Qigong and Tai-Chi for Mood Regulation

Qigong and Tai-Chi have been shown to improve psychological well-being and reduce symptoms of anxiety and depression by altering the autonomic system and restoring homeostasis. These effects could occur through changes in multiple prefrontal regions, the limbic system, and the striatum or in the expression of genes linked to inflammatory responses and stress-related pathways.

Abstract

Qigong and Tai-Chi are traditional self-healing, self-cultivation exercises originating in ancient China. These exercises are characterized by coordinated body posture and movements, deep rhythmic breathing, meditation, and mental focus based on traditional Chinese medicine theories. Although the exact mechanisms of Qigong’s and Tai-Chi’s effects on physical and mental well-being are unknown, these practices may be viewed as meditative movements and share many of the healing elements observed in mindfulness meditation. Clinical studies including randomized controlled trials and meta-analyses have shown that both Qigong and Tai-Chi have beneficial effects on psychological well-being and reduce symptoms of anxiety and depression. Qigong and Tai-Chi frequently involve anchoring attention to interoceptive sensations related to breath or other parts of the body, which has been shown to enhance nonreactivity to aversive thoughts and impulses. Preliminary studies suggest that the slow movements in Qigong and Tai-Chi with slowing of breath frequency could alter the autonomic system and restore homeostasis, attenuating stress related to hypothalamus-pituitary-adrenal axis reactivity and modulating the balance of the autonomic nervous system toward parasympathetic dominance. Qigong’s and Tai-Chi’s effects on emotion regulation could occur through changes in multiple prefrontal regions, the limbic system, and the striatum or in the expression of genes linked to inflammatory responses and stress-related pathways.

What Are Qigong and Tai-Chi?

Qigong and Tai-Chi are traditional self-healing, meditation, and self-cultivation exercises originating in ancient China. The practice, which is rooted in traditional Chinese medicine (TCM) theories, is characterized by coordinated body posture and movements, deep rhythmic breathing, meditation, and mental focus (1).

Qigong is a general term for a large variety of exercises and therapies practiced by generations of Chinese for centuries for health and longevity. The word Qigong is composed of two Chinese words: Qi and Gong. Qi refers to the vital energy, or life force, that is inherent in all forms of life. Gong refers to any committed practice that requires hard work and sustained effort. Qigong, therefore, means “energy practice” or “energy cultivation” (www.qigongchicago.com). Qigong may roughly be divided into two categories: one includes bodily movement (movement Qigong), and the other includes simply sitting or standing meditation with no added bodily movements (static Qigong). Qigong emerged from the following five major traditions: Confucian, Buddhist, Daoist, medicine, and martial arts. Each of these five traditions has its own training or practice purposes, in addition to using different methods to achieve these purposes. Confucian Qigong aims at cultivating gentleman-like character through the awareness of morality. Buddhist Qigong emphasizes the cultivation of virtue and enlightening wisdom. Daoist Qigong claims to provide a way to achieve longevity and spiritual enlightenment as well as a closer connection with the natural world. Martial art Qigong emphasizes the building up of body strength for fighting and defense. Lastly, medical (or health) Qigong focuses on improving physical and mental well-being or on treating illnesses. In this article, we use Qigong and health Qigong interchangeably because we are most interested in Qigong’s effects on mood regulation.

Tai-Chi is a widely practiced Chinese martial art tracing back to its origin in the 17th century. It typically involves more complex and choreographed movements that are coordinated with one’s breath, which is used for cultivating health and self-defense. Tai-Chi is a soft style martial art characterized by leveraging, coordinating, and relaxing the joints, rather than muscular tension, to neutralize, yield, or initiate attacks. Because calmness is a core tenant of Tai-Chi and the practice uses a meditative approach to cultivate Qi, it is frequently considered a form of medical or health Qigong. Both Qigong and Tai-Chi can be categorized as meditative movements or practices with a focus of mind, movement, breathing, and attaining a deeply relaxed state (2).

According to TCM, poor health is caused by stagnant Qi or a blockage of Qi inside the body. Both Tai-Chi and Qigong enhance the flow of Qi in the body and dissolve any blockage that might create stagnant Qi to restore health. To move Qi inside the body, practitioners use intent or imagery training to guide the flow of Qi in the directions of the meridians described by TCM theories. Experienced Qigong and Tai-Chi practitioners frequently claim that they can feel the sensation of Qi flowing in their bodies.

Both health Qigong and Tai-Chi enjoy increasing popularity worldwide and are widely practiced by people of all ages. Largely, individuals who practice Qigong or Tai-Chi do so to promote physical and psychological well-being and to treat various health conditions (3, 4). A study conducted by Kachan et al. (5) investigated the prevalence of mindfulness-based practices in the U.S. workforce and estimated that 131 million practitioners took part in at least one mind-body exercise (Tai-Chi, health Qigong, yoga, breathing technique, and Pilates) in the past year.

History and the Development of Health Qigong and Tai-Chi in China

The origin of health Qigong dates to more than 4,000 years ago. In ancient China, knowledge about both Qigong and Tai-Chi was passed down from sophisticated masters to students in their family lineage as a form of secretive and esoteric self-training. They were exercises created by TCM doctors to promote longevity and health (6, 7). In the late 1940s, the Chinese government consolidated a wide range of self-cultivating and self-healing practices under the category of Qigong. During the Great Leap Forward and Cultural Revolution (from 1958 to 1963), Qigong practice was allowed only in state-run rehabilitation centers and hospitals under supervision. After the Cultural Revolution, the practice of Qigong was revitalized and encouraged by the Chinese government. A rough estimate of 200 million Chinese individuals between 1976 and 1990 participated in Qigong and Tai-Chi practices (8). Along with the surge in Qigong popularity, some claimed to possess supernatural power by using Qigong practice. These individuals drew significant influence and attracted sizable believers. Subsequently, the Chinese government banned all activities related to Qigong. It was not until 2000 that the prohibition was relaxed and the Chinese Health Qigong Association was established to standardize Qigong practice (9). Since then, only state-approved health Qigong can be practiced with the supervision of certified health Qigong instructors (10). The standardization and public promotion of Qigong and Tai-Chi by the Chinese Health Qigong Association have facilitated their dissemination, both in China and worldwide.

Types of Modern Health Qigong and Tai-Chi

There are a great number of health Qigong forms developed by various teachers and training schools in Chinese society throughout history. Currently, the most popular officially recognized forms of health Qigong include Muscle-Tendon Change Classic (Yi Jin Jing), Five Animals (Wu Qi Xi), Six Healing Sounds (Liu Zi Jue), Eight Section Brocade (Baduanjin), Tai-Chi Health Qigong Cane, Twelve Section Brocade (Twelve Duanjin), Twelve Daoyin Sheng Yang, Mawangdui Daoyin, and Da Wu (11, 12).

When it was originally created, Tai-Chi was designed as a bare-handed soft martial art. Other Tai-Chi-based weapon forms (Tai-Chi Sword, Tai-Chi Fan, Tai-Chi Softball, and Tai-Chi Cane) have been developed since then. These new forms are based on the principles of Tai-Chi but aim to satisfy different needs. For example, these weapon forms of Tai-chi are beneficial for people who want to strengthen their upper extremities (grip strength, shoulder flexibility, and eye-hand coordination). Barehanded Tai-Chi is also called Tai-Chi Quan or Tai-Chi push hand. There are five major styles of Tai-Chi, each named after the Chinese family from which it originated: Chen-style (large, quick, powerful movements with deep stance), Yang-style (slow flowing, continuous, large movements with high stance), Sun-style (smooth, compact movements), and two Wu-styles (midpaced, compact movements with high stance).

How to Learn Health Qigong and Tai-Chi

Movements in health Qigong forms can be easily learned and practiced in a repetitive fashion, requiring little physical and cognitive effort (13). The practice of health Qigong emphasizes a slow and formalized routine, diaphragmatic breathing control, and a meditative state of mind, coordinated with musculoskeletal relaxation and symmetrical-balanced postures and movements. A combination of these elements aims to attain sufficient vital energy by cultivating well-balanced and fluid Qi flow. Health Qigong can be independently practiced by individuals through watching health Qigong videos. The common Qigong forms take about eight to 12 minutes to complete. Novice practitioners can start by trying to learning the physical movements of the forms. After practitioners learn the sequences of both isometric and isotonic segmental movements in upper and lower extremities, they can then incorporate breathing techniques and focus their mind to nourish Qi and guide the flow of Qi in their body. However, movements in Tai-Chi routines are highly choreographed, lengthy, and complicated. Therefore, the practice usually necessitates the supervision of experienced instructors. Health Qigong movements are frequently used as warm-up exercises for Tai-Chi routines because both Tai-Chi and health Qigong use the same basic TCM principles to regulate the body, breath, and mind.

How Health Qigong and Tai-Chi Work to Regulate Mood on the Basis of TCM Theories

According to TCM theories, a subtle energy, or Qi, exists in three main Dantian energy centers and circulate throughout the body by way of 12 main meridians or pathways. A free-flowing, well-balanced Qi system is believed to reflect good health, whereas psychosomatic illnesses are the result of Qi blockage in certain areas of the body. Health Qigong and Tai-Chi, as mind-body techniques, are believed to promote equilibrium of Qi and to alleviate Qi blockages, which may potentially prevent or delay the progression of diseases.

Many Western scientists challenge whether Qi exists. To address these queries, tools with the intent to measure Qi have recently been developed. An electrodermal device has been designed to measure skin electrical conductivity as a proxy index for Qi levels. It has been shown that the patterns of electrical conductivity correlate with the expected patterns of Qi (14). Compatible with TCM theories, studies have shown that electrical impedance levels are lower for many acupuncture points compared with the surrounding nonacupuncture skin areas, and conductance is higher between points on theoretical acupuncture energy channels than between points not on these channels (15, 16). In addition, practice of Qigong was shown to increase conductivity along acupuncture channels (14).

The Gas Discharge Visualization (GDV) device is another method of evaluating theoretical correlates of Qi. The GDV is used to photograph biophoton emission from the fingertips that purportedly measures the strength of each Qi channel in TCM theory. On the basis of the GDV measurement, a “balanced index” can be calculated that reflects whether the energy level in a specific organ energy channel is balanced (17). Larkey et al. (18) studied a group of patients with hypertension and reported that their balanced index improved after practicing a single session of Qigong. Similar results were found for both healthy participants and participants with chronic illnesses when they practiced Qigong, showing improvements in total density of emissions and balance across fingers (17, 19). Although both the electrodermal device and the GDV are exciting approaches, their reliability and validity in quantifying Qi remain to be verified.

Possible Mechanisms

The exact mechanisms of Tai-Chi and Qigong are unknown. Recent research studies have provided preliminary evidence on the physiological outcomes of meditation. On the basis of these findings, many researchers have proposed possible mechanisms on how meditation and meditative movements affect health outcomes. Admittedly speculative, we use these hypothesized mechanisms to formulate possible explanations on how Qigong and Tai-Chi produce their health effects.

Psychological Model of the Mechanisms of Mindfulness

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.

Attenuation of Stress Response

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.

Meditative Effects on the Brain

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).

Revitalizing Interoception

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).

The Effects of Breathing Exercises

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.

Effects on Epigenetics

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.

Clinical Evidence on Qigong and Tai-Chi for Anxiety and Mood Regulation

Meditative movements (such as Qigong or Tai-Chi) are widely practiced not only to improve general health but also to manage mood and improve psychological well-being. In recent years, people have increasingly been using Qigong and Tai-Chi as complementary and alternative therapies to manage psychological stress and mood. However, many of these studies recruited patients with chronic physical illnesses and healthy people, and only a few studies targeted patients with anxiety disorder or depression. A summary of these studies’ findings is presented next.

Clinical Evidence on Qigong

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).

Clinical Evidence on Tai-Chi

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).

Conclusion

Preliminary evidence suggests that Qigong and Tai-Chi may be potentially beneficial for management of depressive and anxiety symptoms in healthy adults and patients with chronic illnesses. Both Qigong and Tai-Chi are easily adaptable forms of mind-body exercises that can be practiced at any place or any time without special equipment. Thus, Qigong and Tai-Chi should be widely promoted for the improvement of emotional well-being. Given the limited numbers of RCTs and their methodological weakness, the results should be interpreted with caution. In the future, more rigorous studies with physiological evidence are warranted.