The Need for Evidence-Based Herbal and Nutritional Anxiety Treatments in Psychiatry




© Springer International Publishing Switzerland 2017
David Camfield, Erica McIntyre and Jerome Sarris (eds.)Evidence-Based Herbal and Nutritional Treatments for Anxiety in Psychiatric Disorders10.1007/978-3-319-42307-4_1


1. The Need for Evidence-Based Herbal and Nutritional Anxiety Treatments in Psychiatry



David A. Camfield1, 2  , Erica McIntyre3, 4 and Jerome Sarris5, 2


(1)
School of Psychology, University of Wollongong, Wollongong, NSW, Australia

(2)
Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, VIC, Australia

(3)
School of Psychology, Charles Sturt University, Bathurst, NSW, Australia

(4)
Australian Research Centre in Complementary and Integrative Medicine (ARCCIM), Faculty of Health, University of Technology, Ultimo, NSW, Australia

(5)
University of Melbourne, Department of Psychiatry, The Melbourne Clinic, The Professorial Unit, ARCADIA Mental Health Research Group, 2 Salisbury St, Richmond, Melbourne, VIC, 3121, Australia

 



 

David A. Camfield




1.1 The Experience of Anxiety


Anxiety is a ubiquitous part of the human condition, with anxiety disorders suffered by 14.4 % of Australians over a 12-month period [1], and 26.3 % over a lifetime [2]. Similar figures exist for the USA, with a life-time prevalence as high as 33.7 % [3]. Whilst fear is an emotional response to imminent threat, anxiety involves the anticipation of future threat [4] and may be experienced in response to a wide range of circumstances including public speaking, financial stress, separation, traumatic experiences, or substance use [5]. To the individual who is experiencing symptoms of anxiety, it is a distressing psychological state—and one that is associated with both apprehensive thoughts together with physiological symptoms including a pounding heart, difficulties in breathing, nausea and a feeling of detachment from the environment. Further, with chronic anxiety come additional problems such as restlessness, fatigue, difficulties with concentration and sleep, as well as muscular tension. Many individually additionally begin to adversely modify their lifestyles in order to avoid anxiety-provoking situations [6]. Although many individuals will experience transient anxiety as part of their day-to-day life, for other individuals, the symptoms become severe enough to cause significant impairment in day-to-day living. Current first-line treatments for anxiety include pharmaceuticals such as benzodiazepines and serotonin-reuptake inhibitors (SSRIs), as well as cognitive behavioural therapy (CBT) involving exposure to anxiety-provoking stimuli and the targeting of dysfunctional cognitions.


1.2 Limitations of Current Treatment Approaches


Whilst pharmaceutical treatments may be effective in bringing symptomatic relief to some patients, there are known issues which limit their efficacy. First, they do not always work well in conjunction with psychotherapeutic approaches, having been designed as standalone treatments rather than part of an integrative approach. For example, benzodiazepines may limit the efficacy of exposure therapy by blunting the experience of emotional arousal [7]. Antidepressants may also make it more difficult to access emotional states, with feelings of emotional numbness reported by 60 % of participants in a recent survey [8]. Second, many people do not respond to pharmaceutical treatments, with response rates to SSRIs reported at between 60 and 75 % [9]. Third, pharmaceutical treatments have a range of unacceptable side effects, including negative impacts on sexual functioning, appetite and sleep [1012], and discontinuing treatment can also lead to unwanted side effects and withdrawal symptoms that require careful management [9]. The question of dependency is also pertinent, particularly in the case of tranquilizers and benzodiazepines. But perhaps the greatest issue to contend with is that pharmaceutical treatments for anxiety are often not intended for chronic use, and have not been tested as such in regulatory trials. Whilst more favourable response rates have been shown for CBT in comparison to pharmaceutical anxiety treatments [1315], cognitive approaches also do not necessarily work for all individuals, particularly in cases where the patient is not ‘psychologically minded’.


1.3 Nutritional and Herbal Treatments for Anxiety


As conventional treatments for anxiety are not always effective or suitable for all individuals, it is important to consider other treatment options. As outlined in this book, an evidence-base is building for the efficacy of herbal and nutritional medicines in the treatment of anxiety. This evidence-base is particularly important considering the increasingly widespread use of these substances. For example, it has been estimated that around 34 % of the population in the USA are now using complementary medicines, and similarly 38.4 % of individuals in Australia [16, 17]. The contemporary use of herbal medicine differs significantly from traditional use, as nutraceuticals and herbal extracts are now predominantly commercialized products that are widely accessible [18], and these products are most frequently self-prescribed for anxiety symptoms, in addition to being prescribed by a range of health practitioners [19, 20]. An Australian study of general practitioners found that the majority of doctors did not have the confidence to discuss the use of complementary medicine with their patients as they believed that they lacked the knowledge needed [21]. Another US study found that as little as 20 % of general practitioners were comfortable discussing herbal medicines with their patients [22]. For these reasons, there is a need for greater access to reliable evidence-based information in regards to these substances, both for consumers and health practitioners.

Research conducted so far indicates that there may be some important advantages to the use of nutritional and herbal treatments in contrast to existing treatments. Whilst a majority of pharmaceuticals rely on a single active constituent to deliver therapeutic effects, nutritional substances and herbal extracts typically contain a vast array of psychoactive components [23]. In one regard, this may appear to be a problem for manufacturers wishing to provide a highly standardized treatment, and a simplistic solution may be to try and isolate single active components for extraction. However, any attempt to simplify the complex constellation of chemicals would neglect the fact that synergistic and polyvalent interaction between the components is a key aspect to their therapeutic advantage [24]. The interaction of the various plant components is something that has been well understood in traditional medicinal systems such as Ayurvedic medicine or Traditional Chinese Medicine (TCM) throughout the centuries [25]. Synergism refers to how the therapeutic effect is greater for a combination of substances than would have been expected from a consideration of individual contributions [23]. Polyvalence refers to the inclusion of substances that may not directly contribute to symptom relief, but influence the overall clinical efficacy of the substance; for example, through modification of important processes, including absorption, distribution, metabolism and excretion of bioactive constituents, or by aiding in the reduction of side effects [24]. Many of the natural substances described in this book are excellent examples of synergy and polyvalence; for example, Salvia spp., Valeriana officinalis and Hypericum perforatum.


1.4 Varied Mechanisms of Anxiolytic Actions


Herbal and nutritional treatments for anxiety may exert their effects according to both direct neurotransmitter effects and more chronic cellular effects. It is often the case that each treatment, particularly in the case of herbals, possesses multiple active constituents with sometimes differing and complementary modes of action. In regards to direct neurotransmitter effects, the gamma-aminobutyric acid (GABA) system is often implicated. GABA is the primary inhibitory neurotransmitter in the central nervous system, and also the target of benzodiazepines. Natural substances with known actions on the GABA system include Piper methysticum (kava), Passiflora incarnata (passionflower), Matricaria recutita (chamomile), Scutellaria lateriflora (skullcap) and Valeriana spp. (valerian); these are typically found to exert sedative as well as anxiolytic effects. Many natural substances have also been found to have effects on serotonin (5-hydroxytryptophan [5-HT]; the biogenic amine that is targeted by antidepressants and is implicated in the regulation of both mood, anxiety and obsessional thinking). Substances with serotonergic mechanisms of action include myo-inositol (MI), Hypericum perforatum (St John’s wort), S-adenosyl methionine (SAMe) and the traditional South American herbal combination Ayahuasca.

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Apr 12, 2018 | Posted by in PSYCHIATRY | Comments Off on The Need for Evidence-Based Herbal and Nutritional Anxiety Treatments in Psychiatry

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