y-aminobutyric acid (GABA) Neurotransmitter in Mental Health Disorders & Essential Oils
Danielle Daniel, PsyD Candidate, California Southern University
Psychopharmacology 87700, Alternative Method Concepts
January 21, 2013
Psychopharmacology defines the pharmaceutical drugs used to treat the psych or “mind” as it means in Greek. Pharmaco, in the word psychopharmacology, also comes from the Greek word pharmakon, which means “poison” or “drug”. New and developing research is showing evidenced based data of the psychoaromtic effects from the chemical constituents in essential oils. Essential oils are the complex chemical structures found in the aromatic compounds in plants. I have coined the term psychoaromacology to define this new emerging field. Psych meaning “mind” in Greek, aroma coming from the Latin root of aromaticos, and logy also from Greek meaning the “science of, knowledge of, or study of”. The field of psychoaromacology is a very promising science and holds a bright future for the treatment of mental health disorders. Essentialology is the study of these aromatic compounds in essential oils.
Psychopharmacology and the modern medical model have a very specific treatment theory. The theory follows the concept of discovering what the body “normally” does and then implementing a synthetic pharmaceutical drug to be within “normality”. The drug produces a chemical change in the body therefore requiring no lifestyle change by the individual. A simple example of this is the use of psychopharmacological drugs involved with the activity of serotonin, the neurotransmitter commonly found low in many psychiatric disorders, including patients with bi-polar and other depressive disorders. Selective serotonin reuptake inhibitors, SSRI’s, increase the serotonin activity in the brain by preventing the reuptake of serotonin from the synapses, therefore prolonging the effects of serotonin (Comer, 2010). This appears to be a great solution to a wide spread and increasing problem in depression and other clinical disorders thought to be low in serotonin, however, an alternative viewpoint will consider not only augmenting a synthetic manner of receiving serotonin, but why the serotonin is low or not being absorbed or circulated in the first place? Also it is important to look at how can you naturally produce or receive more serotonin. I would also pose another question offering an additional alternative view; is simply increasing serotonin the answer to treating these disorders? In his book, The Second Brain, Dr. Michael Greshon, the Chairman of the department of Anatomy and Cell Biology at Colombia University, explains that 95% of our serotonin is found in our intestines (Greshon 1999). This discovery proves the great connection that our brain chemistry and body have with one another and poses many alternative methods to simply treating disorders thought to be low in serotonin. Dr. Emil Kraeplin posited that the etiology of all psychiatric disorders reside in the physical realm and originate in biological and genetic malfunction (Smith 2012). So how can we naturally treat, produce, and restore brain chemistry?
In my research here, I have done a literature review on the chemical activity essential oils produce in the brain and in the body, therefore offering alternative methods of treatment for psychiatric disorders. First I will go into a basis of biological effects of essential oils, then I will discuss specific research for treatment of psychiatric disorders using essential oils.
Essential oils are concentrated natural chemical compounds found on plants. Plant essential oils are hetergeneuous mixtures of lipophilic volatile hydrocarbon monoterpenoids and sesquiterpenoids. They commonly consist in the hundreds of chemical constituents (Perry 2006) . The oil acts as antibacterial, antiviral, antifungal, an insecticide and also protects the plant against herbivores (Bakkali, Averbeck, Averbeck, & Idaomar, 2007). Whether the oils are inhaled or applied dermally, they enter the blood stream and produce measurable pharmacological effects. Aromatically, the oil passes through the olfactory neural pathway which allows both intraneuronal and extraneuronal access to the brain. Various research studies also have evidence that essential oils surpass the blood brain barrier influencing neurotransmitter activity (Perry 2006). Being oil based, essential oils are able to penetrate the cells bi-lipid layer which then can destroy the replication of viruses without damaging the membranes, proteins or the DNA. The cytoxicity of essential oils treat cells in the stationary phase of growth which make them highly antiseptic and antimicrobial (Bakkali, Averbeck, Averbeck, & Idaomar, 2007). “The cytotoxicproperty is of great importance in the applications of essential oils…Essential oils or some of their constiuents are indeed effective against a large variety of organisms including bacteria, fungi, protozoa, parasites, acarids, larvae, worms, insects, and molluscus” (Bakkali, Averbeck, Averbeck, & Idaomar, 2007 p.450). Because essential oils can interfere with the mitochondrial functions, it adds pro-oxidant effects to the body and therefore becomes an antitumoral agent (Bakkali, Averbeck, Averbeck, & Idaomar, 2007).
Certified Pure Therapeutic Grade
Before I elaborate further on the psychopharmacological effects of essential oils, the grade and quality of oil must be mentioned. Not every plant of the same species produces the same types or levels of chemical constiuents within it. Also not every oil bottle you may find for purchase is free of harmful chemicals. Therefore, in each research study, the chemical constituents of the oil are listed and it is highly recommend that before using oils for personal treatment, the quality and grade must be researched. For a quality oil, a company will do various chemical analysis on every liter of oil to ensure it is free of toxins, pesticides, synthetics or any other unknown or harmful substance. Second, via the chemcial analysis, a company will use the plants which contain the highest medicinal properties. For example, not every lemon tree produces the same amount of limonene, or not every thyme plant produces the same amount of thymol. The only grade of oil that ensures this high quality is called Certified Pure Therapeutic Grade.
Neurotransmitter y-aminobutyric acid (GABA)
To illustrate the importance of ensuring the quality and the medicinal constituents within the oil, one study reports the effects of s-limonene on brain neurotransmitters, and found that when exposed to stress, s-limone inhibited the HPA activity which in turn caused an anti-stress effect via the y-aminobutyric acid (GABA) receptor (Zhou et. al. 2009). GABA and its receptors are majorly distrubuted neurochemicals carrying inhibitor messages which cause a neuron to stop firing (Comer 2010). GABA regulates GABAergic neurons including the activity of 5-HTergic nuerons in the dorsal raphe nucleus which projects throughout the hypothalamus, hippocampus, and amygdala. This study orally administered s-limonene for 1 week to rats, and exposed them to stress via foot-shock, then studied the brain and found interesting results in the hypothalamus and amygdala regions. The results showed that glutamic acid (Glu) decreased significantly while the concentration of GABA increased, which seems to have acted as an inhibitor to the bodies stress chemical responses. The level of coricosterone, a stress hormone produced in the adrenal glands, was significantly higher in the control group than that of the group administered s-limonene, showing that the s-limonene attenuated the release of corticosterone (Zhou et. al. 2009).
The involvement of the GABA system as a whole has been strongly linked to several neuropsychiatric phenotypes, especially anxiety. The GABAa receptor is the site of action for anxiolytic drugs such as benzodiazepines and barbiturates. One study on mice found that reduced GABAa receptors resulted in increased fear and reactivity toward natural stimuli (Xuam et. al 2009). There are other neurotransmitters implicated in anxiety, however the theory, which continues to be supported by research involves a low concentration of GABA receptors or a malfunctioning of those receptors to capture the neurotransmitter data (Comer 2010). In Schizophrenia, there are several neurotransmitter and brain systems affected also, including the GABAergic system. Findings in the post-mortem tissue from patients with schizophrenia showed several changes in the GABAergic system (Damgaard et al 2011). “Roberts (1972) proposed the involvement of deficits in the y-amino butyric acid (GABAergic) transmitter system in schizophrenia” (Damgaard et. al. 2011, pg. 402). In one study, rats were treated with PCP, inducing a schizophrenic-like state of recognition and memory impairments, then they were administered a positive modulation of extra-synaptic GABA receptors. The results showed a reversing effect of the schizophrenic-like state with the administration of the GABA receptors (Damgaard et. al. 2011). There is significant evidence that GABA receptors are implicated in these disorders and the evidence shows that the essential oil constituent of s-limonene interacts therapeutically with the GABAergic system. Limonene is found high in citrus oils, especially lemon oil, and could provide natural chemical results in the body with the inclusion in a daily routine.
Another oil having positive interactions with the GABAergic system is lavender. I could not do a research paper on essential oils and mental health without mentioning lavender. Lavender has amazing aromatic and therapeutic qualities. It is widely known for its sedative andanxiolytic effects. There are many different species of lavender, however they do not all have the same phytochemistry and differ in the biological activities they produce. Lavendula angustifolia Mill. from France, is highest in linalyl acetate and linalool which show the greatest results for anxiolytic and sedative properties. Research has shown that inhalation of the essential oil of l. angustifolia produces sedativeeffects similar to those of the pharmaceutical drug diazepam, or brand name Valium. In one study, l.angustifolia blocked pentetrazol-, nicotine-, and electroshock-induced convulsions. The data suggested that the main constituents in l. angustifolia, linalool and linalyl acetate, cause clinical sedative effects via the modulation of the components of the glutamatergic system. The glutamatergic system is responsible for the excitatory neurotransmitter glutamate and serves as the precursor for the synthesis of the inhibitory GABA in GABAergic neurons (Perry & Perry 2006). L. angustifolia and diazepam cause the same neurochemical effects as this study has shown, however, diazepam has many undesired side effects that lavender does not. This offers a great solution again to excitatory states of anxiety disorders, schizophrenia disorders and even manic or hypo manic episodes. Another study on lavender, orally administered l. angustifolia to participants exposed to anxiety provoking films and conducted several electro-dermal responses to measure the effects. Those participants administered the lavender oil showed reduced anxiety responses via their heart rate, galvanic skin response, and heart rate variation measures in comparison to those of the control group who were administered a placebo (Bradley et. al. 2009). Lemon and lavender from these studies both have anxiolytic like properties within their phytochemistry, and interact differently with neurotransmitters. Both show promising results in reducing the body’s anxiety and stress responses and cause sedative effects. There are no known toxicity or side effects from using either oil if infact they are “pure” as they are naturally produced by the earth. There are many other essential oils that have been studied for their anxiolytic and sedative effects such as melissa, neroli, bergamot, roman-chamomile, marjoram, patchouli, rose, rosemary, and vetiver oil. This offers many solutions for the myriad of disorders that have excitatory states, including that of ADD and ADHD.
One last area I have researched is of interest to discuss. There is evidence that the inhalation of essential oils, increases neurogenesis in the adult mouse brain (Perry & Perry 2006). Neurogenesis is the process of generating new neurons in the brain, which normally occurs during fetal development. If new neurons are generated via essential oil inhalation, the brain has a greater possibility of healing from abnormal functioning. Schizophrenia for example has the largest reports of structural and functional abnormalities in the brain causing a myriad of implications in behavior and functioning. I have witnessed essential oils regenerating my skin tissue through the fading of 20 year old scars, and if they are powerful enough to regenerate the outer dermal layer, why not cerebral matter? If they are able to permeate the tiniest cell organelles within our cells to oxygenate and promote multi-cellular functions, why not inner brain cortices and functions? The answer is simple, they do.
Treatment of psychiatric disorders using essential oils is very promising and is free of adverse effects associated with conventional drugs. Psychoaromacology is a safer option than pharmaceutical drugs and along with Dr. Kreplin’s and Dr. Greshon theories, the psychiatric and biological worlds are interconnected therefore to affect a change in the mental environment, taking one pill and not changing a dietary lifestyle is not the answer. Nutrition and physical habits need to be examined and altered, and along with the use of essential oils, the human mind can have freedom from psychiatric imbalances. Essential oils hold the most promising alternative solution for psychiatric treatment and will become the future as the preferred method.
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Danielle Daniels is currently pursuing her PhD at California Southern University. Her doctoral specialization is in psychoaromacology. She is a full-time licensed clinician in Californa (LCSW) and has over 20 years experience with using essential oils.