First, it can give other researcher access to the studies we have collected and facilitate replications and independent analyses of selections of studies. In this paper, we will present the methods we have used to build this database, and we will provide an overview of the characteristics of the studies that have been included in the database.
Using this database, we have published a series of meta-analyses on subgroups of this dataset, and several other meta-analyses are currently being prepared. In the past few years, our group has worked on a database of all randomized studies of psychological treatments for depression, which is updated every year. Based on a systematic review of meta-analyses in the field and a count of the studies included in these meta-analyses, we estimated that at least 160 controlled and comparative studies have examined the effects of psychological treatments of depression. Only a few meta-analyses have tried to examine all relevant studies on psychological treatments for depression. This has been done in order to examine the effects of one type of intervention or one target population. Most meta-analyses in this field have focused on one specific subgroup of studies. The effects of psychological treatments are comparable to the effects of pharmacological treatments, while the combination is somewhat more effective than treatment with pharmacotherapy alone or psychotherapy alone. Interestingly, both individual and group treatments are effective in the treatment of depression, as are guided self-help and psychoeducational treatments of depression. Cognitive behavior therapy is the treatment format that has been examined in most studies, although it is not yet clear whether it is more effective than other types of treatments. Psychological treatments are not only effective in adults, but also in older adults, in women with postpartum depression, and in patients with both depression and general medical disorders. These studies have shown clearly that psychological treatments have large effects, in terms of symptom reductions and increased well-being. In recent decades, a large number of trials have been conducted in which the effects of psychological treatments of depression have been examined. The database we have presented in this paper can help to integrate the results of these studies in future meta-analyses and systematic reviews on psychological treatments for depression. The number of studies examining the effects of psychological treatments of depression has increased considerably in the past decades, and this will continue in the future. The data on the 149 included studies are presented in order to give other researchers access to the studies we collected, and to give background information about the meta-analyses we have published using this dataset. In the database, we present selected characteristics of each study, including characteristics of the patients (the study population, recruitment method, definition of depression) characteristics of the experimental conditions and interventions (the experimental conditions, N per condition, format, number of sessions) and study characteristics (measurement times, measures used, attrition, type of analysis and country).
In the 149 included studies, a total of 11,369 patients participated.
The 149 studies included in these 9 meta-analyses are included in the current database. We conducted nine meta-analyses of subgroups of studies taken from this dataset.
We included randomized studies in which the effects of a psychological therapy on adults with depression were compared to a control condition, another psychological intervention, or a combined treatment (psychological plus pharmacological). We conducted a comprehensive literature search of the major bibliographical databases (Pubmed Psycinfo Embase Cochrane Central Register of Controlled Trials) and we examined the references of 22 earlier meta-analyses of psychological treatment of depression. The database can be accessed freely through the Internet. In this paper, we present a database of controlled and comparative outcome studies on psychological treatments of depression, based on a series of meta-analyses published by our group.
The number of studies in this area is increasing rapidly. A large number of randomized controlled studies have clearly demonstrated that psychological interventions are effective in the treatment of depression.