Is Yoga Therapy More Effective at Treating Depression than Antidepressants and Cognitive Behavioral Therapy?
Stefanie Hahn
Integral Health and Yoga Therapy, California Institute for Human Sciences
IH 505: Introduction to Qualitative and Quantitative Research
Dr. Daniel C. Marston
September 18, 2022
Abstract
Yoga therapy may improve the symptoms of depression more than antidepressants and cognitive behavioral therapy. A yoga therapist's job is to reduce stress and guide a client or patient as they improve their quality of life. In general yoga therapy is a way to reduce stress and improve mood, acceptance of a situation, and by default improve symptoms of depression. Moncrief, et al., (2022), wrote that stress and difficult situations are more likely connected with depression than the previously believed low serotonin levels. Therefore there is a great need for further research on stress and depression and how to improve depression without the use of antidepressants. Yoga therapy incorporates a mind-body-spirit integrated approach to treating depression and this four-way ANOVA study aims to explore if yoga therapy is more effective at treating depression than cognitive behavioral therapy and antidepressant medication.
Keywords: yoga therapy, depression, cognitive behavioral therapy, antidepressants, yoga
Is Yoga Therapy More Effective at Treating Depression than Antidepressants and Cognitive Behavioral Therapy?
Treating depression is an important task in America today. Depression has become a national crisis with approximately one in eight people over the age of 12 years old taking antidepressants and one-quarter of those people have been taking them for longer than 10 years (Bringmann, et al., 2021). There are several medically approved methods for treating depression in the mental healthcare field. Antidepressants are commonly prescribed to treat depression by targeting serotonin levels, though little evidence supports the effectiveness of these drugs on symptoms of depression (Moncrieff, et al., 2022; Bringmann, et al., 2021). Cognitive Behavioral Therapy (CBT) is another widely accepted treatment for depression that utilizes an emphasis on the client’s ability to decide how they want to respond to a situation that may be an underlying factor in depression (Diaz & Murguia, 2015). Yoga therapy also incorporates the CBT model of acceptance and revising belief systems while additionally integrating mind-body-spirit practices to alleviate symptoms of depression.
Review of Literature
Antidepressant Treatment
Emerging studies suggest that antidepressant medication may not be effective at treating depression, despite this method being commonly accepted and widely believed to be the primary course for treatment. A recent meta-analysis examined by Moncrieff, et al., (2022), found that there is little evidence pointing to a correlation between low serotonin levels and the occurrence of depression. 17 studies were examined to analyze the effects of serotonin levels in the brain and symptoms of depression. Research found that depression may be related to an increase in stressful life events. The authors presented the questions of why the serotonin theory of depression, with no substantial evidence to support it, is still being perpetuated by professional healthcare providers, as well as the continued practice of prescribing medication prior to any period of allowance for self-regulation intervention. Since 80% of the general public inaccurately believe that depression is caused by a chemical imbalance, patients may be discouraged from trying self-regulation techniques and may turn to a perceived easy fix by taking a medication that can lead to lifelong dependency (Moncrieff, et al., 2022). Finally, Moncrieff, et al., (2022), concluded that the long-term effects of antidepressant medication may actually make a patient more depressed, thereby having the opposite effect of their intended use. From this research analysis, it is fair to question standard practices and to see why implementing complementary and alternative practices to treat depression are areas worth exploring further.
Cognitive Behavioral Therapy Treatment
A more efficient and increasingly popular form of treatment for depression is Cognitive Behavioral Therapy (CBT). CBT utilizes methods that redirect a patient’s thinking about a situation to reframe their thoughts around the stressful or traumatic situations using Yogic Philosophy, Buddhism, Taoism, and Existentialism among others (Diaz & Murguia, 2015). Albert Ellis is credited for developing the CBT therapy outline using Rational Emotive Behavioral Therapy (REBT) and a method known as the ABC Model. In the ABC Model for cognitive behavioral disturbance, the letters are an acronym for A: Activating Event, B: Belief System, and C: Consequences (Diaz & Murguia, 2015). This REBT method is based on yogic philosophies of acceptance, Taoism, and Existentialism as the client is redirected to view their situation differently, accept what is out of their control, and find gratitude for the positive aspects of the situation. Therefore, how a person perceives what happens to them, which is within their control, is a greater factor in depression than the situation itself, which is typically out of their control.
By utilizing the philosophies of yoga including Taoism and Buddhism such as letting go of all-or-nothing thinking, compassion for all beings, and understanding that the ways of the world are greater than oneself, therapists have developed Mindfulness-Based Cognitive Therapy and Mindfulness-Based Stress Reduction. In addition to REBT, utilizing mindfulness practices can be a healthy non-pharmaceutical intervention for the treatment of depression (Diaz & Murguia, 2015). Depression is connected to many aspects of the self including biological, psychological, social, and spiritual factors. “Disturbed circadian rhythm, demanding life events, and stress re-activation modify the transmission of various neurotransmitters and the hypothalamic-pituitary-adrenal axis to contribute to depression” (Bringmann, et al., 2021, p. 2). Because meditation balances these areas of humanism that are related to depression, it has become a highly effective method for treatment and yoga therapists are becoming an important aspect of collaborative care treatment in mental health.
What Separates Yoga Therapy from Yoga Classes?
Today yoga is widely accepted as a suitable complementary and integrative health treatment for mental health. It is important to note the differences between a yoga practice or a public yoga class versus yoga therapy. “The International Association of Yoga Therapists defines yoga therapy as a process of empowering individuals to progress toward improved health and well-being through the application of the teachings and practices of yoga” (Sulivan, et al., 2018, p. 1). A popular Yogic text known as the Bhagavad Gita presents yoga as mastery in action and teaches an individual to live a harmonious, virtuous, and ethical life (Sulivan, et al., 2018). Various lineages of yoga and methods are used in clinical settings without definitions or direct rationale as to why these specific practices are used. Typically there have been four main components defined as yoga in a mental health setting: postures, breath, relaxation, and meditation (Sulivan, et al., 2018). Additionally Sulivan, et al., 2018 wrote the practitioner also benefits from observing the branches of yoga involving observances and avoidances, and other CBT-related practices that are founded in yoga philosophy. Yoga therapy is a more effective treatment for depression than traditional yoga classes because it utilizes aspects of yoga philosophy in addition to just moving the body and breathing.
Yoga is typically practiced in a group setting including general audiences while yoga therapy is individual or targeted to a small group with a specific condition or goal. General yoga often focuses on the teacher, the poses, and a full class while yoga therapy is centered around the client and their independence as they surrender to allow what is currently present in their situation. Yoga therapy empowers the individual student, while yoga is dependent on the teacher’s instruction. Yoga therapists have a defined scope of practice and have developed mastery-level knowledge through advanced training (Bhavanani, et al., 2019). Poses in yoga are often alignment-based and uniform as they are copied from instructor to student, however in yoga therapy poses are adapted based on each client’s needs, ability, injuries, and the effect they will have on the individual. Student lifestyle modification is not necessary for involvement in yoga classes and there is minimal accountability for a student to modify their habits or lifestyle versus the expectation that a student will adjust and adapt along with their yoga therapy treatment plan and take responsibility for their lifestyle choices. Unlike basic yoga teacher training, yoga therapists have an additional understanding of various medical conditions and a deeper education on the philosophy of yoga required for the individual treatment of patients with depression among other medical conditions (Stephens, 2019). It is important to note that yoga therapy training can vary and may not be widely understood in the healthcare community. Another important note is that patients with mental health conditions such as depression may not be best served by attending a traditional yoga class and that additional training by a yoga therapist is needed to assist in relieving symptoms of clinical depression (Stephens, 2019).
Another way to distinguish the difference between general yoga and the use of yoga therapy to improve mental health conditions is the use of Salutogenesis and Eudaimonia. Salutogenesis is client-centered care that specifies areas of a person's life that may be the cause of health and well-being and focuses on improving overall wellness. Eudaimonia is a type of self-actualization where the participant examines the meaning and value in their life (Bhavanani, et al., 2019). By examining the whole person, not just their diagnosis, a yoga therapist is able to help the participant address their depression without the client attaching their identity to the depression or diagnosis (Bhavanani, et al., 2019).
Also, note there is a distinction between yoga therapy and yogapathy. Yogapathy is the focus on using yoga to treat a targeted illness, injury, or mental state. It is important to note that a yoga therapist may initially work with a client using yogapathy in an effort to reduce acute pain and establish trust but an overall long-term goal is to work towards balance and well-being in all areas of the body, mind, lifestyle, and environment. Yoga therapy is a self-study and a continuous process of transformation throughout life's changes and challenges while yogapathy is directed toward alleviating a specific symptom (Bhavanani, et al., 2019).
Many yoga therapists face a lack of cohesion in defining yoga therapy and how it differentiates from yoga. There is a need for a common understanding so that yoga therapy can be more widely integrated into healthcare settings. To have a universal understanding of yoga therapy practices there should be a framework for definition which includes physical postures (asana), breathing practices (pranayama), meditation, and self-disciplines, such as non-harming and truthfulness which are part of the yamas and niyamas of yoga philosophy. When all the branches of yoga are being utilized and working towards balance, the participant can change their perspective on their situation and reduce suffering and depression (Sulivan, et al., 2018). Yoga therapy is effective because it allows for a path where an individual can alleviate suffering by observing the mind and habits and then creating new patterns and changing their relationship to the suffering. Depression can be alleviated when a person can adjust their thinking and develop tolerance and acceptance toward their situation.
Yoga Therapy Treatment
Mental health related disorders such as depression can be observed biomechanically by a change in hormones before and after yoga therapy. While a simple practice involving some yoga poses may have benefits on an individual's well-being, there are notable changes in hormones when a client practices yoga therapy including philosophy and observation of habits. With the utilization of all branches of yoga, compared to practices that focus solely on poses, the reduction of depression and anxiety has been noted by reduced cortisol levels in the participant’s saliva. By adding the practices of breathing, meditation, and ethical principles a person can develop value, meaning, and purpose in their life and alleviate symptoms of depression (Sulivan, et al., 2018).
A major aspect of yoga therapy is the co-creative assessment process that occurs between the client and the yoga therapist. A yoga therapist should be addressing the physical, mental, breath, and spiritual bodies as well as trauma, habits, and philosophy. Taking lessons from these ancient yogic texts can alleviate suffering and help a patient change their relationship to the disease, illness, and suffering. Yoga therapy can improve the mental health of a patient by increasing their own self-worth and well-being. When a client can improve their self-concept and well-being they can improve immune function regardless of their age, gender, physical abilities, and presence of illness or disease. By understanding and addressing the founding principles of yoga, the yoga therapist takes attention away from a person’s individual diagnosis and emphasizes overall well-being and contentment (Sulivan, et al., 2018).
Bhavanani, et al., (2019), pointed out that yoga therapy is not a stand-alone solution, but rather co-functions within the medical environment to collaborate with the client’s medical treatment team. Yoga therapy is a collaborative effort between the yoga therapist and the client, not a prescriptive one size fits all class and is focused on the client’s goals and self-exploration. Yoga therapy helps to improve an individual’s belief systems and cultivates perseverance and an ability to adapt to life’s challenges (Bhavanani, et al., 2019).
Yoga therapy uses intake assessments and measures progress towards a targeted goal, such as reducing anxiety, PTSD, and depression. A traditional yoga class mostly deals with asana (poses) and pranayama (breathing), compared to Yoga therapy which includes asana, pranayama, but also involves meditation and observing the habits of the mind, targeting a balance within the subtle energy symptoms (doshas, chakras, gunas, and koshas) to improve symptoms of depression and co-occurring disorders. Yoga therapy empowers a participant to examine the self and make the necessary changes on their own with at-home assignments and self-reflections (Boynton, 2014). Yoga therapy utilizes worksheets, self-assessment questionnaires, and analysis by the yoga therapist to highlight lifestyle choices that may be contributing to the depression. Additional homework assignments may include implementing meditation, yoga asana practice, breathing exercises, or Ayurvedic dietary changes.
Rationale
Current treatments for depression typically only address one or two components of the mind, body, and spirit connection, and fail to understand the bio-psycho-social-emotional-spiritual connection to depression (Boynton, 2014). CBT is proven effective in treating depression and was created by adapting ancient principles of yoga using acceptance and commitment as therapy. Since CBT only addresses one of the eight branches of yoga, then it is worth examining if adding the other seven limbs of yoga as practiced in yoga therapy would reduce symptoms of depression. CBT interventions help reduce symptoms of depression, but they do not help all individuals across all backgrounds and ages (Boynton, 2014). “A program that integrates all the life aspects of mind, body, and spirit may allow participants to balance their whole being and find greater improvements of overall well-being” (Boynton, 2014, p. 242) and clinical yoga therapy to treat depression aims to be that program.
Yoga therapy can be an effective lifestyle change that has a positive impact on people with depression. Bringmann, et al., (2021), claimed that research showed antidepressants have little effect on depression and they highlighted a need for improved treatment plans including the implementation of yoga therapy to treat depression. "On a neurophysiological level, meditation has been shown to improve both local and systemic biomarkers of neuroplasticity, to reduce stress-related autonomic and endocrine responses, and to increase neural activity in brain regions of affect regulation and attention control” (Bringmann, et al., 2021, p. 1). Yoga therapy offers a wellspring of potential breakthroughs in mental healthcare and by tapping into this ancient modality, therapists have the ability to become pioneers on the forefront of contemplative care.
Because yoga therapists have extensive training on various medical conditions and a deep understanding of the philosophy of yoga as a whole they are more equipped than a yoga teacher to provide individual treatment for patients with anxiety and other health imbalances. Yoga therapy also provides a tool that the patient can implement on their own, with few side effects, whether they are on medication or not (Stephens, 2019). Mindfulness-based yoga therapy practices allow the patient to accept their situation, thoughts, or emotions without judgment or attachment. A different name for the yoga therapy approach is Mindfulness-based Cognitive Therapy (MBCT), which can help ease stress, depression, and anxiety. Meditation can be initially difficult for patients with depression, however, mindfulness can be practiced simply by becoming self-aware during daily events and contemplation (Stephens, 2019). Yoga therapy including meditation, breathing, belief systems, and poses promotes balance and restoration in the nervous systems, improves rational thinking in the prefrontal cortex, and calms the amygdala, responsible for the body’s stress response.
Methodology
Design
Researchers in this study will examine quantitative data analysis and testing using a four-way Analysis of Variance (ANOVA) between four groups using different methods to treat depression. Similar studies have measured previously identified biomarkers to study the effects of yoga and yoga therapy on a participant. Practices associated with yoga such as deep relaxation, yoga pose movement, breathing, and meditation are known to lower the stress hormone cortisol and increase oxytocin, serotonin, and melatonin. Other notable biomarkers to examine are activity in the HPA Axis and gamma-aminobutyric acid (GABA) activity (Stephens, 2019; Varambally & Gangadhar, 2020).
Sample Participant Demographics
The study will include participants at least 18 years old, who have been diagnosed with mild or moderate depression, or have self-disclosed symptoms of depression and achieve a score higher than 10 on the Beck Depression Inventory. Bringmann, et al., (2021), conducted a similar study on depression using Mindfulness Intervention and outlined the criteria for depression as persistent sadness, low mood, loss of interests or pleasure, fatigue or low energy, disturbed sleep, poor concentration or indecisiveness, low self-confidence, poor or increased appetite, suicidal thoughts or acts, agitation or slowing of movements, and guilt or self-blame. This study will use the same basis on criteria for depression and participants with depression and co-occurring diagnoses will be noted in the research findings.
Participants will be from or living in the United States at the time of the study and divided into four regions: Northeast, Southern, South Western, and Pacific Northwest/ Midwest. 160 subjects will be studied and divided into 40 participants from each region. Subjects will be from a mixed variety of ethnicities, genders, ages (all over 18 years), and financial statuses. Participants will be found for the study by reaching out to local therapists, yoga therapy centers, universities, and other community spaces by promoting interest in participation in the study through word of mouth and referrals.
Ethical Considerations
Informed consent will be obtained from the participants and the expectations for the study will be clearly defined for each group. The participants receiving yoga therapy will have an individual yoga therapy plan designed specifically for them based on their status of physical ability as well as their mental and energetic states so that injuries, traumatic recollection, and treatment plan regression can be avoided or minimized. Participants receiving antidepressant treatment have been previously diagnosed and prescribed medication from their primary mental healthcare provider and no adjustments will be made to their existing pharmaceutical plan. Participants receiving CBT will be treated by clinically licensed Cognitive Behavioral Therapists.
Researchers
Researchers and assistants will be able to study participants in the same four regions and will consist of two yoga therapists per region, four cognitive behavioral therapists per region, and four research aides per region responsible for taking vital signs and collecting other data such as urine samples. Researchers will work within the scope of their assigned role exhibiting professionalism, discretion, and ethical sovereignty.
Procedure
This four-way ANOVA will examine the variation of results within and between four groups of study. Participants will be classified into two categories Group 1): receiving antidepressants for depression or Group 2): not receiving antidepressants for depression. Group 1 will then be randomly divided into two more groups: a) the control group only receiving antidepressants for depression, b) receiving antidepressants and participating in Cognitive Behavioral Therapy. Group 2 will also be randomly divided into two groups: c) Yoga Therapy Intervention, and d) Cognitive Behavioral Therapy. All participants will provide written informed consent after receiving a full explanation regarding the study protocol and before randomized assignment to their group. Participants will be informed of the assignment after randomization.
Control Group
Group A: Control Group: Participants only receiving antidepressants during a 12-week study consisting of weekly assessment by a research assistant qualified to administer Beck Depression Inventory assessment, weekly urinalysis measuring oxytocin, cortisol, serotonin, and gamma-aminobutyric acid (GABA) levels, and weekly monitoring of the major five vital signs: blood pressure, pulse, temperature, respiration, and weight.
Experimental Groups
Group B: Participants receiving Cognitive Behavioral Therapy and antidepressants during a 12-week study consisting of 45 minutes per week of Cognitive Behavioral Therapy by a certified CBT therapist, weekly assessment by a research assistant qualified to administer Beck Depression Inventory assessment, weekly urinalysis measuring oxytocin, cortisol, serotonin, and gamma-aminobutyric acid (GABA) levels, and weekly monitoring of the major five vital signs: blood pressure, pulse, temperature, respiration, and weight.
Group C: Yoga Therapy Group participating in a 12-week study consisting of weekly assessment and treatment by a licensed yoga therapist. Yoga Therapists will implement the objectives outlined in detail in Figure 1 in the participants’ treatment plan. Participants will be assessed on the following five Koshas: their physical state (posture, pain level, injury), mental state, the state of their breath, spiritual state, and energetic state including the subtle systems of Doshas, Chakras, and Gunas. The participants will receive individual instruction of an eight-limbed yoga practice designed specifically for that participant including five minutes of pranayama (breathing exercises), 40 minutes of yoga asana followed by five minutes of guided meditation with a focus on pratyahara (withdrawing the senses), and dharana (concentration) and 10 minutes of guided dhyana (meditation) of yoga nidra utilizing the ten Yamas (Community Ethics) and Niyamas (Personal Observances) of yoga philosophy with the guidance directed towards working to Samadhi (Surrender to something greater than oneself). Within the 12-week study, each of the ten yamas and niyamas will be introduced, with the first week as a general introduction and week 12 as a conclusion and summary of the previous weeks. Weekly assessment by a research assistant qualified to administer Beck Depression Inventory assessment, two urinalyses per yoga therapy session measuring oxytocin, cortisol, serotonin, and gamma-aminobutyric acid (GABA) levels. The first urine sample will be taken at the start of the yoga therapy session and the second weekly urine sample will be collected after the yoga therapy session, and weekly monitoring of the major five vital signs: blood pressure, pulse, temperature, respiration, and weight. Vital signs will be taken before and after each weekly yoga therapy session.
Group D: Cognitive Behavioral Therapy participants in a 12-week study consisting of 45 minutes per week of Cognitive Behavioral Therapy by a certified CBT therapist, weekly assessment by a research assistant qualified to administer Beck Depression Inventory assessment, weekly urinalysis measuring oxytocin, cortisol, serotonin, and gamma-aminobutyric acid (GABA) levels, and weekly monitoring of the major five vital signs: blood pressure, pulse, temperature, respiration, and weight.
Measurement
Data collection for the five major vital signs: blood pressure, pulse, temperature, respiration, and weight will use standard instruments for measurement: blood pressure cuff (sphygmomanometer), pulse oximeter, thermometer, spirometer, and a scale. Participants will also undergo a urinalysis measuring oxytocin, cortisol, serotonin, and gamma-aminobutyric acid (GABA) levels administered by the research assistants.
Using the Beck et al., (1996), Beck Depression Inventory (BDI-II) to measure self-identified levels of depression, participants will be asked 21 questions rating on a scale of 0-3. A higher score on the questionnaire indicates a higher level of depression. Starting with the first week as week one, each odd number week the research assistant will administer the test at the start of the session and on even number weeks, the test will be completed at the end of the session.
Yoga Therapists will administer additional self-assessments to Group C to study the participants' energy levels using questionnaires developed for this study (see appendix A). Yoga therapists will examine the assessments and utilize the results to implement strategies to work toward balance in the participants' subtle energy systems of Koshas, Doshas, Chakras, and Gunas.
Results Analysis
This study will use quantitative data to examine if yoga therapy treatment decreases symptoms of depression more effectively than cognitive behavioral therapy and antidepressant medication. Data will be collected from urinalysis examining hormone levels before and after treatment as well as any changes in vital signs. Depression levels for each participant will be studied before and after treatment for each group using the Beck Depression Inventory (BDI-II), a lower score after treatment would indicate that the participant’s depression has lessened.
If yoga therapy is effective at lessening symptoms related to depression, quantitative data will show that after receiving yoga therapy for 12 weeks participants will score lower numbers on the Beck Depression Inventory, have lower levels of hormones associated with depression, and an increase in hormones associated with homeostasis in the body including balanced nervous systems, lower blood pressure, and improved respiration quality. To examine if yoga therapy is more effective at treating depression than cognitive behavioral therapy and antidepressant medication, research analysis will have to conclude that participants receiving yoga therapy treatment for depression have more positive results than the other three groups being treated without yoga therapy.
Discussion
This research proposal presented on how yoga therapy incorporates the mind-body-spirit integrated approach to treating depression and will study if yoga therapy is more effective at treating depression than cognitive behavioral therapy and antidepressant medication. The quantitative data analyzed in this study has the potential to open new doors for yoga therapists seeking to clinically treat patients with depression and establish greater respect and opportunities within the medical community.
This study, like all research studies, could have possible research bias and limitations. A potential bias may be that yoga therapists will be more likely to assume that yoga is a more effective method of therapy than the other three methods studied. Similarly, CBT therapists may be more likely to believe that their treatment will demonstrate the most positive results and participants receiving antidepressants may assume they will have the most improvement. Another limitation could be the measurement of serotonin levels and their relationship with depression since there are mixed beliefs in the medical community over whether or not serotonin theory accurately measures levels of depression. Researchers conducting this study are aware of this possible limitation and hope to correct it by also measuring cortisol, GABA, and oxytocin levels as well as vital signs and depression inventory.
Additional research studies could duplicate the model presented in this study and gather more data from a greater sample population all over the world. It would also be beneficial to replicate the methodology presented in this paper and study yoga therapy’s efficacy on other mental and physical health complications compared to that of their surgical or pharmaceutical counterparts such as in the areas of anxiety, trauma and addiction recovery, multiple sclerosis, heart disease, amputation recovery, dementia, Parkinson’s disease and so much more.
References
Bardoczky, G. I., Engelman, E., & d'Hollander, A. (1993). Continuous spirometry: an aid to
monitoring ventilation during operation. British journal of anaesthesia, 71(5), 747–751.
https://doi.org/10.1093/bja/71.5.747
Beck, A.T., Steer, R.A., & Brown, G.K. (1996). Beck Depression Inventory (BDI-II): Manual
and Questionnaire. The Psychological Corporation.
Bhavanani, A. B., Sullivan, M., Taylor, M. J., & Wheeler, A. (2019). Shared foundations for
practice: The language of yoga therapy. Yoga Therapy Today, 19, 44-47.
Boynton, H. M. (2014). The healthy group: A mind–body–spirit approach for treating anxiety
and depression in youth. Journal of Religion & Spirituality in Social Work: Social
Thought, 33(3-4), 236-253.
Bringmann, H. C., Bringmann, N., Jeitler, M., Brunnhuber, S., Michalsen, A., & Sedlmeier, P.
(2021). Meditation Based Lifestyle Modification (MBLM) in outpatients with mild to
moderate depression: A mixed-methods feasibility study. Complementary therapies in
medicine, 56, 102598.
Chrousos, G. P., Kino, T., & Charmandari, E. (2009). Evaluation of the
hypothalamic-pituitary-adrenal axis function in childhood and adolescence. Neuroimmunomodulation, 16(5), 272–283. https://doi.org/10.1159/000216185
Diaz, K., & Murguia, E. (2015). The philosophical foundations of cognitive behavioral therapy:
Stoicism, Buddhism, Taoism, and Existentialism. Journal of Evidence-Based Psychotherapies, 15(1).
Moncrieff, J., Cooper, R. E., Stockmann, T., Amendola, S., Hengartner, M. P., & Horowitz, M.
A. (2022). The serotonin theory of depression: a systematic umbrella review of the
evidence. Molecular Psychiatry, 1-14.
Stephens, I. (2019). Case report: The use of medical yoga for adolescent mental health.
Complementary Therapies in Medicine, 43, 60-65. doi:https://2p20f07fs-mp01-y-https- doi-org.proxy.lirn.net/10.1016/j.ctim.2019.01.006
Sullivan, M. B., Moonaz, S., Weber, K., Taylor, J. N., & Schmalzl, L. (2018). Toward an
explanatory framework for yoga therapy informed by philosophical and ethical perspectives. Altern. Ther. Health Med, 24, 38-47
Varambally, S., George, S., & Gangadhar, B. N. (2020). Yoga for psychiatric disorders: from fad to evidence-based intervention?. The British Journal of Psychiatry, 216(6), 291-293.