Neural effects on patients with major depressive disorder: systematic review

Vignaud, P., et al. (2018). Neural effects of mindfulness-based interventions on patients with major depressive disorder: A systematic review. Neuroscience & Biobehavioral Reviews, vol. 88, pp. 98-105, https://doi.org/10.1016/j.neubiorev.2018.03.004.

Abstract. Growing evidence has suggested that mindfulness-based interventions (MBIs) could have beneficial effects on the acute phase of depression and on the prevention of depressive relapse or recurrence. Despite growing clinical interest, the effects of MBIs on brain functioning in patients with MDD remain unclear. The aim of this systematic review was to assess the changes in brain functioning associated with MBIs in patients with MDD.

A systematic search was conducted, and of the 56 articles found, 8 were eligible. MBIs have modulatory effects on several brain regions implicated in the pathophysiology of MDD, such as the prefrontal cortex, the basal ganglia, the anterior and posterior cingulate cortices, and the parietal cortex. These regions have been implicated in self-awareness, attention and emotion regulation.

Some of these findings were consistent with the effects of MBIs observed in healthy subjects and patients with other psychiatric disorders, especially enhanced activity in the frontal and subcortical regions related to the improved somatosensory awareness. Further studies are needed to elucidate the mechanisms of MBIs in MDD.

Interventions for psychiatric disorders

Goldberg, S. B., et al. (2018). Mindfulness-based interventions for psychiatric disorders: A systematic review and meta-analysis. Clinical psychology review, vol. 59, pp. 52-60, https://doi.org/10.1016/j.cpr.2017.10.011. Full text.

Highlights —

•  We examined the relative efficacy of mindfulness-based interventions on clinical symptoms of psychiatric disorders.

•  142 randomized clinical trials were included (N = 12,005 participants). Control conditions were coded on a five-tier system.

•  At post-treatment, mindfulness interventions were equivalent to evidence-based treatments and superior to other comparisons.

•  At follow-up, mindfulness interventions were equivalent to minimal and evidence-based treatments and superior to others.

•  The most consistent evidence for mindfulness-based interventions was seen for depression, pain, smoking, and addictions.

Effectiveness of meditation retreats: meta-analysis

Khoury, B., at al. (2017). Effectiveness of traditional meditation retreats: A systematic review and meta-analysis. Journal of psychosomatic research92, 16-25, https://doi.org/10.1016/j.jpsychores.2016.11.006. Taken from the Abstract.

Background. An increasing number of studies are investigating traditional retreats. Very little, however, is known about their effectiveness.

Objective. To evaluate the effectiveness of meditation retreats on improving in general population. A total of 20 papers (N = 2912) were included.

Results suggested large effects on measures of anxiety, depression, stress, and moderate effects on measures of emotional regulation and quality of life. As to potential mechanisms of actions, results showed large effects on measures of  mindfulness and compassion, and moderate effects on measures of acceptance. 

Meditation and PTSD

Hilton, L., et al. (2017). Meditation for posttraumatic stress: Systematic review and meta-analysis. Psychological Trauma: Theory, Research, Practice, and Policy9(4), 453. From the Abstract.

Objective: We conducted a systematic review and meta-analysis that synthesized evidence from randomized controlled trials of meditation interventions to provide estimates of their efficacy and safety in treating adults diagnosed with posttraumatic stress disorder (PTSD).

Results: In total, 10 trials on meditation interventions for PTSD with 643 participants met inclusion criteria. Across interventions, adjunctive meditation interventions of mindfulness-based stress reduction, yoga, and the mantram repetition program improve PTSD and depression symptoms compared with control groups, but the findings are based on low and moderate quality of evidence.

Effects were positive but not statistically significant for quality of life and anxiety, and no studies addressed functional status. The variety of meditation intervention types, the short follow-up times, and the quality of studies limited analyses.

Conclusions: Meditation appears to be effective for PTSD and depression symptoms, but in order to increase confidence in findings, more high-quality studies are needed on meditation as adjunctive treatment with PTSD-diagnosed participant samples large enough to detect statistical differences in outcomes.

Beneficial for asthma?

Paudyal, P., et al. (2018). Meditation for asthma: Systematic review and meta-analysis. Journal of Asthma55(7), 771-778, https://doi.org/10.1080/02770903.2017.1365887. 

From the AbstractOur review suggests that there is some evidence that meditation is beneficial in improving quality of life in asthma patients. As two out of four studies in our review were of poor quality, further trials with better methodological quality are needed to support or refute this finding.

Mindfulness-based therapy for dyspnea

Mularski, R. A., et al. (2009). Randomized controlled trial of mindfulness-based therapy for dyspnea in chronic obstructive lung disease. The Journal of Alternative and Complementary Medicine15(10), 1083-1090, DOI: 10.1089=acm.2009.0037. Full text.

From the Abstract. The objective of this study was to test the efficacy of a mindfulness-based breathing therapy on improving symptoms and health-related quality of life in those with chronic obstructive lung disease (COPD).

This trial found no measurable improvements in patients with COPD receiving a mindfulness-based breathing therapy compared to a support group, suggesting that this intervention is unlikely to be an important therapeutic option for those with moderate-to-severe COPD.

The effect of diaphragmatic breathing

Ma, X., et al. (2017). The effect of diaphragmatic breathing on attention, negative affect and stress in healthy adults. Frontiers in psychology, no. 8, pp. 874, https://doi.org/10.3389/fpsyg.2017.00874. Full text.

From the Abstract. A growing number of empirical studies have revealed that diaphragmatic breathing may trigger body relaxation responses and benefit both physical and mental health. However, the specific benefits of diaphragmatic breathing on mental health remain largely unknown.

The present study aimed to investigate the effect of diaphragmatic breathing on cognition, affect, and cortisol responses to stress. Forty participants were randomly assigned to either a breathing intervention group (BIG) or a control group (CG). The BIG received intensive training for 20 sessions, implemented over 8 weeks, employing a real-time feedback device, and an average respiratory rate of 4 breaths/min, while the CG did not receive this treatment. . . . 

The findings suggested that the BIG showed a significant decrease in negative affect after intervention, compared to baseline.  . . .  In conclusion, diaphragmatic breathing could improve sustained attention, affect, and cortisol levels.