Meta-analyses of MMBI
Hundreds of studies have been conducted about the effectiveness of MMBI and there are numerous meta-analyses that offer an overview of treatment effects. Goyal and colleagues (2014) examined the effects ofstructured MMBI, including mindfulness, mantra, and other meditation programs, in 47 randomized controlled trials (RCTs) with active control conditions involving 3515 participants. This meta-analysis of MMBI for psychological stress and well-being concluded that mindfulness programs had small pre/post effects on depression, anxiety, and pain, but no effects relative to active control groups. The mantra programs did not improve any of the outcomes, but there was insufficient evidence to evaluate them, owing to the small number of trials that were included and the fact that some mantra studies included patients with very low symptom levels at pretreatment (Goyal et al. 2014).
Some meta-analyses have examined effects of mindfulness programs specifically. A recent meta-analysis of 209 psychological and medical outcome studies of mindfulness-based therapy (MBT) conducted with a total of 12,145 participants found that MBT was associated with improvements in depression and anxiety. MBT was moderately effective in pre/post studies, was more effective than supportive therapies, but was not significantly more effective than relaxation, psychoeducation, traditional CBT, or behavior therapy at follow-up. However, mindfulness was associated with positive clinical outcomes across the 45% of studies that included a mindfulness measure, suggesting that mindfulness has some role in MBT effects (Khoury et al. 2013).
The effects of MBT for current diagnoses of depression or anxiety were addressed in a meta-analysis of12 RCTs involving 578 participants. MBTs were moderately more effective than control conditions for primary symptom severity related to depressive, but not anxiety, disorders. Like the Khoury et al. (2013) and Goyal et al. (2014) meta-analyses, MBTs weren’t significantly more effective than active control conditions. In addition, MBCT, but not MBSR, showed significant effects on primary symptom severity (Strauss et al. 2014). Both the Khoury et al. (2013) and Strauss et al. (2014) studies found similar average attrition rates (approximately 15-16%), which were similar to those observed in CBT studies (Strauss et al. 2014).
The effects of KBM were addressed in a meta-analysis of 22 studies involving 1747 participants, of which only three studies recruited patients and seven included an active control condition. In comparison to inactive control conditions, KBM was moderately effective in decreasing depression, and in increasing mindfulness, compassion, and self-compassion, but results against active controls were inconclusive. The authors noted that KBM may be challenging for some, at least at the beginning stages of practice (Galante et al. 2014).
Overall, meta-analyses indicate that MMBIs produce pre/post changes in mindfulness, some psychological symptoms, and other indicators of wellbeing, but evidence for comparative effects among currently diagnosed patients is sparse, indicating that the MM component of studies does not seem to add to treatment effects beyond what is gained from participation in other active treatments, such as CBT, behavior therapy, or psychoeducation. The lack of superiority is not evidence for the equivalence or non-inferiority of MMBI relative to active control conditions; such conclusions require results from specifically designed and well powered clinical trials (Goyal et al. 2014; Greene et al. 2008). Research addressing the effects of specific MMBI treatment components would allow interventions to be more closely tailored to specific psychotherapeutic applications and could perhaps lead to more successful interventions.