There are nearly 700 published experimental trials assessing meditation-based interventions. Most of the research examines the efficacy of MBSR programs, but there are also studies of MBCT, other MBSR-derived programs, and shorter mindfulness interventions. Two meta-analyses of MBSR show average effect sizes of 0.5–0.6. The most comprehensive meta-analysis found mindfulness-based treatments to be especially effective for reducing symptoms of anxiety, depression, and stress. Most of the research has been in the mindfulness-based interventions outlined below.
A. Cancer-Related Symptoms
There are over 60 clinical trials of mindfulness meditation in patients with cancer. Over two dozen studies have all shown significant improvements in a variety of outcomes such as mood disturbance, anxiety, stress, and quality of life. Three meta-analyses and a systematic review corroborate the beneficial mental health effect of mind-body therapies in cancer patients. From this review's conclusion, these therapies show efficacy in treating common cancer-related side effects, including nausea and vomiting, pain, fatigue, anxiety, and depressive symptoms, and improving overall quality of life. In addition, some studies have shown effects on biomarkers such as immune function and stress hormones. A 2020 meta-analysis that included over 3000 adults with a cancer diagnosis found that mindfulness-based interventions were associated with reductions in anxiety for at least 6 months after the intervention. Clinical studies support the role of mind-body therapies in dealing with common experiences that cause distress around cancer diagnosis, treatment, and survivorship including loss of control, uncertainty about the future, fears of recurrence, and a range of physical and psychological symptoms. Studies also supports their cost-effectiveness. Finally, online and mobile adaptations being developed and evaluated increase promise for use in a global context. Although over 1000 mobile application platforms are available, only 2% of mobile applications are supported by original clinical research. A 2021 meta-analysis of 34 RCTs involving 7566 participants examined the efficacy of digital applications of mindfulness meditation. They found small to moderate but significant reduction of perceived stress, anxiety symptoms, and depression symptoms. While more carefully designed studies need to be conducted, there appears to be utility for these modalities as an adjunctive part of overall care.
In the past decade, there have been over a hundred clinical trials that examined mind-body therapies in the treatment of primary depression, or depression in the context of another major medical illness. Ten studies, including 7 RCTs, examined the effect of MBCT on patients with major depression. Several trials demonstrated a near 50% reduction in relapses in patients with a prior history of more than two relapses. One study comparing MBCT with standard CBT found the two modalities to be equally effective in treatment of recurrent depression. A 2021 meta-analysis of 19 studies involving 1076 adults aged 65 years or older with depression found significantly improved depression compared with controls. MBCT is recommended as a treatment for recurrent depression in the United Kingdom's National Institute for Clinical Guidelines.
C. Anxiety and Stress Disorders
Several RCTs have shown benefit in anxiety and stress disorders. A 2021 systematic review and meta-analysis studied 23 RCTs examining acceptance and commitment therapy (ACT), MBCT, and MBSR, including 1815 patients with a clinical diagnosis of an anxiety disorder. While there are clinically relevant short-term anxiolytic effects, heterogeneity of the studies and inadequate control groups preclude firm conclusions. There are no noninferiority trials comparing mindfulness meditation with standard psychotherapies.
Numerous studies have examined meditation-based intervention in chronic pain populations. Most studies showed significant improvement in mental health parameters, such as quality of life, acceptance, pain tolerance, and mood. A 2018 meta-analysis and systematic review of 13 studies concluded that mindfulness meditation has prominent effects on the psychological aspects on living with chronic pain, improving associated depression and quality of life. One follow-up study showed that improvements were maintained up to 4 years later. An RCT of MBSR for patients with rheumatoid arthritis showed improvement in psychological distress and well-being at 6-month follow-up despite no improvement in disease activity. A second RCT of patients with rheumatoid arthritis compared a mindfulness-based intervention (that was much less intensive than standard MBSR) with a CBT intervention and an education control group. Both experimental groups were significantly superior to the control group, although overall the CBT group showed the greatest reduction in pain and interleukin-6 levels. In the subset of patients with a history of recurrent depression, however, the mindfulness-based intervention yielded greatest reduction in pain and improvement in mood. An RCT comparing MBSR with CBT in 342 people with chronic low back pain found that MBSR or CBT, compared with usual care, both resulted in significant improvement in back pain and functional limitations at 26 weeks, with no significant differences in outcomes between MBSR and CBT. Study authors concluded that MBSR is an effective treatment option for patients with chronic low back pain. A 2019 systematic review and meta-analysis including over 6000 patients found that mind-body therapies were associated with pain reduction and reduced opioid use. This study concluded that mind-body therapies are an important tool for addressing the opioid crisis.
Other studies have been conducted involving patients with chronic insomnia, psoriasis, tinnitus, irritable bowel syndrome, inflammatory arthritis, type 2 diabetes mellitus, organ transplants, eating disorders, hot flashes, and female sexual arousal disorder, as well as with inner city residents, nursing home residents, incarcerated individuals, smokers, physicians, nurses and nursing students, medical students, and college students. Nearly all these studies showed a mental health benefit from meditation, and most showed symptom reduction of the condition being studied. An RCT of psychotherapists in training showed improvement in the patients of those therapists who were taught mindfulness, and a multicenter study of physicians showed greater patient satisfaction with physicians who had higher mindfulness scores.
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et al. Association of mindfulness-based interventions with anxiety severity in adults with cancer: a systematic review and meta-analysis. JAMA Netw Open. 2020;3:e2012598.
et al. Effects of mindfulness meditation interventions on depression in older adults: a meta-analysis. Aging Ment Health. 2021;25:1181.