Mindfulness-based interventions have gained considerable popularity in practice and in research, which has grown exponentially since the 1980s. Numerous studies and accounts have documented its social, health and workplace benefits with both clinical and non-clinical populations. Moreover, research has also demonstrated that client outcomes are improved when psychotherapists/clinicians practice mindfulness.
The benefits of mindfulness that have been identified are :
- Stress reduction
- Reduced rumination
- Decreased negative affect (e.g. depression, anxiety)
- Less emotional reactivity/more effective emotion regulation
- Increased focus
- More cognitive flexibility
- Improved working memory
Currently there are a number of different forms of mindfulness-based interventions used in the field but they are largely variants of the two basic training programs, Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy (MBCT).
Below are some details of the evidence as it pertains to various programs and health conditions, including references to studies.
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 Davis, D, and Hayes, JA, 2012. What are the Benefits of Mindfulness. American Psychological Association, Monitor on Psychology. July/August 2012 (http://www.apa.org/monitor/2012/07-08/ce-corner.aspx)
MBSR & MBCT
MBCT (Mindfulness-Based Cognitive Therapy) was developed by Zindel Segal, Mark Williams and John Teasdale. It has proven effective for preventing serious recurrent depression (depression relapse), for which it was developed. In addition, it has also been shown to be useful for acute depression and anxiety dependent up the severity of the condition. MBCT replaces some of the content of MBSR and incorporates elements of cognitive behaviour therapy. The key difference is that instead of MBSR’s focus on stress, in MBCT the focus is on turning toward low mood and negative thoughts so that participants gain experience with recognizing these symptoms as precursors to depressive relapse. The focus is on changing one’s relationship to these unwanted thoughts, feelings and body sensations so that participants no longer try to avoid them or react to them automatically, but rather respond to them in an intentional and skillful manner. Both MBSR and MBCT have now been adapted for different kinds of psychological/mental health and physical/medical conditions.
Evidence of the Effectiveness of MBSR and MBCT
The research literature on the effectiveness of Mindfulness-Based Therapies (MBTs) such as MBSR and MBCT has grown exponentially since the 1980s. Past research include a number of methodological problems that limited the validity of results: small sample sizes, lack of long term follow-up, no control comparison groups, heavily dependent on self-report outcomes, and variation in teaching of mindfulness. However, the quality of the research has improved considerably in recent years, using the gold standard of research design – the randomized control study comparing the outcomes of participants in the mindfulness intervention group with those who are in an “active control” group, i.e. the mindfulness group and the control group are the same except for the aspects of the intervention being tested.
Meta-analysis is a statistical technique for combining the findings from many independent studies and is most often used to assess the clinical effectiveness of healthcare interventions.
Overall, a review of meta-analyses found evidence that supports the use of MBSR and MBCT in alleviating both mental and physical symptoms, as an adjunct treatment of cancer, cardiovascular disease, chronic pain, depression, anxiety disorders and in prevention in healthy adults and children. 
In the below boxes are the findings from individual meta-analyses, as well as individual randomized control trials, of the effectiveness of MBSR, MBCT and other mindfulness-based interventions in treating these various health conditions.
 Gotink et al., 2015. Standardised mindfulness-based interventions in healthcare: an overview of systematic reviews and meta-analyses of RCTs. PLoS One. 2015 Apr 16;10(4):e0124344. http://dx.doi.org/10.1371/journal.pone.0124344. eCollection 2015
Stress, Anxiety & Depression
MBTs are effective treatments for anxiety and depression in cancer patients and survivors. MBT also significantly improved mindfulness skills. 
MBCT has been shown to be an effective intervention for preventing relapse in depressed patients, especially in patients who have had 3 or more previous major depressive disorder episodes and those with more severe symptoms. MBCT was shown to be as effective as maintenance anti-depressants in preventing relapse. The significance of the latter finding is that depressed patients are presented with a treatment choice other than drugs. It has also been suggested that MBT can be used in conjunction with other treatments and in other settings.     
These studies focused on preventing depression in people who were currently well. It was hypothesized that MBTs may not be effective for people who were currently experiencing symptoms. However, one meta-analysis found that MBCT provided significant benefits to people who were experiencing a current depressive episode. Benefits of MBCT have been shown to be similar to those of group CBT.
As to how mindfulness works to prevent depression relapse, one meta-analysis found that alterations in mindfulness, rumination, worry, compassion, or meta-awareness were associated with, predicted or mediated MBCT’s effect on treatment outcome. Preliminary studies also indicated that alterations in attention, memory specificity, self-discrepancy, emotional reactivity and momentary positive and negative affect might play a role in how MBCT exerts its clinical effects.
 Khoury B et al, 2013. Mindfulness-based therapy: A comprehensive meta-analysis. Clin Psychol Rev. Aug;33(6):763-71. doi: 10.1016/j.cpr.2013.05.005. Epub 2013 Jun 7. http://www.ncbi.nlm.nih.gov/pubmed/23796855
 Hoffman S, Sawyer A, Witt A, Oh D, 2010. The effect of Mindfulness-based therapy on anxiety and depression: a meta-analytic review. Journal of Consulting and Clinical Psychology, Vol 78(2), pp 169-183.
 Goyal et al, 2014. Meditation Programs for Psychological Stress and Well-Being. Comparative Effectiveness Reviews, No. 124
 Sharma, M, Rush S, 2014. Mindfulness-Based Stress Reduction as a Stress Management Intervention for Healthy Individuals: A Systematic Review. Journal of Evidence-Based Complementary & Alternative Medicine , 19:4, 271-286
 Piet, J, Wurtzen, H and Zachariae, R, 2012. The effect of mindfulness-based therapy on symptoms of anxiety and depression in adult cancer patients and survivors: A systematic review and meta-analysis. Journal of Consulting and Clinical Psychology, Vol 80(6), Dec 2012, 1007-1020. http://dx.doi.org/10.1037/a0028329
 Zainal N, Booth S a& Huppert F, 2013. The efficacy of mindfulness-based stress reduction on mental health of breast cancer patients: a meta-analysis. Psycho-Oncology, Volume 22, Issue 7, pages 1457–1465, July 2013
 H. Cramer, R. Lauche, A. Paul, G. Dobos, 2012. Mindfulness-based stress reduction for breast cancer— a systematic review and meta-analysis. Current Oncology, Vol 19, No. 5, 2012
 P Klainin-Yobas , Ma Aye A, Cho, D, 2012. Efficacy of mindfulness-based interventions on depressive symptoms among people with mental disorders: A meta-analysis. International Journal of Nursing Studies, Volume 49, Issue 1, 109–121.
 Kuyken et al, 2015. Effectiveness and cost-effectiveness of mindfulness-based cognitive therapy compared with maintenance antidepressant treatment in the prevention of depressive relapse or recurrence (PREVENT): a randomised controlled trial. The Lancet, Volume 386, No. 9988, p63–73, 4 July 2015. http://dx.doi.org/10.1016/S0140-6736(14)62222-4
 Piet J & Hougaard E, 2011. The effect of mindfulness-based cognitive therapy for prevention of relapse in recurrent major depressive disorder: A systematic review and meta-analysis. Clin Psychol Rev. Aug;31(6):1032-40. doi: 10.1016/j.cpr.2011.05.002. Epub 2011 May 15
 Segal Z. V., Williams J. M. G., & Teasdale J. D., 2002. Mindfulness-based cognitive therapy for depression: A new approach to preventing relapse. New York: Guilford.
 Williams J. M. G., Teasdale J. D., Segal Z. V., & Kabat-Zinn J., 2007. The mindful way through depression: Freeing yourself from chronic unhappiness. New York: Guilford.
 Strauss C et al., 2014.Mindfulness-Based Interventions for People Diagnosed with a Current Episode of an Anxiety or Depressive Disorder: A Meta-Analysis of Randomised Controlled Trials. Article in PLoS ONE 9(4):e96110 · April 2014 Impact Factor: 3.23 http://dx.doi.org/10.1371/journal.pone.0096110 · Source: PubMed
 Van der Velden AM et al., 2015. A systematic review of mechanisms of change in mindfulness-based cognitive therapy in the treatment of recurrent major depressive disorder. Clin Psychol Rev. Apr;37:26-39. doi: 10.1016/j.cpr.2015.02.001. Epub 2015 Feb 11
An 8-week mindfulness program was found to be effective for youth with ADHD aged 11-15. After mindfulness training, adolescents’ attention and behavior problems reduced, their executive functioning improved, as indicated by self-report measures as well as by father and teacher report. Improvements in actual performance on attention tests were also found. Effects of mindfulness training became stronger at 8-week follow-up, but waned at 16-week follow-up. The study suggests that mindfulness training for adolescents with ADHD (and their parents) is an effective approach, but maintenance strategies need to be further developed.
One randomized trial showed that an MBCT program for children was a promising intervention for attention and behaviour problems, and may reduce childhood anxiety.
 Zoogman et al., 2015. Mindfulness Interventions with Youth: A Meta-Analysis. Mindfulness, April Volume 6, Issue 2, pp 290-302
 Van de Weijer-Bergsma et. al., 2012. The Effectiveness of Mindfulness Training on Behavioral Problems and Attentional Functioning in Adolescents with ADHD. J Child Fam Stud 21:775–787 http://dx.doi.org/10.1007/s10826-011-9531-7
 Semple R et al., 2010. A Randomized Trial of Mindfulness-Based Cognitive Therapy for Children: Promoting Mindful Attention to Enhance Social-Emotional Resiliency in Children. Journal of Child and Family Studies, 19:2, 218-229
Emotional distress is a common co-morbid condition of diabetes. Approximately 20 to 40% of people with type 1 or type 2 diabetes are affected by emotional distress, which can consist of symptoms of depression, anxiety, and diabetes-specific distress. Emotional distress has been shown to result in a lower quality of life. In addition, depression is associated with suboptimal self-care behaviors, suboptimal glycemic control, adverse cardiovascular outcomes, and higher mortality rates. Although the emotional problems in diabetic patients have received increasing attention in the last decade, they are still often not recognized in clinical practice and remain untreated.
One randomized control trial has shown that MBCT is more effective than treatment as usual in reducing stress, depressive symptoms, and anxiety, and in improving quality of life, both mental and physical. However, the authors found no significant effect on HbA1c (glycated haemoglobin) or diabetes-specific distress. Nevertheless patients with elevated diabetes distress in the MBCT group did show a decrease in diabetes distress (P = 0.07, d = 0.70) compared with the control group.
 Grigsby et al., 2002.Prevalence of anxiety in adults with diabetes: a systematic review. J Psychosom Res; 53:1053–1060. pmid:12479986
 Gonzalez JS, et al. 2008. Depression and diabetes treatment nonadherence: a meta-analysis. Diabetes Care 31:2398–2403, pmid:19033420OpenUrl
 Lustman PJ et al. 2000. Depression and poor glycemic control: a meta-analytic review of the literature. Diabetes Care. 23:934–942pmid:10895843
 Bogner HR et al. 2007. Diabetes, depression, and death: a randomized controlled trial of a depression treatment program for older adults based in primary care (PROSPECT). Diabetes Care. 30:3005–3010pmid:17717284
 Jenny van Son, et al., 2013.The Effects of a Mindfulness-Based Intervention on Emotional Distress, Quality of Life, and HbA1c in Outpatients With Diabetes (DiaMind). Diabetes Care. Apr; 36(4): 823-830. http://dx.doi.org/10.2337/dc12-1477
 MacBeth A, A Gumley, 2012. Exploring compassion: A meta-analysis of the association between self-compassion and psychopathology. Clinical Psychological Review. 32: 545- 552.
 Shapiro, S, K Brown, G Biegel. Teaching self-care to caregivers: Effects of mindfulness-based stress reduction on the mental health of therapists in training.Training and Education in Professional Psychology, Vol 1(2), May 2007, 105-115. http://dx.doi.org/10.1037/1931-39184.108.40.206
 Farb NAS, Segal ZV, Anderson AK (2013). Mindfulness meditation training alters cortical representations of interoceptive attention. Social, Cognitive and Affective Neuroscience, 8(1), 15-26. (Supplementary Materials)
 Farb NAS, Segal ZV, Anderson AK (2013). Attentional Modulation of Primary Interoceptive and Exteroceptive Cortices. Cerebral Cortex, 23(1), 114-26.
 Farb NAS, Segal ZV, Mayberg H, Bean J, McKeon D, Fatima Z, Anderson AK (2007). Attending to the present: mindfulness meditation reveals distinct neural modes of self-reference. Social Cognitive and Affective Neuroscience, 2(4), 313-122. (PDF)
 Fox K et al., 2014. Is meditation associated with altered brain structure? A systematic review and meta-analysis of morphometric neuroimaging in meditation practitioners. Neurosci Biobehav Rev. Jun;43:48-73. http://dx.doi.org/10.1016/j.neubiorev.2014.03.016. Epub 2014 Apr 3.
 Gerucci, Pappaianni, Siugzdaite, Theuninck, & Job, 2015. Mindful Emotion Regulation: Exploring the Neurocognitive Mechanisms behind Mindfulness. BioMed Research International, Volume 2015 (2015), Article ID 670724, 9 pages. http://dx.doi.org/10.1155/2015/670724
 Witkiewitz K, Lustyk M, & Bowen S, 2012/ Re-Training the Addicted Brain: A review of hypothsized neurobiolgical meechanisms ofmindfulness-based relapse prevention. Psychol Addict Behav. 27(2) p 351-365. Published online 2012 Jul 9. http://dx.doi.org/10.1037/a0029258
MBSR may also be an effective treatment option for adults with chronic low back pain. MBSR or CBT, compared with usual care, resulted in greater improvement in back pain and functional limitations at 26 weeks, with no significant differences in outcomes between MBSR and CBT. 
Neuroimaging evidence reveals that mindfulness meditation-related pain relief is associated with unique appraisal cognitive processes (personal interpretation of a situation) depending on expertise level and meditation tradition. Mindfulness meditation-related pain relief may share a common final pathway with other cognitive techniques in the modulation of pain.
 Reiner K, Tibi L, Lipsitz J, 2013. Do mindfulness-based interventions reduce pain intensity? A critical review of the literature. Pain Med. Feb;14(2):230-42. doi: 10.1111/pme.12006. Epub 2012 Dec 13.
 Parth Rajguru et at., 2014. Use of Mindfulness Meditation in the Management of Chronic Pain: A Systematic Review of Randomized Controlled Trials. American Journal of Lifestyle Medicine February 21.
 Cherkin D et al, 2016. Effect of Mindfulness-Based Stress Reduction vs Cognitive Behavioral Therapy or Usual Care on Back Pain and Functional Limitations in Adults With Chronic Low Back Pain: A Randomized Clinical Trial. JAMA. 2016;315(12):1240-1249. http://dx.doi.org/10.1001/jama.2016.2323
 Zeidan F et al., 2012. Mindfulness meditation-related pain relief: Evidence for unique brain mechanisms in the regulation of pain. Neurosci Lett. 2012 Jun 29; 520(2): 165–173. Published online 2012 Apr 6. http://dx.doi.org/10.1016/j.neulet.2012.03.082
Following transient ischemic attack/stroke, evidence points to the benefits of MBT across a range of psychological, physiological and psychosocial outcomes, which include anxiety, depression, mental fatigue, blood pressure, perceived health and quality of life. However, better research is needed.
 Abbott, R et al., 2014. Effectiveness of mindfulness-based stress reduction and mindfulness based cognitive therapy in vascular disease: A systematic review and meta-analysis of randomised controlled trials. Journal of Psychosomatic Research.Vol76 (5), p 341-351
 Lawrence M et al, 2013. A systematic review of the benefits of mindfulness-based interventions following transient ischemic attack and stroke. Int J Stroke. Aug; 8(6):465-74. doi: http://dx.doi.org/10.1111/ijs.12135