Cabral P, Meyer HB, Ames D. Effectiveness of yoga therapy as a complementary treatment for major psychiatric disorders: a meta-analysis. Prim Care Companion CNS Disord. 2011;13(4):PCC.10r01068. doi:10.4088/PCC.10r01068
Brinsley J, Schuch F, Lederman O, et al. Effects of yoga on depressive symptoms in people with mental disorders: a systematic review and meta-analysis. Br J Sports Med. 2021;55(17):992-1000. doi:10.1136/bjsports-2019-101242
Simon NM, Hofmann SG, Rosenfield D, et al. Efficacy of yoga vs cognitive behavioral therapy vs stress education for the treatment of generalized anxiety disorder: A randomized clinical trial. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2020.2496
Yoga is a form of mind-body fitness that involves a combination of muscular activity and an internally directed mindful focus on awareness of the self, the breath, and energy. Four basic principles underlie the teachings and practices of yoga's healing system. The first principle is the human body is a holistic entity comprised of various interrelated dimensions inseparable from one another and the health or illness of any one dimension affects the other dimensions. The second principle is individuals and their needs are unique and therefore must be approached in a way that acknowledges this individuality and their practice must be tailored accordingly. The third principle is yoga is self-empowering; the student is his or her own healer. Yoga engages the student in the healing process; by playing an active role in their journey toward health, the healing comes from within, instead of from an outside source and a greater sense of autonomy is achieved. The fourth principle is that the quality and state of an individuals mind is crucial to healing. When the individual has a positive mind-state healing happens more quickly, whereas if the mind-state is negative, healing may be prolonged.
The eight limbs are comprised of ethical principles for living a meaningful and purposeful life; serving as a prescription for moral and ethical conduct and self-discipline, they direct attention towards one's health while acknowledging the spiritual aspects of one's nature. Any of the eight limbs may be used separately, but within yoga philosophy the physical postures and breathing exercises prepare the mind and body for meditation and spiritual development.[4,10] Based on Patanjali's eight limbs, many different yogic disciplines have been developed. Each has its own technique for preventing and treating disease. In the Western world, the most common aspects of yoga practiced are the physical postures and breathing practices of Hatha yoga and meditation. Hatha yoga enhances the capacity of the physical body through the use of a series of body postures, movements (asanas), and breathing techniques (pranayama). The breathing techniques of Hatha yoga focus on conscious prolongation of inhalation, breath retention, and exhalation. It is through the unification of the physical body, breath, and concentration, while performing the postures and movements that blockages in the energy channels of the body are cleared and the body energy system becomes more balanced. Although numerous styles of Hatha yoga exist, the majority of studies included in this manuscript utilized the Iyengar style of yoga. The Iyengar method of Hatha yoga is based on the teachings of the yoga master B.K.S. Iyengar. Iyengar yoga places an emphasis on standing poses to develop strength, stability, stamina, concentration and body alignment. Props are utilized to facilitate learning and to adjust poses and instruction is given on how to use yoga to ease various ailments and stressors.
Yoga is recognized as a form of mind-body medicine that integrates an individual's physical, mental and spiritual components to improve aspects of health, particularly stress related illnesses. Evidence shows that stress contributes to the etiology of heart disease, cancer, and stroke as well as other chronic conditions and diseases. Due to the fact that stress is implicated in numerous diseases, it is a priority to include a focus on stress management and reduction of negative emotional states in order to reduce the burden of disease. Viewed as a holistic stress management technique, yoga is a form of CAM that produces a physiological sequence of events in the body reducing the stress response. The scientific study of yoga has increased substantially in recent years and many clinical trials have been designed to assess its therapeutic effects and benefits.
One of the main goals of yoga is to achieve tranquility of the mind and create a sense of well-being, feelings of relaxation, improved self-confidence, improved efficiency, increased attentiveness, lowered irritability, and an optimistic outlook on life. The practice of yoga generates balanced energy which is vital to the function of the immune system. Yoga leads to an inhibition of the posterior or sympathetic area of the hypothalamus. This inhibition optimizes the body's sympathetic responses to stressful stimuli and restores autonomic regulatory reflex mechanisms associated with stress. Yogic practices inhibit the areas responsible for fear, aggressiveness and rage, and stimulate the rewarding pleasure centers in the median forebrain and other areas leading to a state of bliss and pleasure. This inhibition results in lower anxiety, heart rate, respiratory rate, blood pressure, and cardiac output in students practicing yoga and meditation.[6,13,19,20]
Consistent yoga practice improves depression and can lead to significant increases in serotonin levels coupled with decreases in the levels of monamine oxidase, an enzyme that breaks down neurotransmitters and cortisol. A range of therapeutic approaches is available for the management of depressive disorders, but many patients turn to complementary therapies due to the adverse effects of medication, lack of response or simply preference for the complementary approach. A number of studies demonstrate the potential beneficial effects of yoga interventions on depression, stress, and anxiety.[18,21,22]
Yoga increases blood flow and levels of hemoglobin and red blood cells which allows for more oxygen to reach the body cells, enhancing their function. Yoga also thins the blood which can decrease the risk of heart attack and stroke, as they are often caused by blood clots. Twisting poses wring out venous blood from internal organs and allow oxygenated blood to flow in when the twist is released. Inverted poses encourage venous blood flow from the legs and pelvis back to the heart and then pumped through the lungs where it becomes freshly oxygenated. Many studies show yoga lowers the resting heart rate, increases endurance, and can improve the maximum uptake and utilization of oxygen during exercise.[13,20,26] Consistently getting the heart rate into aerobic range lowers the risk of heart attack. While not all yoga is aerobic, even yoga exercises that do not increase heart rate into the aerobic range can improve cardiovascular functioning.
While yoga is not a cure for a cancer, nor a definitive way of preventing it, yoga increases physical, emotional and spiritual wellness, and brings about a certain peace, of which many cancer patients desire. Yoga, breathing exercises, and meditation can reduce stress, promote healing, and enhance quality of life for patients with cancer.[28,29] The growth of tumors and other cancer indicators are exacerbated by stress, thus it is especially important for people with cancer to reduce and manage stress effectively. Several premises exist as rationale for applying yoga-based interventions with cancer patients. Research suggests that yoga can produce an invigorating effect on mental and physical energy that improves fitness and reduces fatigue. Additionally, when practicing yoga, a fundamental emphasis is placed on accepting one's moment-to-moment experiences creating mindfulness and not forcing the body past its comfortable limits. Having this healthy sense of acceptance is especially important for individuals dealing with life-threatening illness as it decreases the stress one experiences from unpleasant symptomology. Initially, cancer patients likely benefit from the poses themselves which are designed to exercise each and every muscle, nerve and gland throughout the body. The postures precisely address the tension, holding, and blockage of energy in any particular joint or organ. As this tension is released, energy flows more readily throughout the body and allows patients to experience a sense of increased well-being and strength as well as a balance of mind, body and spirit.
While stimulation is good, too much taxes the nervous system and yoga provides relief from excess stimulation and the stressors and hectic nature of modern life. Restorative postures, savasana, pranayama, and meditation encourage pratyahara, a turning inward of the senses which enables downtime for the nervous system, the byproduct often being improved sleep. Pharmacological treatment of insomnia is often associated with hazardous side effects such as states of confusion, psychomotor performance deficits, nocturnal falls, dysphoric mood, impaired intellectual functioning and daytime sleepiness, especially in older adults. Therefore, alternative forms of therapy for improving sleep are becoming utilized more frequently. These alternative therapeutic approaches can be generally classified into three categories: behavioral based educative methods (e.g. avoiding caffeine or other stimulants before bedtime), relaxation techniques (e.g. progressive muscular relaxation, yoga, and meditation) and formal psychotherapy. Because of its ability to increase relaxation and induce a balanced mental state, yoga has been studied to evaluate its possible effects on sleep and insomnia.[16,30]
In summary, stress has a negative impact on the immune system and prolonged exposure increases susceptibility to disease and leads to physical and mental health problems such as anxiety and depression.[9,19] Practicing yoga and meditation as a means to manage and relieve both acute and chronic stress helps individuals overcome other co-morbidities associated with diseases and leads to increased quality of life.[14,31] As a non-pharmacological form of treatment, yoga based interventions are an alternative option for the treatment of mood disorders. Further investigation of yoga as a therapeutic intervention in depressive disorders is needed and future studies should seek to identify which of the yoga-based interventions is most effective and what levels of severity of depression are more likely to respond to this approach. 2b1af7f3a8