A systematic review of insomnia and complementary medicine

Abstract

In concert with growing public interest in complementary and alternative medicine (CAM), these therapies and products have been increasingly studied over the past two decades for the treatment of sleep disorders. While systematic reviews have been conducted on acupuncture and valerian in the treatment of insomnia, to date no comprehensive review has been conducted on all major CAM treatments. We sought to address this via a rigorous systematic review of hypnotic CAM interventions, including herbal and nutritional medicine, acupuncture, acupressure, yoga, tai chi, massage, aromatherapy and homoeopathy. The electronic databases MEDLINE (PubMed), CINAHL, PsycINFO, and The Cochrane Library were accessed during late 2009 for CAM randomized controlled trials (RCTs) in the treatment of chronic insomnia. Sixty-four RCTs were identified, of which 20 studies involving eight CAM interventions met final inclusion criteria. Effect size calculations (where possible) and a quality control analysis using a modified Jadad scale were undertaken. Many RCTs lacked methodological rigor, and were commonly excluded due to small sample size or an inadequate control condition. Among the studies that met inclusion criteria, there was evidentiary support in the treatment of chronic insomnia for acupressure (d=1.42-2.12), tai chi (d=0.22-2.15), yoga (d=0.66-1.20), mixed evidence for acupuncture and L-tryptophan, and weak and unsupportive evidence for herbal medicines such as valerian. Surprisingly, studies involving several mainstream CAM therapies (e.g., homoeopathy, massage, or aromatherapy) were not located or did not meet basic inclusion criteria. If CAM interventions are to be considered as viable stand-alone or adjuvant treatments for sleep disorders, future researchers are urged to use acceptable methodology, including appropriate sample sizes and adequate controls. RCTs evaluating other untested CAM therapies such as massage, homoeopathy, or osteopathy are encouraged, as is the exploration of using CAM therapies adjuvantly with conventional therapies.