Complementary and alternative treatments for insomnia/insomnia -depression-anxiety symptom cluster: Meta-analysis of English and Chinese literature

This study systematically reviewed randomized controlled trials (RCT), published in English or Chinese, investigating the effect of complementary and alternative medicines (CAM) on significant insomnia/poor sleep quality and accompanying depression and/or anxiety symptoms. A meta-analysis was completed by calculating within-group effect size (ES) of each CAM treatment on sleep, depression and/or anxiety measures. Moderating analyses of study quality, language, treatment duration and presence of physical diseases were conducted to evaluate their impact on ESs. Between-group ES of CAM (vs. non-specific/placebo controls) were computed among high-quality studies. From an initial pool of 5047 articles, a total of 72 studies were included in the meta-analysis (44 in English; 28 in Chinese). All CAM modalities yielded significant, moderate to large effect sizes on sleep, depression, and anxiety symptoms yet with high heterogeneity. Significant between-group differences on sleep measures were found only between mindfulness-based treatment and non-specific/placebo controls. Chinese literature are associated with larger ESs. Future study should examine the presence and nature of the active components in different CAM approaches.