Table 1.
Summary of reviews and meta-analysis in adult psychotherapy
| Author | Topic | Main findings |
|---|---|---|
| Specific mediators for specific diagnoses in specific therapies | ||
| Spinhoven et al. [15] | Changes in repetitive negative thinking for the treatment of depression in CBT (Meta-Analysis) | 36 RCTs but direction of the effect and causality remained unclear |
| Smits et al. [16] | Changes in threat reappraisal for the treatment of anxiety disorders in CBT (Meta-Analysis) | 25 RCTs with inconclusive results regarding treatment differences, suggesting that the mechanism is not specific to CBT, causality not established |
| Breuninger et al. [17] | Changes in cognitions in CBT for anxiety disorders (Review) | Of 30 RCTs, 17 studies supported the change theory, however changes in positive cognitions such as self-efficacy had stronger effects, contradicting or expanding CBT change theories |
| Fentz et al. [18] | Changes in panic self-efficacy and catastrophic beliefs in CBT for panic disorder (Review) | Of 33 original studies, only three carried out statistical mediation and only one yielded statistically significant results and the effects were not specific for CBT |
| Perestelo-Perez et al. [19] | Changes in rumination in depression using mindfulness-based therapies (Review) | Five out of 11 studies investigated the mediating effect of increased mindfulness/ acceptance and yielded inconclusive results |
| Several mediators for specific diagnoses in specific therapies | ||
| Magill et al. [20] | Change mechanisms in CBT in alcohol and drug abuse disorders (Meta-Analysis) | Coping and self-efficacy were the strongest mediators in ten studies, but it remained unclear if they were related to a CBT-specific change process |
| Radu et al. [22] | Changes in CBT for irritable bowel syndrome (Meta-Analysis) | Six studies with cognitive, emotional and behavioral mediators, with cognitive explaining the smallest amount of variance |
| Parsons et al. [21] | Internet-based CBT (CBT-I) on sleep-related problems (Meta-Analysis) | 11 RCTs found some evidence for cognitive mediators and no evidence for behavioral mediators |
| Therapy-specific mediators | ||
| Gu et al. [23] | Change mechanisms for mindfulness-based therapies (Meta-Analysis) | Changes in mindfulness (from 12 RCTs) and repetitive negative thinking (from six RCTs), but findings derived from a secondary analysis and not from the original studies. Inconclusive results for the effect of changes in self-compassion and psychological flexibility |
| Romano and Peters [24] | Change mechanisms in Motivational Interviewing (Meta-Analysis) | 19 studies showed no effect on patients’ motivation; significant mediation effects emerged in six studies with regard to in-session engagement (mainly measured as working alliance) |
| Stockton et al. [25] | Six change mechanisms in Acceptance and Commitment Therapy (Review) | Only six of the 12 included studies used formal mediation analysis and showed robust evidence only for acceptance |
| Diagnosis-specific mediators | ||
| Domhardt et al. [26] | Internet-based Interventions for depression (Review) | 64 different mediators, mainly CBT trials and cognitive mediators, considerably less studied mediator groups were behavioral and emotional mediators |
| Steubl et al. [27] | Internet-based Interventions for the treatment of PTSD (Review) | Three trials with four different and significant mediators: self-efficacy beliefs, perceived physical impairment, social acknowledgement, and disclosure of trauma |
| Isolated mediators | ||
| Baier et al. [34] | Therapeutic alliance as a putative mechanism of change (transdiagnostic) (Review) | 37 RCTs, of which about half were CBT, the majority of the studies (70%) found evidence for a mediating role of alliance on outcome. However, there was heterogeneity in the quality of studies and only seven were considered high quality |
| Jennissen et al. [35] | Insight as a curative transtheoretical factor (Review) | 22 studies (majority psychodynamic therapy), concluding that insight could be a relevant mechanism of change across different therapeutic schools |