sessions was negatively associated with effect size. Conclusions: The findings demonstrate the utility of CBT across a large and diverse sample of studies and under rigorous conditions for establishing efficacy. CBT effects were strongest with marijuana users, when CBT was compared with no treatment, and may be larger with women than with men and when delivered in a brief format.
Hofmann, S. G., Sawyer, A. T., Korte, K. J. & Smits, J. A. (2009). International Journal of Cognitive Therapy, 2(2), Special issue: Metacognition. 160-175.
In order to examine the benefit of adding pharmacotherapy to cognitive-behavioral therapy (CBT) for anxiety disorders, we searched for studies comparing CBT plus pharmacotherapy and CBT plus pill placebo for adults meeting DSM-III-R or DSM-IV diagnostic criteria for an anxiety disorder between the 1st available year and July 1, 2008. Of 874 studies that were initially considered, 11 studies were identified, representing 471 patients with posttreatment completer data and 236 participants with follow-up completer data. CBT plus pharmacotherapy was generally more effective than CBT plus placebo at posttreatment for measures of anxiety disorder severity (Hedges' g = 0.59, 95% confidence interval: 0.29-0.90) and treatment response (OR: 1.95,95% confidence interval: 1.25-3.03), but not at 6-month follow-up. Despite the relatively small number of studies, the fail-safe N suggested that the results are reliable. The largest effect sizes at posttreatment were found for panic disorder and generalized anxiety disorder. No differences were observed between self-report and clinician-administered measures. The reported effect sizes linearly decreased with publication year. In sum, there is preliminary evidence to suggest that adding pharmacotherapy to CBT is a useful short-term treatment strategy at least for some of die anxiety disorders.
Venning, A., Kettler, L., Eliott, J. & Wilson, A. (2009). International Journal of Evidence-Based Healthcare, 7(1), 15-33.
Background: The onset of depression during adolescence can adversely impact future functioning. Cognitive–Behavioural Therapy (CBT) has been suggested to prevent depression in adolescence by providing an individual with the ability to interpret and the tools to deal with the impact of negative life events. Objective: Examine the best available evidence to determine the effectiveness of CBT to prevent the onset of depression in young people, and assess whether the incorporation of hopeful elements makes CBT more effective. Search strategy: A comprehensive three-step search strategy was developed to find both published and unpublished studies in English from 1987 to March 2007. Papers selected for retrieval were then assessed for methodological validity by two independent reviewers. Selection criteria: Papers that used a randomised controlled design and investigated the efficacy of CBT to prevent the onset of depression in young people between the age of 10 years and 16 years were included. Papers were included if the CBT involved between four and 15 sessions, a follow-up period of between 3 and 24 months and included typical strategies, such as the identification of negative and irrational beliefs, the establishment of links between thoughts, feelings and behaviours, and provided tools so participants could self-monitor these. Data analysis: Data were extracted using the standard tool from the Joanna Briggs Institute, pooled in a meta-analysis, and then grouped and analysed according to the amount of hopeful elements the CBT was judged to contain. Results and conclusion: Limited evidence was found to indicate that CBT, regardless of its content (i.e. with or without hopeful elements), is effective at preventing the onset of clinical levels of