship between cognitive change and recovery from depression is not unique to CBT.