Den Boer, P. C. A. M, Wiersma, D., Ten Vaarwerk, I., Span, M. M., Stant, A. D., & Van Den Bosch, R. J. (2007). Cognitive self-therapy for chronic depression and anxiety: A multi-centre randomized controlled study. Psychological Medicine, 37, 329-339.

Correspondence Address:
Peter C. A. M. Den Boer, Department of Psychiatry, University Medical Center, P.O. Box 30.001, Groningen, Netherlands, 9700 RB, p.c.a.m.den.boer@psy.umcg.nl.

Abstract
Background: Non-professional treatment programmes are presumed to relieve the extensive need for care of anxiety and depression disorders. This study investigates the effectiveness of cognitive self- therapy (CST) in the treatment of depression or generalized anxiety disorder. Method: Patients (n=151) were randomized to receive CST or treatment as usual (TAU) in a trial lasting for 18 months, measuring symptoms (SCL-90; main outcome), social functions, quality of life and utilization of care. Results: Patients in both conditions improved significantly, but no difference was found between the conditions. Reduction of symptoms, improvement of social functions and medical utilization were maintained at the end of the 18 months. Medical care utilization (therapist contact and hospitalization) was lower for CST than for TAU. No suicides occurred. Conclusions: Cognitive self-therapy is likely to decrease the need for care of chronic depression and anxiety disorders, but it has not been proven to be more effective than treatment as usual. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

Haby, M. M., Donnelly, M., Corry, J., & Vos, T. (2006). Cognitive behavioural therapy for depression, panic disorder and generalized anxiety disorder: A meta-regression of factors that may predict outcome. Australian and New Zealand Journal of Psychiatry, 40, 9-19.

Correspondence Address:
Michelle M. Haby, Health Surveillance and Evaluation Section, Public Health Group, Department of Human Services, Level 18, 120 Spencer Street, Melbourne, VIC, Australia, 3000, michelle.haby@dhs.vic.gov.au.

Abstract
Objective: Objective: To determine which factors impact on the efficacy of cognitive behavioural therapy (CBT) for depression and anxiety. Factors considered include those related to clinical practice: disorder, treatment type, duration and intensity of treatment, mode of therapy, type and training of therapist and severity of patients. Factors related to the conduct of the trial were also considered, including: year of study, country of study, type of control group, language, number of patients and percentage of dropouts from the trial. Method: We used the technique of meta-analysis to determine an overall effect size (standardized mean difference calculated using Hedges' g) and meta-regression to determine the factors that impact on this effect size. We included randomized controlled trials with a wait list, pill placebo or attention/psychological placebo control group. Study participants had to be 18 years or older and all have diagnosed depression, panic disorder (with or without agoraphobia) or generalized anxiety disorder (GAD). Outcomes of interest included symptom, functioning and health-related quality of life measures, reported as continuous variables at post-treatment. Results: Cognitive behavioural therapy for depression, panic disorder and GAD had an effect size of 0.68 (95% 01 = 0.51-0.84, n = 33 studies, 52 comparisons). The heterogeneity in the effect sizes was fully explained by treatment, duration of therapy, inclusion of severe patients in the trial, year of study, country of study, control group, language and number of dropouts from the control group. Disorder was not a significant predictor of the effect size. Conclusions: Cognitive behavioural therapy is significantly less effective for severe patients and trials that compared CBT to a wait-list control group found significantly larger effect sizes than those comparing CBT to an attention placebo, but not to a pill placebo. Further research is needed to determine whether CBT is effective when provided by others than psychologists and whether it is effective for non-English-speaking patient groups. (PsycINFO Database Record (c) 2006 APA, all rights reserved)

Siev, J., & Chambless, D. L. (2007). Specificity of treatment effects: Cognitive therapy and relaxation for generalized anxiety and panic disorders. Journal of Consulting and Clinical Psychology, 75, 513-522.

Correspondence Address:
Jedidiah Siev, Department of Psychology, University of Pennsylvania, 3720 Walnut Street, Philadelphia, PA, USA, 19104-6241, jsiev@psych.upenn.edu.

Abstract
The aim of this study was to address claims that among bona fide treatments no one is more efficacious than another by comparing the relative efficacy of cognitive therapy (CT) and relaxation therapy (RT) in the treatment of generalized anxiety disorder (GAD) and panic disorder without agoraphobia (PD). Two fixed-effects meta-analyses were conducted, for GAD and PD separately, to review the treatment outcome literature directly comparing CT with RT in the treatment of those disorders. For GAD, CT and RT were equivalent. For PD, CT, which included interoceptive exposure, outperformed RT on all panic-related measures, as well as on indices of clinically significant change. There is ample evidence that both CT and RT qualify as bona fide treatments for GAD and PD, for which they are efficacious and intended to be so. Therefore, the finding that CT and RT do not differ in the treatment of GAD, but do for PD, is evidence for the specificity of treatment to disorder, even for 2 treatments within a CBT class, and 2 disorders within an anxiety class. (PsycINFO Database Record (c) 2007 APA, all rights reserved) (journal abstract)