Laurie Barclay, MD
Désirée Lie, MD, MSEd

May 27, 2010

Tai Chi appears to be associated with improvements in psychological well-being, although well-controlled, longer randomized trials are needed, according to the results of a systematic review and meta-analysis reported in the May 21 issue of BMC Complementary and Alternative Medicine.

"Tai Chi, the Chinese low impact mind-body exercise, has been practiced for centuries for health and fitness in the East and is currently gaining popularity in the West," said lead author Chenchen Wang, from Tufts Medical Center, Tufts University School of Medicine in Boston, Massachusetts, in a news release. "It is believed to improve mood and enhance overall psychological well being, but convincing evidence has so far been lacking."

The reviewers searched 8 English-language and 3 Chinese-language databases through March 2009 for randomized controlled trials, nonrandomized controlled studies, and observational studies reporting at least 1 psychological health outcome. Two reviewers extracted and verified data, and a random-effects model allowed meta-analysis of randomized trials in each subcategory of health outcomes.

Methodologic quality of each study was also evaluated.

The reviewers identified 40 studies enrolling a total of 3817 participants and reporting on a total of 29 psychological measurements. Of 33 randomized and nonrandomized trials, 21 reported significant improvements in psychological well-being with 1 hour to 1 year of regular Tai Chi. Specific effects in community-dwelling healthy participants and in patients with chronic conditions were decreased stress (effect size [ES], 0.66; 95% confidence interval [CI], 0.23 - 1.09), anxiety (ES, 0.66; 95% CI, 0.29 - 1.03), and depression (ES, 0.56; 95% CI, 0.31 - 0.80), and improved mood (ES, 0.45; 95% CI, 0.20 - 0.69).

"More detailed knowledge about the physiological and psychological effects of Tai Chi exercise may lead to new approaches to promote health, treat chronic medical conditions, better inform clinical decisions and further explicate the mechanisms of successful mind-body medicine," Dr. Wang said.

The beneficial association between Tai Chi practice and psychological health was supported by 7 observational studies with relatively large sample sizes.

"Tai Chi appears to be associated with improvements in psychological well-being including reduced stress, anxiety, depression and mood disturbance, and increased self-esteem. Definitive conclusions were limited due to variation in designs, comparisons, heterogeneous outcomes and inadequate controls. High-quality, well-controlled, longer randomized trials are needed to better inform clinical decisions."

The study authors have disclosed no relevant financial relationships.

BMC Complement Altern Med. 2010;10:23. Abstract

More information about the health effects of Tai Chi is available from the National Center for Complementary and Alternative Medicine

Clinical Context

Tai Chi is a form of low-impact mind-body exercise using balance, flexibility, and strength. Its use has spread worldwide for the past 2 decades, and it has been reported to have beneficial psychological effects in both healthy subjects and in those with medical conditions such as cardiovascular disease.

This is a systematic review and meta-analysis of studies on Tai Chi to determine its impact on psychological well-being.

Study Highlights

• The reviewers conducted an electronic search of the medical literature using 8 English-language and 3 Chinese-language databases through March 2009.
• They also searched reference lists of selected articles for studies.
• Included were original studies of randomized trials, nonrandomized comparison studies, and observational studies.
• Reviews, conference proceedings, and case reports were excluded.
• Studies were assessed for quality, and data were extracted for the meta-analysis by 2 reviewers.
• The reviewers determined ES for each outcome by pooling the ES of each study.
• An ES of 0 to 0.19 was considered negligible; 0.20 to 0.49, small; 0.50 to 0.79, moderate; and 0.80 and above, high.
• 2579 English-language and Chinese-language articles were reviewed and 40 identified for data abstraction.
• Studies had to include at least 10 human subjects and evaluate at least 1 outcome of psychological health including stress, anxiety, depression, mood, and self-esteem.
• Stress:
• For stress, there were 5 randomized trials, 5 nonrandomized trials, and 1 observational study from 4 countries (United States, Australia, Germany, and China) reporting effects on 870 participants aged 16 to 85 years.
• Subjective measures were used, such as the Perceived Mental Stress Score, the Impact of Event Scale, and the Chinese Psychological Stress Scores.
• There was a significant improvement in stress management and psychological distress (ES, 0.66 [moderate]).
• Tai Chi was associated with a benefit for stress in healthy adults, those with HIV-related distress, and elderly Chinese persons with cardiovascular disorders.
• The overall quality of the studies was modest to inadequate, with no controls in most studies.
• Anxiety:
• For anxiety, there were 5 randomized trials, 9 nonrandomized trials, and 5 observational studies examined in 1869 people from 4 countries (United States, United Kingdom, Australia, and China).
• Scales used included the Profile of Mood States Anxiety subscale; the Depression, Anxiety, Stress Subscale; and the Taylor Manifest Anxiety Scale.
• Tai Chi practiced 2 to 4 times a week (30 - 60 minutes at a time) for 5 to 24 weeks was associated with a significant reduction in anxiety (ES, 0.66 [moderate]).
• Overall study quality was modest.
• Depression:
• For depression, 10 randomized trials, 6 nonrandomized trials, and 4 observational studies examined effects on 2008 patients, with Tai Chi ranging from 1 hour to 14 years.
• Studies used the Center for Epidemiology Studies Depression Scale, Profile of Mood States Depression subscale, and the Beck Depression Inventory.
• Tai Chi for 6 to 48 weeks (40 minutes to 2 hours each, 1 - 4 times a week) resulted in reduced depression symptoms (ES, 0.56 [moderate]).
• However, most studies were on healthy populations, with only 2 studies on clinically depressed patients.
• Mood:
• For mood, 4 randomized trials, 8 nonrandomized trials, and 3 observational studies with 1613 patients examined Tai Chi offered from 1 hour to 14 years (1 - 7 times a week).
• The studies used various scales including the Profile of Mood States Scale, Functional Assessment of HIV Infection, and Symptom Checklist-90.
• Tai Chi significantly improved mood, with an overall ES of 0.45 (small).
• Tai Chi was of benefit for mood in healthy adults, elderly with cardiovascular disease risk factors, obese women, and adolescents with attention-deficit disorder.
• Study quality was poor overall, with inadequate controls.
• Self-esteem:
• Self-esteem was studied in 3 randomized trials and 1 nonrandomized trial in 425 subjects.
• Tai Chi practiced for 12 to 26 weeks (45 - 60 minutes, 2 - 3 times weekly) improved self-esteem, as assessed by scales such as Rosenberg's 10-item Global Self-Esteem Scale and the Body Cathexis Score.
• There was a positive association between Tai Chi and self-esteem, but an ES could not be calculated because quantitative results were limited.
• The authors concluded that the evidence supported a positive effect of Tai Chi on reducing stress, anxiety and depression symptoms, and enhancing mood and self-esteem, but study quality was limited and dose-response could not be assessed.

Clinical Implications

• Tai Chi is associated with reducing stress, anxiety, and depression symptoms and improving self-esteem and mood in a variety of patients.
• Quality of studies on the effects of Tai Chi is poor, and dose-response cannot be determined.