Chinese herbal medicine for insomnia : evidence and experience

Insomnia, a condition with significant medical consequences, is becoming more and more prevalent worldwide. Hypnotic drugs are associated with dependence, adverse reactions and long-term risks. Psychotherapy is time- and resource-consuming and largely unavailable. As such, many people who present with insomnia also look for alternative treatments. Recent studies show that Chinese herbal medicine (CHM), a traditional herbal medicine based on holistic theories, could be a potential alternative. The aims of this doctoral research were to explore the potential benefits of CHM for the treatment of insomnia and provide guidance in the treatment of insomnia with CHM. For practical reasons, the empirical aspect of the investigation focuses on one specific CHM product, which is Zao Ren An Shen (ZRAS). The research questions include: (1) Is ZRAS a safe and effective treatment for insomnia disorder? (2) How do Chinese medicine clinicians diagnose and treat insomnia with CHM? This doctoral research consists of a narrative review and three major studies: one systematic review, one randomised, placebo-controlled trial and one clinical experience synthesis. In the systematic review, clinical trial that assessed the efficacy and/or safety of ZRAS for insomnia were systematically searched and screened. In the clinical trial, after one week of placebo run-in, 85 participants with insomnia disorder were randomly allocated to either take ZRAS capsule or placebo for four weeks. Insomnia severity, psychological status, fatigue levels, quality of life, subjective sleep parameters, objective sleep parameters, and adverse events were assessed through the intervention period and at a four-weeks follow-up. Both the investigator and the participants were blind to the treatment allocation. In the clinical experience synthesis (CES), clinical experience reports published in the literature, which described treatment of insomnia with CHM, were systematically reviewed and screened. The systematic review shows that ZRAS is safe and effective for insomnia. The randomised trial support ZRAS capsule as a safe and acceptable treatment, yet failed to improve significantly insomnia severity in insomnia patients. These differences may be explained by the poor quality of the studies included in the systematic review. The studies included in the systematic review and the randomised trial both used a standardised intervention approach. However, Chinese medicine clinician recommend an individualised approach, which may contribute to improved outcomes across a broader range of measures.