In addition to functionality, on the other hand, it seems to be also insufficient that even long term effect iveness has not been meta analysed at all. Considering methodological aspects, it seems that past meta analyses have crucial selleck chemicals llc limitations in quality. The first issue is the heterogeneity of both targeted disorders and intervention. In the former, three meta analytic studies dealt with depression and other disor ders as common target dis orders, implying a critical bias in the results due to considerable diagnostic heterogeneity, as CBT for depression and that for other Inhibitors,Modulators,Libraries disorders, such as anxiety disorders, are theoretically different interventions. In deed, in these three, the effect sizes of CCBT for anxiety were generally greater than CCBT for depression.

In contrast, two other meta analyses exclu sively dealt with depression. Nevertheless, there still Inhibitors,Modulators,Libraries remain the heterogeneous problems of intervention. Gellatly et al. included not only ten CCBT research stud ies but also twenty nine studies with non CCBT inter ventions, such as bibliotherapy, indicating that the results of this meta analysis cannot be accepted as those of solely CCBT intervention. Compared to this review, Andrews et al. used the largest number to date of RCTs on depression Inhibitors,Modulators,Libraries only CCBT. Even so, this meta analysis included two inappropriate studies, as mentioned below under Results. Secondly, the published systematic reviews have not paid due attention to the problem of dropouts. Some studies suggest that CCBT has higher attrition rates than other therapies.

However, one meta analysis by Waller and Gilbody indicated that there was no significant difference between CCBT users and controls, but this meta analysis had substantial diagnostic Inhibitors,Modulators,Libraries heterogeneity. Since uneven attrition Inhibitors,Modulators,Libraries between or among intervention arms can be a significant cause of bias, more rigorous consideration needs to be given to this factor. Thirdly, the published meta analyses have not exam ined publication bias in the available literature on CCBT. Lastly, there have been an increasing number of new studies published since the selleck most recent systematic review. Therefore, we conducted a meta analysis of clinical effectiveness of single CCBT for adult depression, taking the above methodological factors into consideration with an additional evaluation of functional outcomes and long term follow up effects. Methods Identification and selection of studies All RCTs completed and analysed by 11 July, 2011 were eli gible for inclusion in this review. Five bibliographic data bases were used. We also searched tiple search terms were used and modified for each database, as necessary. The search was performed on 11 July, 2011.