by Madeline Abramson
art by Caitlin O’Neil
Do You Mean Yoga Could Treat My Depression?
In 10th grade, after living with depression for several years, I arrived at an appointment with my latest mental health practitioner. Hoping for a fresh perspective that would finally improve my life, I divulged my worries, detailed my cynicism, and described my symptoms to a woman I had met all but ten minutes before. She gave away little with her expression. She stared at me blank-faced until I finished sharing my story, only for her to utter the short but sweet sentence, “You should try yoga.” Déjà vu struck. No, no, no, this was not a fresh perspective! This was the same advice my previous doctor, my mother, heck, even my gym teacher had recommended! I wanted treatment, therapy, or something other than physical exercise to help quiet the negative thoughts constantly circling my mind. Was yoga truly the answer? Yoga has come onto the radar of modern biomedical practice for its ability to ease symptoms of various neuropsychiatric illnesses and various diseases of the brain [1]. But does yoga’s relationship to the wellness movement prevent us from exploring yoga as a practice of expanding the mind and body, improving mental health, and mitigating symptoms of various neurological illnesses? I once would have written off yoga as a treatment, but now, an overwhelming body of evidence suggests that my 10th-grade doctor may have been right.
The History of Yoga
Given the current perceptions around yoga in the United States as a form of physical exercise, we often neglect to understand the roots and enormity that is this several-thousand-year-old practice. Yoga comes from the Sanskrit word “yuj,” meaning “to yoke” or “join,” referring in some contexts to the expansion of the self to become “joined” with the universe [2, 3]. The yogic system seeks to achieve harmony between one’s physical body, mind, and nature [2]. According to yogic lore, yoga began at the dawn of civilization from the teachings of Shiva, also known as Adiyogi, who was the first spiritual teacher, or guru, of yoga. Adiyogi’s knowledge spread worldwide, but the practice was most significantly taken up in the Indian subcontinent and developed through Indian folk traditions [2]. The first textual evidence of yoga practice appears in the Upaniṣads, Vedic texts estimated to have been written between 700 to 500 BCE that laid the groundwork for later Hindu philosophy, as a skill for the “inner” and “outer” ascent of one’s consciousness into space [3]. In the Kaṭha Upaniṣad, the God of Death reveals yoga as a means to leave behind joy and sorrow, overcoming death itself in the process [3]. Patanjali, an ancient sage, was the first to compile the Yoga Sutras, the Sanskrit literature that defined the first systems of yoga [4]. He described an eight-limbed path to escape the cycle of suffering and rebirth in order to achieve enlightenment: yama (the way we treat others), niyama (self-discipline), āsana (posture), prāṇāyāma (breath control), pratyāhāra (turning senses inward), dhāraṇā (focused attention), dhyāna (meditation), and samādhi (enlightenment) [4].
Today, 16 million people practice yoga in the United States [3]. Hatha yoga, which focuses primarily on āsana (posture) and some aspects of prāṇāyāma (breathing techniques), is the prevailing style of yoga practiced in America [3]. You may recognize some āsanas (postures), like Adho Mukha Shvanasana (downward-facing dog) or Vrikshasana (tree pose). So, given all of this history, what does yoga have to do with neuroscience? Believe it or not, recent research has shown that yoga may present an innovative approach to bridging the gap in treatment for diseases that affect the brain, such as major depressive disorder (MDD) [5–9], schizophrenia [10–12], and multiple sclerosis (MS) [13–15].
Yoga and Major Depressive Disorder
Before we can jump into the benefits of yoga on neuropsychiatric and neurodegenerative illnesses, we must first come to understand the illnesses themselves. MDD is a mental illness characterized by episodes of at least two weeks marked by changes in mood, affect (emotional expression), and cognition, with feelings of sadness,
hopelessness, emptiness, as well as fatigue and lethargy [16]. It is estimated that 3.4 percent of the global population lives with disorders relating to depression [17]. The current treatment model for MDD tends to involve a trial-and-error sampling of different antidepressant medications; however, many antidepressants have adverse side effects or do not completely ameliorate symptoms [18]. These issues concerning the ineffectiveness of treatments for MDD open the door for non-traditional treatment methods to be explored, such as yoga, with many studies demonstrating its efficacy in easing symptoms.
Though yoga is not necessarily a replacement for conventional pharmacological treatments, it has been shown to have an additive effect on helping improve MDD symptoms [5, 6, 19]. For instance, Tolahunase et al. [5] examined āsana (postures), prāṇāyāma (breathing techniques), and dhyāna (meditation) as potential additive treatments for MDD. The study found a significant decrease in the severity of MDD as measured by a standardized clinical measurement called the Beck Depression Inventory-II, which is a self-report measure that asks patients to choose statements that best describe their thoughts and feelings related to depressive symptoms, such as sadness, loss of appetite, hopelessness, and self-blame [5, 19]. These results were replicated in another study using similar methods to examine changes in symptoms of depression in women diagnosed with MDD following a mindfulness-based yoga practice [6]. This second study found a significant reduction in the severity of depressive symptoms, especially decreases in the behavior of negatively fixating on past events, also known as rumination [6].
Other studies examining yoga as a treatment for depression have measured hormonal changes related to stress in depressed patients [7, 8, 20]. For instance, the stress hormone cortisol is seen at higher levels in some patients with MDD, and this is thought to be caused by the body’s overactivity in response to stress [7, 20]. In one study, cortisol levels were measured in patients on antidepressants only, yoga only, or a combination of yoga and antidepressants [7]. While all three groups saw reductions in cortisol, the most significant decreases in cortisol levels occurred in the groups doing yoga alone or yoga and medication [7]. These studies provide a glimpse into the possibilities of yoga as a treatment for MDD in addition to traditional pharmacological intervention, and their results have been replicated [8].
Yoga and the Schizophrenia Spectrum
Yoga has also been implicated in alleviating symptoms of schizophrenia or other aspects of schizophrenic-like disorders [10, 11, 21, 22]. The schizophrenia spectrum is a variety of disorders typically defined by the presence of “positive” symptoms like delusions, hallucinations, disorganized thinking or speech, and disorganized or abnormal motor behavior [16]. Schizophrenia is also characterized by “negative” symptoms, such as diminished emotional expression, lack of pleasure, and lack of motivation [16]. The cause of schizophrenia is currently unknown, but potentially results from a combination of one’s genetics and environment [23]. However, there appear to be stable changes in the increases of pro-inflammatory proteins and decreases in brain matter volume in people with schizophrenia [24, 25]. Antipsychotics, the standard treatment for disorders on the schizophrenia spectrum, have often proven ineffective in treating the negative symptoms and changes in social cognition seen in schizophrenia [26]. Many patients with schizophrenia exhibit alterations in social cognition, such as the inability to recognize others’ emotions and practice empathy, which contributes to difficulty with social and occupational life, even when stabilized on antipsychotics [10, 25].
Studies assessing the efficacy of yoga alongside antipsychotics for schizophrenia have shown optimistic results [10, 21, 27]. Social cognition problems in schizophrenia may arise from low levels of oxytocin, a hormone responsible for creating trust and connections with others [21, 22]. In one experiment, researchers examined how oxytocin levels changed in antipsychotic-stabilized patients with schizophrenia when introducing yoga into their lifestyles [10]. They also assessed whether yoga could improve positive (hallucinatory) symptoms, negative (decreased emotion) symptoms, and social cognition. The study found that both the yoga and non-yoga groups showed improvements regarding these positive and negative symptoms. However, the yoga group exhibited far more significant improvements in social cognition, most likely connected to the increases in oxytocin levels that were also seen [10].
Postural stability is also an issue in schizophrenic patients and increases the risk of falls, potentially as a side effect of medications or as a symptom of schizophrenia itself [27]. In a study examining the impact of yoga on postural stability in patients with illnesses on the schizophrenia spectrum, researchers saw that āsana (postures), prāṇāyāma (breathing techniques), and deep relaxation decreased postural imbalance, as well as increased body flexibility and reduced risk of falls [11]. As a result of the limited understanding of what causes schizophrenia, it is difficult to pinpoint the neuroscientific mechanisms through which yoga is able to relieve symptoms. While schizophrenia may not be directly improved by yoga, there is a clear link to the decrease in symptom presentation.
Yoga and Multiple Sclerosis
Multiple sclerosis (MS) is a chronic neurodegenerative disorder characterized by one’s immune system attacking itself and degrading myelin in the brain [28]. Myelin is essential for neuronal insulation, meaning that it helps neurons communicate faster and more effectively—the damage of myelin, therefore, can lead to several problems relating to neural connectivity [28]. About 0.15 percent of the US population lives with MS [29], and their lives are severely affected by symptoms such as muscle spasticity and weakness, problems with walking, chronic pain, fatigue, sleep disturbances, and abnormal bladder function [30]. Current treatments for MS involve suppressing the immune system to prevent further lesions (the areas of the brain with degraded myelin). However, little treatment is available for the slow development of symptoms and disabilities resulting from active lesions or lesions that have been partially re-myelinated [28].
Yoga as an additive treatment has been suggested to alleviate some MS symptoms and increase quality of life [13–15]. For instance, in a clinical trial conducted with 60 women with MS, subjective pain levels and overall quality of life were examined [13]. Those who practiced yoga, focusing on āsanas (postures), prāṇāyāma (breathing techniques), and dhāraṇā (focused attention), experienced decreases in subjective pain levels and increases in quality of life [13]. Cognitive impairment is also a common symptom in patients with MS [14]. In one study examining how MS patients’ cognitive function could be improved by yoga-based relaxation techniques, it was found that these patients' information processing speed and executive function were enhanced with exposure to yoga [14].
Furthermore, many physical symptoms of MS have shown to be alleviated by yoga. Some of the more bodily elements of yoga, like āsana (postures), can be helpful for regaining muscle strength. Studies have shown that yoga interventions can have direct effects on the improvement of muscle strength [31]. In terms of yoga’s relief of other physical symptoms of MS, Patil et al. [15] saw improvements in bladder function as well.
While yoga has been shown to improve symptoms of MS, studies have shown that yoga can also improve the quality of life for patients with other neurodegenerative diseases as well [4, 32]. For instance, a 2015 study by Colgrove et al. [33] examining yoga’s effects on patients with Parkinson’s disease saw decreases in physical symptoms and increases in quality of life. There are still many more unanswered questions regarding yoga’s efficacy in treating MS, like whether prāṇāyāma (breath control) or āsana (postures) are more beneficial depending on the physical versus cognitive symptoms, but one thing is for sure: yoga is more than just a hobby or system of conducting oneself. It is truly an effective treatment option with the potential to change lives for those with neurodegenerative and psychiatric illnesses.
Molecular Mechanisms
Yoga's effects begin at the molecular level. Yoga has been shown to change levels of the signaling molecules that neurons release to communicate with other neurons and cells, known as neurotransmitters [34, 35]. Research suggests that levels of the neurotransmitter γ-Aminobutyric acid (GABA), which inhibits communication between neurons, increase with the practice of yoga [35]. Low GABA levels have been correlated with depression and anxiety [36]. Therefore, the increase in GABA due to yoga may mitigate depression and anxiety symptoms. Other neurotransmitters affected by yoga are those connected to pleasure, such as dopamine, and those responsible for the modulation of mood, learning, and memory, such as serotonin. Like GABA, yoga practice has been shown to increase serotonin and dopamine levels, both of which are involved in the chemical imbalances associated with neuropsychiatric conditions such as schizophrenia and depressive disorders [34].
Yoga has also been shown to cause significant changes in measurements taken in the body related to inflammation and disease, known as biomarkers. For instance, one yoga study detected an increase in a biomarker called brain-derived neurotrophic factor (BDNF) [5]. BDNF is a protein that promotes the survival, maintenance, and development of new neurons, a process known as neuroplasticity [5]. Interestingly enough, yoga’s ability to increase neuroplasticity via the BDNF protein has a similar effect to that which classical antidepressants seek to achieve [37]. Reductions in pro-inflammatory compounds were also observed, specifically with oxygen-reactive species, which are linked to degeneration in the brain [5]. This reduction in pro-inflammatory compounds may contribute to the decreases in the degeneration of brain tissue responsible for structural changes associated with neurodegenerative diseases, depression, and schizophrenia [12, 28, 38].
Structural Brain Changes
The molecular changes caused by yoga can promote structural changes in the brain, many of which can lead to a decrease in symptom presentation [39, 40]. Researchers have noted that chronic stress and psychiatric illnesses decrease the volume of the brain region responsible for learning and memory, known as the hippocampus [38]. This decrease in brain volume may be attributed to inflammation of brain tissue, potentially via an inflammatory molecule called interleukin-6 [39]. Yoga has been shown to decrease levels of interleukin-6 in the body [39]. Such an effect may indicate that mindfulness practices can increase the volume of the hippocampus, as well as other areas of the brain responsible for emotion regulation, processing information related to the self, and positioning oneself in relation to the world around you [41, 42]. Increases in these areas of the brain are incredibly relevant to neuropsychiatric illnesses like schizophrenia, in which there are deficits in processes regarding awareness of the self and others [25]. Another study confirmed that long-term meditation, or dhyāna, is linked to increases in brain matter density and volume in the medulla oblongata, the area of the brain responsible for maintaining the body’s autonomic functions like breathing, blood pressure, heart rate, and relaying sensory inputs [40]. This finding suggests that those who meditate may see more significant control of respiration and heart rate [40, 43].
Limitations on Studies of Yoga
This article presents just a few examples of how people with neuropsychiatric and neurodegenerative diseases can see some symptom improvement with the incorporation of yoga into their lifestyles. However, while the benefits of yoga seem impressive, the takeaway of this article should not be that yoga alone is a sufficient treatment. Antidepressants, antipsychotics, and immune suppressors, respectively, are still the standard treatments for depression, schizophrenia, and multiple sclerosis. It would be unsafe and unethical to remove patients from these medications to examine the efficacy of yoga alone as a treatment, therefore making it difficult to study yoga as an isolated treatment.
There are also several limitations to studies aiming to prove that yoga is an effective additive treatment. While many of these studies use patients already stabilized on medication, the researchers cannot control for the type of medication, so it is possible that some of the changes in symptoms could be attributed to those different treatments. A future study may wish to examine how patients stabilized on the same medication respond to additive yoga therapy. Many studies have also failed to investigate all aspects of the yogic system as methods of treatment, most of them opting for some combination of just āsana (posture), prāṇāyāma (breath control), or dhyāna (meditation), or simply referring to them as “yoga-based relaxation techniques [5, 6, 10, 11, 14, 15, 31]. It would be interesting to see if any one of the eight limbs of yoga is more productive than the others at generating positive changes to the brain, or if the integration of all eight limbs of yoga would be the most effective. The research discussed also used short-term yoga interventions to examine the efficacy of yoga on symptoms, but many of the studies did not follow up to explore the long-term benefits of consistent yoga practice [5–15]. In the study on postural instability of patients with schizophrenia-related disorders, for instance, the researchers saw that eight weeks after the yoga treatment, the positive effects of yoga were no longer present [11]. It may be that long-term, sustained yoga practice is necessary to continue alleviating symptoms. In addition, many articles examining MS primarily used female patients, which could be attributed to the fact that MS is more prevalent in females than males [28, 44]. Still, it may be beneficial to see if the positive effects of yoga are found equally between males and females with MS.
In most scientific research, it is very difficult to account for and control all variables related to a study. In the next several years, if we wish to confirm some of the fascinating findings relating to yoga as a neuropsychiatric treatment, there need to be more studies that guide us through the mechanisms in which yoga is able to alleviate symptoms of neuropsychiatric and neurodegenerative disease. However, this area of research is still a developing field that has many opportunities to provide more conclusive evidence.
Yoga and the Wellness Movement
While practicing yoga may have immense physiological benefits, several aspects of yoga subculture must not go unspoken. For one, it is crucial to understand that yoga has a rich and deep history in India, particularly within Hinduism, Jainism, Buddhism, and Taoism [3]. However, many who practice yoga today fail to recognize the practice’s history and cultural grounding. As a result, yoga has become culturally appropriated, co-opted, and commercialized for capitalistic gain. Many people fail to recognize the diversity of what yoga as a spiritual practice can look like. Yoga is not simply people in yoga studios wearing yoga pants with palms pressed together. This is a cherry-picked vision of yoga that fails to interpret yoga as a way to conduct oneself with respect to the mind, body, and world around you, instead focusing on it as solely a form of exercise [45].
The move away from understanding yoga as a mechanism for harmonizing one’s relationship with themselves and the environment is deeply rooted in yoga’s adoption into the wellness movement. The wellness movement saw its origins in privileged Europeans in the late 19th century looking to bolster their physical well-being [46]. While wellness culture began with the intention of regaining autonomy of physical, emotional, and spiritual well-being, it has since become a practice targeted toward affluent members of society who can afford to implement a rigorous regimen of health into their lifestyles. Yoga, exercise, “health conscious” foods, diet culture, supplements, and “self-care” are all packaged as part of the wellness culture system. But as a whole, wellness culture fails to acknowledge their exclusion of anyone who is not white or affluent.
As a white woman myself, I understand that the yoga space in the United States welcomes my identity. Still, as a writer in an article about yoga, I cannot fail to recognize that my identity is situated amongst an oppressive culture that has appropriated yoga for its own commercial and perhaps subliminally racist gains. Many black yoga practitioners report being faced with tokenization, which is the superficial attempt to include underrepresented groups to give the appearance of diversity, and overt racism in the yoga community [47]. Taking a yoga class itself is a luxury afforded only to those who have the disposable income to spend $75 a month or so on yoga classes, depending on the studio. Despite being a practice anyone can undertake, one must acknowledge that the space for yoga in the United States is steeped in financial inaccessibility, racism, and cultural appropriation.
How You Can Respectfully Incorporate Yoga Into Your Own Life
Before scientific studies began to examine the effects of yoga on health, ancient yoga practitioners were aware of yoga’s powerful capability to expand the mind and body. And while the Americanized norms of yoga presented by wellness and popular culture are not necessarily accurate, there are many ways to incorporate yoga into your own practice, especially given the wide-spanning nature of yoga and the scientific evidence that backs its health benefits. You can try yoga by practicing mindfulness—journaling and taking the time to look inward and accepting yourself. You can practice yama (the way we treat others) by taking the time to understand those around you and how you treat them, especially by practicing empathy. Meditation does not necessarily have to include sitting cross-legged with the hopes of clearing your mind of any internal thoughts. Guided meditations now exist to make meditation easier to practice. With the advent of the internet, it is now possible to practice āsana (postures) without stepping into a yoga studio. Watching a Youtube video that guides you through poses is now possible from the comfort of your bedroom. These are just a few ways to begin your journey with yoga, but they are still just a fraction of what the yogic system provides. If you choose to take up any of these aspects of yoga, it is extremely important to remain historically and culturally mindful of the practice, making active efforts not to perpetuate stereotypes driven by the wellness movement. I was once a skeptic regarding the benefits of yoga, but knowing how useful it can be and the changes it can make on a neurological level in the brain, I think I’ll find a way to incorporate some yoga practice into my own life. If only I could tell my 10th-grade self that.
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