Tai chi and reduction of depressive symptoms for older adults: a meta-analysis of randomized trials.

The aim of the present article was to systematically review the effectiveness of tai chi for reducing depressive symptoms among older adults. Electronic databases were searched through January 2011. Reference lists of systematic reviews and identified studies from the search strategy were also screened. Randomized controlled trials of tai chi compared with waiting list controls in older adults with depressive symptoms measured by a self-report depression rating scale were included. Two authors independently identified eligible studies, extracted data and assessed the included studies for risk of bias. Estimates of depressive symptoms reduction used a random effects model, and the I(2) statistic was applied to examine heterogeneity. Four trials with a total of 253 participants met the inclusion criteria. Two studies were assessed as being of high quality; the remaining two studies were rated as moderate quality. All four studies compared tai chi with a waiting list control group. The pooled standard mean difference for these studies was -0.27 (95% CI -0.52 to -0.02, P=0.03). Tai chi appeared to have a significant impact on reducing depressive symptoms compared with the waiting list control groups. Further research is recommended with larger sample sizes, more clarity on trial design and the intervention, longer-term follow up, and concomitant economic evaluations.