Role of Complementary and Alternative Medicines in Cognition and Anxiety

Cognition is a complex process that includes multiple domains, from learning and memory to attention. Dementia is the cognitive impairment by the loss of intellectual ability that hamper occupational functioning, social activities and relationships in the absence of loss of consciousness or with motor involvement [1]. It is estimated that the number of people living with dementia will almost double every 20 years to 42.3 million in 2020 and 81.1 million in 2040 [2]. Anxiety is described as “a psychological, physiological, and behavioral state induced in animals and humans by a threat to well-being or survival, either actual or potential” [3]. Globally as of 2010 approximately 273 million (4.5% of the population) had an anxiety disorder. It is more common in females (5.2%) than males (2.8%) [4].


Introduction
Cognition is a complex process that includes multiple domains, from learning and memory to attention. Dementia is the cognitive impairment by the loss of intellectual ability that hamper occupational functioning, social activities and relationships in the absence of loss of consciousness or with motor involvement [1].It is estimated that the number of people living with dementia will almost double every 20 years to 42.3 million in 2020 and 81.1 million in 2040 [2].Anxiety is described as "a psychological, physiological, and behavioral state induced in animals and humans by a threat to well-being or survival, either actual or potential" [3]. Globally as of 2010 approximately 273 million (4.5% of the population) had an anxiety disorder. It is more common in females (5.2%) than males (2.8%) [4].
Number of nootropics drugs has been developed for the treatment of cognitive deficits, from the FDA approved acetylcholinesterase inhibitors (e.g., Donepezil) and NMDA receptor antagonist e.g. Memantine,to those still under development ampakines, nicotinic receptor agonists, glycine inhibitors, and PDE inhibitors [5]. Benzodiazepine, selective serotonin reuptake inhibitor (SSRI), monoamine oxygenase inhibitors (MAOIs), tricyclic antidepressants (TCAs), tranquilizers such as buspirone, beta-blockers are the drugs that are indicated for anxiety disorder. Now a days herbal medicine and Complementary and Alternative Medicine (CAM) use is widespread in neurological disorders due to their natural origin and less side-effects. The World Health Organization (WHO) estimates that 80% of the population uses herbs; in the developing world rates could be as high as 95% [6]. Medhya Rasayanas are group of medicinal plants in Ayurveda (Indian system of medicine) to improve memory and intellect by Prabhava (specific action). MedhyaRasayanais a group of 4 medicinal plants that are Mandukaparni (Centellaasiatica Linn.), Yastimadhu(Glycirrhiza\glabra Linn.), Guduchi (Tinosporacordifolia and Shankhapushpi (Convolvulus pleuricaulis Chois), can be used singly or in combinations [7].In practice few more drugs are used as nootropic that are Aindri(Bacopa monniera), Jyothishmati (Celastruspanniculata), Kushmanda (Benincasahispida), Vacha (Acorus calamus) and Jatamamsi (Nardostachysjatamamsi) [7]. Convolvulus pluricaulis Chois. (Convolvulaceae), also known as Shankhpushpi, has been used traditionally for its memory enhancing, anticonvulsant, antianxiety, and sedative properties [8,9].

Open Access Journal of Neurology & Neurosurgery
Herbal plants such as passionflower, kava, St. John's wort and valerian root, as well as the amino acid lysine and the cation magnesium, have been used for centuries in Ayurveda and traditional medicine as antianxiety and to positively enhance mood [10].
The omega-3 polyunsaturated fatty acids (PUFA) also play an important role in cellular functioning (maintain optimal membrane fluidity) and normal brain cognitive function development including learning and memory [11]. The omega-3 PUFA incorporated into the neuron membrane also increase synaptic protein expression, strengthening the hippocampal synaptic plasticity [12].
Due to adverse effects and rising cost of the drugs that available presently, people are switching to complementary therapies which include nutritional supplements like omega-3 polyunsaturated fatty acids, herbal drugs and natural remedies for the management and treatment of psychological conditions. Cognitive enhancement is in demand, both in healthy populations and those with cognitive deficits. Currently drugs that are available have modest benefits. So much more evaluation has to be done because the aging segment of the population explodes over the upcoming decades, with increasing rates of cognitive decline and neurodegenerative disease. Also, we have to evaluate the combined effect of nutritional supplements with the herbal drugs combination to produce optimum desired effect with better compliance.