Anxiety is a is a mental disorder affecting several million people, worldwide, and such a condition is characteristically difficult to diagnose and treat due to the inherent complexity of the central nervous system.
To date, the most prevalent intervention uses anti-depressants/serotonin-specific reuptake inhibitors/benzodiazepines though such pharmacological approaches are often ineffective and replete with unwanted side-effects.1(2)
Thus, there exists a growing interest in alternative therapeutic approaches that circumvent side-effects common to drugs for anxiety. As such, the following will consider botanicals as a viable alternative to the aforementioned compounds and their anxiolytic effects.
Anxiety can be defined as feelings of persistent worry that interferes with an individual’s ability to achieve and maintain relaxation.1(2) Anxiety can manifest into several forms to include social phobia, panic disorder, obsessive compulsive disorder, and generalized anxiety disorder.1(2)
Such permutations of anxiety not only produce unappealing feelings; anxiety can produce headaches, aches, muscle tension, sweating, and uncontrolled trembling in addition to potentiating the risk of cardiovascular disease and cerebrovascular disease.1(2)
The underlying causes of anxiety are vast to include health related stress (i.e., individuals worried about contracting COVID-19), economic-related anxiety (i.e., businesses shutting down), anxiety related to changes in daily routine, and anxiety induced from isolation (i.e., social distancing).2
Considering there is a lifetime prevalence of anxiety disorders reaching 16.6%, globally, an emerging need to find safe and effective strategies to manage the same has taken place. As such, the following will consider botanicals as a potentially viable alternative to traditional pharmaceutical interventions.
Lakhan et al1(2) stated that botanicals have been used to treat anxiety for centuries in traditional medicine, though research confirming its true efficacy and mechanisms have taken place only in the last 10-15 years. Although botanical research is largely in its infancy stages, several reviews of clinical effectiveness have been published within the last ten years indicating potential beneficial uses.
Such botanicals which have been explored include Magnolia, Phellondendron, ginkgo biloba, black cohosh, lemon balm, hops, skullcap, passionflower, lavender, valerian, and St. John’s wart.1(2) However, before the research efforts of Lakhan et al,1(2) no systematic reviews of the same was implemented.
Thus, said researchers narrowed their research to supplements and herbs that served as anxiolytic agents quantified through rating scales and/or self-reports.1(2) Furthermore, studies had to be considering human subjects, studies had to be published in English, the botanicals under review had to be the entire plant extract, with sample sizes greater than 10 participants. The following will consider the researchers’ findings in greater detail.
After research parameters (inclusion/exclusion criteria) were applied by Lakhan et al,1(7) 24 studies (a total of 2619 participants) remained for the systematic review, which included St. John’s wart, kava, passionflower, as well as magnesium and lysine.
Passionflower, also known as Passiflora incarnata, has long been used as an anxiolytic and listed as an official plant drug by the institutions of India, Egypt, Switzerland, France, Germany, Britain, and America.1(8) Although the anxiety-reducing effects of passionflower have been well documented, greater difficulty has been experienced elucidating which constituents of the flower produce the same since thousands of phytochemicals reside in said flower.1(8)
Despite such limitations, Lakhan et al1(8) cited one double-blind, placebo-controlled study whereby one conventional pharmaceutical drug (benzodiazepine) was compared to passionflower; no differences (in terms of efficacy) were found between the two groups, and the passionflower group experienced less side effects. Though research was preliminary, findings suggest the potential of passionflower as an alternative.
Kava, also known as Piper methysticum, is a plant consumed in the form of a drink that has been consumed by many cultures to relieve insomnia, restlessness, and anxiety.1(9) Of particular note is kava tends to maintain mental alertness, where benzodiazepines do not.
Furthermore, kava is thought to exert its effects by binding to GABA receptors (type A), as well as blocking calcium channels and reuptake of such substances like norepinephrine and dopamine, helping produce relaxation.1(9) One randomized, double-blind, placebo-controlled study examined 101 participants with anxiety symptoms whereby kava, and a placebo, was used over a 25-week trial period.
Interestingly, the kava group showed improvements in primary anxiety (mentioned previously) and secondary anxiety (anxiety from another source such as losing one’s job).1(9) Five other randomized controlled trials also confirmed said results and suggested kava could be a viable monotherapy for generalized anxiety and anxiety disorder.1(9)
St. John’s wart (SJW), alternatively known as Hypericum perforatum, has been used for centuries in traditional medicine, and has been licensed in Germany to treat sleep disorders, anxiety, and depression.1(9)
The researchers cited a meta-analysis which indicated that SJW was more effective than a placebo in treating mild/moderate depression, and was also as effective as imipramine (anti-depressant) in treating the same.1(10) However, other studies reviewed by Lakhan et al1(10) indicated that few studies considered the effectiveness of SJW in treating anxiety specifically.
Of the 4 randomized controlled studies reviewed, the results elucidated from the research were contradictory in nature; some studies suggested SJW reduced anxiety, but said studies also incorporated valerian root.1(11) Furthermore, other doses in the study increased the concentration of valerian, which further decreased anxiety, suggesting valerian may have had a stronger effect on said outcomes than SJW.1(11)
In conclusion, anxiety is a is a mental disorder effecting several million people, worldwide, and is characteristically difficult to diagnose and treat due to the inherent complexity of the central nervous system. To date, the most prevalent interventions incorporate anti-depressants/serotonin-specific reuptake inhibitors and benzodiazepines though such pharmacological approaches are often ineffective and replete with side-effects.
However, research suggests that certain botanicals, especially kava/passionflower and possibly SJW, could serve as viable adjuncts and possible alternatives to traditionally used synthetic compounds. Such a botanical-centered approach could help liberate individuals from anxiety, while reducing side effects often associated with their pharmaceutical counterparts.
References
1. Lakhan SE, Vieira KF. Nutritional and herbal supplements for anxiety and anxiety-related disorders: Systematic review. Nutr J. 2010;9(42):1-14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2959081/. Accessed June 16, 2020.
2. Bareket-Bojemel L, Shahar G, Margalit M. COVID-19-related economic anxiety is as high as health anxiety: Findings from the USA, the UK, and Israel. Int J Cogn Ther. 2020. doi: 10.1007/s41811-020-00078-3.
-Michael McIsaac