Qigong and Tai-Chi for Mood Regulation

Previous research has examined potential psychological mechanisms of the beneficial effects of mindfulness. On the basis of self-report of meditation practitioners, Baer et al. (20) proposed that mindfulness includes five facets of mindfulness, or five component skills: observing, describing, acting with awareness, nonjudging of inner experience, and nonreactivity to inner experience. Later, Baer et al. developed the 39-item Five Facet Mindfulness Questionnaire (FFMQ) to measure these five facets, and they validated the construct validity of the FFMQ and demonstrated that most mindfulness facets were significantly related to meditation experience. Several of the facets contributed independently to the prediction of psychological symptoms and significantly mediated the relationship between meditation experience and well-being.

Shapiro and colleagues (21, 22) proposed a different psychological model of the mechanisms of mindfulness on health-related outcomes. Shapiro suggested that mindfulness is primarily reperceiving. Like the concept of decentering (23), reperceiving is a shift in perspective associated with decreased attachment to one’s thoughts and emotions. Reperceiving was posited to lead to changes in at least four psychological mechanisms: values clarification, exposure, self-regulation, and cognitive flexibility. Values clarification involves identifying one’s important personal values, with the intention of increasing values-consistent behaviors. Exposure, similar to distress tolerance, refers to the ability to endure and “stay with” negative emotional states. Self-regulation refers to the ability to monitor and adapt one’s behavior to changing circumstances to achieve relevant goals. Cognitive flexibility is described as the ability to process important available information in one’s environment to produce adaptive behavioral responses. Feldman et al. (24) studied a sample of novice meditators and showed that mindfulness practice, compared with other stress reduction techniques, led to increased decentering and supported Shapiro et al.’s model.

Multiple studies have examined the effects of mindfulness on psychological outcomes. Carmody et al. (25) examined community adults who participated in an 8-week mindfulness-based stress reduction course and found that decentering in Shapiro et al.’s (21) model correlated strongly with the change in mindfulness as assessed by a total score of the FFMQ. Moreover, the change in composite decentering and mindfulness scores from before to after the mindfulness-based stress reduction course predicted the improvement in a wide range of psychological symptoms. Brown et al. (26) studied 944 college students using the five facets of mindfulness and found significant double-mediated associations in the expected directions for stress, anxiety, and depressive symptoms. They concluded that the five facets of mindfulness partially mediate the associations among mindfulness and psychological health outcomes. Despite results showing that decentering and other specific mechanisms did not fully mediate the associations among mindfulness facets and psychological health outcomes, both the five facet mindfulness model and Shapiro et al.’s decentering model provide important information regarding the components of mindfulness that acts as the basis for further research on how each of these components predicts health outcomes.

During the stress response, the hypothalamus-pituitary-adrenal (HPA) axis is triggered. Initiated by an excited amygdala, the hypothalamus is triggered to activate the pituitary gland to secret the adrenocorticotropic hormone, which stimulates the adrenal cortex to produce cortisol. Cortisol increases blood pressure and blood sugar levels, turns fatty acids into energy, and suppresses the immune system. At the same time, stress triggers the sympathetic nervous system to stimulate the adrenal medulla to produce catecholamine hormones, such as adrenaline (epinephrine) or noradrenaline (norepinephrine). This pathway prepares the body for violent muscular action. The sympathetic nervous system also leads to pupillary dilation, increased heart rate and blood pressure, bronchial dilatation, and decreased movement of the large intestine. People who have chronic HPA axis and sympathetic tone activation tend to develop muscle tension, headache, upset stomach, racing heartbeat, and shallow breathing among a range of other physical, emotional, and behavioral symptoms.

Benson et al. (27) studied the physiological changes during meditation and found that meditation counteracts many of the stress responses, presumably by activating the parasympathetic nervous system. Benson coined the physical state of deep relaxation, achievable by meditation, as the “relaxation response.” Subsequent research has shown that regular use of the relaxation response can help health problems that are caused or exacerbated by chronic stress, such as fibromyalgia, gastrointestinal ailments, insomnia, hypertension, anxiety disorders. Meditative movements such as Tai-Chi and Qigong, among other methods such as visualization, progressive muscle relaxation, energy healing, acupuncture, massage, and breathing techniques, are effective ways to elicit the relaxation response to counteract the stress response mediated by the HPA axis and to alleviate many of the stress-related mood symptoms. People who meditate regularly enjoy lower stress levels, increased well-being, and even lowered blood pressure and resting heart rate.

On the basis of systematic reviews of the functional and structural magnetic resonance imaging studies that have been published to date, Tang et al. (28) summarized that the anterior cingulate cortex, prefrontal frontal cortex, posterior cingulate cortex, insula, striatum (caudate and putamen), and amygdala seem to show consistent changes associated with mindfulness meditation. The brain region to which the effects of mindfulness training on attention is most consistently linked is the anterior cingulate cortex and striatum; emotion regulation is linked to multiple prefrontal regions, the limbic system, and striatum; and self-awareness is linked to the insula, medial prefrontal cortex, posterior cingulate cortex, and precuneus. It was suggested that these regions of activity might represent a core cortical network for the meditative state independent of the meditation technique (29–32). Studies have also shown that moderate to severe stress seems to increase the volume of the amygdala but reduce the volume of the prefrontal cortex and hippocampus (33). Mindfulness training, however, has been shown to enhance gray-matter density in the hippocampus (34) and to attenuate perceived stress that was correlated with reductions in amygdala gray-matter density (35). These findings suggest that mindfulness meditation might be a potential intervention and prevention strategy for emotion regulation. Mindfulness meditation might also directly modulate stress reactions in the brain via a “bottom-up” pathway, through which it alters the sympathetic-adrenal-medullary and HPA axes by increasing activity in the parasympathetic nervous system and counteracting activation of the sympathetic nervous system from stress responses to, subsequently, decrease stress-associated mood symptoms (36, 37).

It is broadly accepted that visceral sensations can contribute to many emotions. Many body-based contemplative practices involve explicit direction of attention to interoceptive sensations (38). Modern scientific definitions conceptualize mindfulness as an open, engaged, and nonjudgmental awareness of the ongoing flux of present moment experience, including internal experiences of sensations, thoughts, and feelings as well as exteroceptive sensations. It has been argued that one of the primary means by which mindfulness benefits its practitioners is by anchoring attention to interoceptive signals such as the breath or body sensation (39). Meditative practice with a focus on the sensation of the breath or interoceptive cues results in enhanced sensitivity to subtle emotion provocation. Contemplative practices that attend to interoceptive sensations enhance nonreactivity to aversive thoughts and impulses and provide time for autonomic processes to restore homeostasis and for generating adaptive regulatory insights (40).

Although many meditation types include breathing training, breathing can be applied as a separate intervention with its own effects on health and emotional outcomes. Pranayamic breathing, defined as a manipulation of breath movement, has been shown to contribute to significant physiological changes. The mechanisms of pranayamic breathing that specifically interact with the nervous system and affect metabolism and autonomic functions remain unclear. Jerath et al. (41) hypothesized that voluntary slow deep breathing functionally resets the autonomic nervous system through stretch-induced inhibitory signals and hyperpolarization currents propagated through both neural and nonneural tissue, which synchronize neural elements in the heart, lungs, limbic system, and cortex.

Slow pranayamic breathing, characterized as regular slow-frequency respiration with long periods of breath retention, has been known to cause short- and long-term changes in physiology. Both changes indicate a dynamic alteration of the autonomic system. Short-term effects of slow pranayamic breathing include increased galvanic skin resistance (a nonneural response) (42), decreased oxygen consumption (43), decreased heart rate, decreased blood pressure (44), and increased amplitude of theta waves (45). Increased theta amplitude and delta waves during breath retention and slow breathing indicate a parasympathetic state, whereas increased alpha and beta waves signify activity. One long-term effect of pranayamic breathing is the improvement in autonomic function (44); specifically, with slow breathing pranayama there is a noted increase in parasympathetic activity and a decrease in sympathetic dominance (46). Several forms of meditation, including Qigong, mindfulness meditation, and transcendental meditation, have been shown to inhibit the sympathetic nervous system and to enhance function of the immune system (47–55).

A decrease in breathing rate alone, without breath retention, can increase synchronization of brain waves eliciting delta wave activity (56). In a recent study, Zhang et al. (57) demonstrated that decreased, slow, regular breathing (from 14 breaths per minute to 10 breaths per minute) reduced blood pressure, lengthened pulse transit time, and increased cardiorespiratory coherence. These results indicate a shift toward parasympathetic dominance and positive emotion states.

Epigenetics often refers to changes in a chromosome that affect gene activity and expression, and such phenotypic changes are heritable and do not derive from a modification of the genome. These effects on cellular and physiological phenotypic traits may result from external or environmental factors or be part of the normal developmental process.

Bhasin et al. (58) studied the genomic changes during one session of relaxation response (meditation) practice among healthy practitioners with years of experience and in novices before and after eight weeks of relaxation response training. They measured the transcriptome in peripheral blood before, immediately after, and 15 minutes after listening to a guided imagery recording. They reported that both short- and long-term practitioners showed significant temporal gene expression changes compared with novices, with long-term practitioners showing greater differences. Relaxation response practice enhanced expression of genes associated with energy metabolism, mitochondrial function, insulin secretion, and telomere maintenance and reduced expression of genes linked to inflammatory response and stress-related pathways. The researchers posited that relaxation response practice promotes mitochondrial resiliency and may be important at the cellular level for the downstream health benefits associated with reducing psychosocial stress.

An increasing number of studies have demonstrated the effectiveness of Qigong exercise in helping people reduce anxiety and depressive symptoms and improve psychological well-being. The effect of Qigong has been found to be comparable with that of cognitive-behavioral therapy in significantly reducing depressive symptoms among outpatients with clinical depression (59) and adults with depressive symptoms (60). Compared with walking or conventional exercise, one study suggested a beneficial effect of Qigong exercise in reduction of depressive symptoms among women with perimenopausal syndrome and depression (61), and another study showed that Qigong and conventional exercise have similar effects on reducing depressive symptoms among patients with hypertension and depression (62).

In two studies, the Qigong group had significant reduction in depressive symptoms among older adults with depression and a chronic medical illness when compared with a control group who read the newspaper together (63, 64); the Qigong group also had significant reduction in depressive symptoms among patients with type 2 diabetes mellitus when compared with people in the control group who received education and performed stretching (65). When compared with a waitlist control group, some studies have demonstrated favorable effects of Qigong on reducing depressive symptoms among persons with chronic fatigue syndrome-like illnesses (66, 67), type 2 diabetes mellitus (68), subhealth problems (69), and Parkinson’s disease (70). Two studies showed that there were no significant beneficial effects of Qigong for patients with burnout using basic care as a control (71) and for older adults with chronic physical illnesses using traditional remedial rehabilitation activities as a control (72).

Compared with depressive symptoms, few studies have been performed on the effects of Qigong on anxiety symptoms. There is evidence suggesting that Qigong could alleviate anxiety symptoms among people with subhealth problems compared with a control group (69). However, Qigong showed no significant benefits among people with mild essential hypertension when compared with conventional exercise and among people with burnout when compared with basic care (62, 71).

Existing systematic reviews have documented the clinical evidence of the beneficial effects of Qigong exercise on depressive and anxiety symptoms among patients with chronic diseases (73–75). A meta-analysis study that reviewed 12 randomized controlled trials (RCTs) (73) suggested that Qigong exercise has beneficial effects on depressive symptoms when compared with a waitlist control group or a usual care only group. However, available evidence does not suggest beneficial effects of Qigong exercise on anxiety symptoms. Another meta-analysis study (74) based on patients with type 2 diabetes suggested that Qigong was effective in reducing depression and anxiety. Oh et al. (75) performed another systematic review of Qigong that suggested potential effects of Qigong exercise in the treatment of depression. The three reviews described earlier in this paragraph reported that Qigong was beneficial for the management of depressive symptoms. A review of Qigong exercise in healthy adults by Wang et al. (76) suggested that Qigong exercise may reduce stress and anxiety.

The inconsistent results of the effects of Qigong in these reviews are probably due to the great heterogeneity of participants, wide spectrum of outcomes, different measurements for depression and anxiety, and different types of control groups. These reviews involved diverse participants, including healthy individuals, individuals with depression, and individuals with chronic diseases, and a wide spectrum of outcomes, including mood, anxiety, depression, psychological well-being, self-efficacy, and quality of life. The depression symptoms were measured by a variety of measurement scales, making comparison across studies difficult.

In addition to depressive and anxiety symptoms, we found that Qigong exercise was also associated with significant improvements in general health (blood pressure, bodily pain, gastrointestinal health, dynamic balance, right-hand grip strength, fatigue, and sleep quality), psychological health (concentration, memory, burnout, and self-efficacy), social relation, and health-related quality of life (59, 62–64, 67, 69, 71, 72, 77–79).

A previous study reported that a decreasing trend of salivary cortisol level was observed following Qigong intervention, but there was no significant change for the blood serotonin level (63). Qigong was found to increase melatonin level, enhance cellular function of neutrophil and natural killer cells (80), and reduce inflammation among cancer patients (79). Studies on chronic fatigue syndrome indicated that Qigong exercise may reduce salivary cortisol and enhance telomerase activity in the blood, suggesting the regulation of HPA activity and antiaging effects of Qigong exercise (78, 81). A recent animal model has demonstrated the significant role of adiponectin in mediating running-triggered enhancement of hippocampal neurogenesis and in alleviating depression (82). The findings of a study on women with chronic fatigue syndrome-like illness echoed the above findings in mice, indicating that Qigong exercise significantly reduced depressive symptoms and improved the levels of adiponectin and that adiponectin might contribute to the antidepressive effects of Qigong exercise (83).

A growing body of clinical research has investigated the effects of Tai-Chi for a variety of health issues. Tai-Chi has been shown to have significant effects in reducing depressive symptoms in fibromyalgia (84), knee osteoarthritis (85), and rheumatoid arthritis (86) compared with wellness education and stretching, and also in rheumatoid arthritis (87) when compared with an attention control group (education on nutrition and medical information). In a systematic review, nine RCTs and four nonrandomized comparison studies examined the effects of Tai-Chi on depression, education, routine activity, and other forms of exercise by using self-comparison among individuals with rheumatoid arthritis, osteoarthritis, fibromyalgia, and depression; women with sedentary lifestyles and obesity; Chinese older adults with cardiovascular disease risk factors; and healthy adults. Only two studies investigated participants with clinical depression. The overall findings suggested that Tai-Chi exercise had significant depression-reduction effects compared with various control groups (88). In the same review, a meta-analysis based on two RCTs and six nonrandomized comparison studies, including healthy adults, patients with symptomatic osteoarthritis, older adults with cardiovascular disease risk factors, adolescents with attention-deficit hyperactivity disorder, and individuals with fibromyalgia, reported that Tai-Chi was associated with a significant reduction in anxiety (88).

Another recent review including 37 RCTs demonstrated that Tai-Chi interventions have beneficial effects for various populations on a range of psychological well-being measures, including depression, anxiety, stress and mood disturbance, self-esteem, and exercise efficacy (89). An earlier review of 13 studies also showed that Tai-Chi appeared to be most significant on depression (nine studies), anxiety (six studies), and mood (four studies) (90). Interestingly, a systematic review comparing the effects of Qigong and Tai-Chi on depressive symptoms suggested that Qigong appears to be beneficial for reducing depressive symptom severity, but no significant effects were seen for Tai-Chi (91).