e4-07: Meditation

Meditation is a broad term that incorporates features of self-regulation, awareness, attention, and presence that is typically cultivated through an intentional practice. In lay contexts, the word "mindfulness" is often interchanged with or joined to "meditation." This reflects the ambiguity in interpreting these words and their cultural origins. In health care settings, one popular application of mindfulness meditation is the mindfulness-based stress reduction (MBSR) program. This program and its derivatives have been extensively studied in medical populations.

The essential exercise of meditation is focusing a person's full attention on a designated object of meditation, such as his or her breath. When the person notices that the mind has wandered from this object, attention is returned to the object. Training the mind, beginning with this basic exercise, has many effects including relaxation, metacognition, cognitive flexibility, uncoupling of painful physical sensations from maladaptive cognitive patterns, and revelation of previously subconscious content. In meditation practices, after initial training with the breath, the objects of meditation can include other aspects of human experience, such as physical sensations (eg, pain) or mental and emotional states (eg, anxiety).

In 1979, mindfulness meditation practice was introduced into US medical settings with the development of the MBSR program by Jon Kabat-Zinn, PhD. It is an 8-week program that introduces mindfulness practice in a secular, practical form to participants in the context of their life circumstances. This program is intended to create a deliberate, sustained, nonjudgmental way of paying attention to one's experience to enhance self-awareness, change maladaptive thinking, increase the capacity for skillful response to challenges, and reduce suffering. There are now hundreds of MBSR programs in the United States and other countries. A close derivative of MBSR, mindfulness-based cognitive therapy (MBCT), was developed exclusively for people with recurrent major depression and has been widely applied to other psychiatric populations. These programs have also been adapted for use in patients with borderline personality disorder (Dialectical Behavior Therapy), eating disorders, substance use disorders (mindfulness-based relapse prevention), and childbirth preparation.

There have been extensive cardiac, respiratory, metabolic, endocrine, and central nervous system studies of individuals during meditation. Though much remains unknown, meditation works in part through modulation of the autonomic nervous system, as demonstrated in the late 1960s and early 1970s by Dr. Herbert Benson. Its effects differ from sleep. From a psychological perspective, it is thought that meditation enables the mind to establish a stable platform from which all events in the field of awareness can be viewed (eg, emotions, thoughts, physical sensations) without reactivity. Meditation practices include metacognition, exposure, uncoupling of maladaptive thoughts from physical stimuli (eg, pain), enhancing cognitive flexibility, relaxation, and self-regulation. At the physiologic level, studies of meditation have found effects on the immune system (increased antibody response to vaccination, reduction in pro-inflammatory cytokines, possible slowed decline of CD4+ lymphocytes in HIV infection), nervous system (enhanced cortical thickness in specific brain regions; enhanced prefrontal activation on electroencephalogram; neuroplastic changes in the anterior cingulate cortex, insula, temporo-parietal junction, and fronto-limbic network; characteristic functional MRI findings), and endocrine system (reduced cortisol, increased melatonin levels). There are also changes seen at the cellular level (telomere length) epigenetic changes (gene expression) and changes in the microbiome.

There are few reported adverse effects of meditation specifically reported in experimental trials. For example, meditation can allow previously subconscious, distressing psychic content to come into consciousness. Patients with psychiatric disorders should consult with a mental health care professional before starting a program of meditation. Some expert researchers in meditation and mindfulness have sought more critical inquiry into the adverse effects associated with these practices and to be careful that these practices do not degrade into a panacea for all.

Untreated psychosis, mania, and active substance abuse are relative contraindications because these conditions may impair the fundamental exercise required for meditation (ie, repeatedly returning one's attention to a desired object of awareness).

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.

B. Depression

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.

D. Chronic Pain

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.

F. Other Conditions

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.