Michael L. Free

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 I...

Biological and psychological processes in the treatment and maintenance of depression

While the efficacy of biological and psychological treatments of depression is now well established, the relationship between biological and psychological processes in the maintenance and treatment of depression is still unclear. This paper critically examines the evidence for and against the pharmacological and cognitive models of depression. Evidence is reviewed from statistical studies, studies attempting to find biological markers for depression, studies comparing various sets of criteria for endogenous depression, and treatment studies comparing the effectiveness of psychological and biological treatments of depression. It is concluded that the evidence for two discontinuous groupings (biological/endogenous, and psychological/reactive) is scanty. Psychological or biological models cannot by themselves account for recent findings, and therefore an interactional approach to depression is advocated. Three models, a separate processes model, a linear processes model, and a circular process model, are put forward as possible explanations for the interaction of psychological and biological processes in depression, and evidence for each is considered. It is concluded that although there is now sufficient evidence to support an interactive model of some kind in depression, there is still insufficient evidence to support the circular over the linear process model. Suggestions are made for future research.

Treatment Outcome of a Group Cognitive Therapy Program for Depression

A 12-session group program of cognitive therapy, designed by the first author, was evaluated with 35 persons suffering from major or minor depressive disorders. Effect-size scores were generated using the method of Nietzel, Russel, Hemmings, and Gretter (1987) and compared with cut-off points calculated using the method of Jacobson and Revenstorf (1988) and the norms established by Nietzel et al. (1987) in their meta-analysis. The effects of the Group Cognitive Therapy Program were found to be clinically significant according to the criteria of Jacobson and colleagues (Jacobson and Revenstorf, 1988; Jacobson, Follette and Revenstorf, 1984) for 73% of patients. It is concluded that the Group Cognitive Therapy Program is a clinically efficacious and cost-effective treatment for persons suffering from nonpsychotic, primary, unipolar depression.

Biological and psychological processes in recovery from depression during cognitive therapy

This study investigated the relationship between biological and psychological processes in the recovery phase of depression during treatment with cognitive therapy. In particular, we tested the hypothesis that biological and psychological processes are independent; the hypothesis that they are related in a linear or sequential process; and the hypothesis that there is a circular relationship between them. 35 depressed patients completed a 12 week program of cognitive therapy. Changes in measures of negative thinking and amine dysfunction over the course of therapy were compared for those who improved and those who did not. There was a significant relationship between improvement in symptoms and change for ATQ scores, DAS scores, and epinephrine levels. There was significant change in metanephrine levels during therapy which was not related to improvement. The changes were not consistent across indices. Although the results did not provide definite support for any of the four models of the relationship between biological and psychological variables during recovery from depression, the finding that there was some change in some of the indices of amine dysfunction during cognitive therapy indicates that the interface between biological and psychological processes in depression should continue to be studied.