Yoga for stress and depression- A systematic review of the research evidence
(January 5, 2019)
Stress is a non-specific, conventional response to the demanding situation. It strengthens the mind to cope up with the demanding situation. Depression is a common mental disorder in adolescents. Yoga is believed to be helpful in reducing symptoms of depression. In various research studies, yoga has emerged as evidence and found to be antidepressant intervention. Aim of the present study is to evaluate the evidence from a range of sources of the yogic management of stress and depression.
Research evidence suggests that yoga plays an important role in the management of stress and depression. Yoga is an ancient mind-body practice to enhance mental well-being and positive health. The review was carried out in between July and September 2018.
The review was designed to evaluate the evidence of yoga intervention for the management of stress and depression
A guideline of Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) was followed. A broad systematic search was conducted in the field of yoga and psychiatry. Evidence searches were conducted in general databases such as PsycINFO, PubMed, and Frontiers media website. Eight studies met inclusion criteria and type of study, intervention, design, and type of participants was analyzed.
Out of 2022 research articles, a total of 8 articles were included (6 randomized control study and 2 non-randomized studies). All studies demonstrated positive result, although yoga is not alone for treatment of stress and depression in alternative medicine. The current evidence is very good for yoga as effective in the reduction of stress and depression
Yoga practices such as hatha yoga, yoga therapy, Iyengar yoga may promote positive health and exists as an alternative therapy for stress and depression. Without any guidance, there may risk practicing yoga. Teachers and therapists can help patients to evaluate that yoga has a therapeutic effect. Research evidence is limited. In the future, some other better study design needed like a meta-analysis.
Stress is a non-specific, conventional response to the demanding situation. It is the primary function which prepares the body for physical activity and strengthens the mind to cope up with the demanding situation. It prepares the body for flight or fight response against stressor . Stress is a basic response pattern where we react physically, emotionally, and psychologically to various conditions, demands in our life. Stress is defined as the inability to cope with a difficult situation to one’s mental, physical, emotional, and spiritual well-being . It is said that stress is a physiological response to excessive emotional challenges or innate demand . Stress is the physiological response placed on the body when one copes with the demand. The maintenance of life depends on keeping our internal milieu means interstitial fluid constant in order to face a changing environment  called this ‘homeostasis’. Effects of anything that seriously imbalances the homeostasis is called as stress . Stress according to yoga is an imbalance. Imbalance at mental and physical levels, it is the speed of mind against a demanding situation which generates pain and leads to ailments and diseases. At the psychological level, the imbalances lead to conflicts. At the physical body, the imbalance happens due to disturbances at the neuroendocrine system and neurotransmitter level. Emotional imbalances can be identified in the form of strong likes and dislikes. Likes and dislikes bring imbalances in vital energy which percolates to the physical body causing stress symptoms .
Depression is a disabling prevalent mental disorder characterized by low mood, disturbed motor behavior, negative emotions, lack of pleasure, retardation of the cognitive process, and disturbed sleep . Depression is a common psychiatric disorder and it is a chronic condition among medical illnesses. This major psychiatric disorder is prevalent across cultures although depressive symptoms vary in distinct cultures . In India, estimate the prevalence of depression has varied from 1.6 % to 3.8% and this is measured in various samples on diagnostic criteria by using screening tools . Depression is a common mental disorder in adolescents . The prevalence rate of depression in adolescents was 28 % in low and middle-income countries . The previous study reported that the prevalence of depression has been increased among all population and especially in patients aged 15 to 60 years. It shows that 25.5 % population were having no depression, mildly depressed 31.8 %, 14.5 % were borderline depressed, moderately depressed 12.7 %, severely depressed 7.3 %, and 8.2 % were extremely depressed . An estimate of the lifetime prevalence of stress among adolescents and young adults is ranged from 5 % to 70 % across the world. In an Indian study, prevalence was 20 % ranged from mild to severe . A descriptive cross-sectional study was conducted among women staff in Delhi for a period of six months. A sample of 345 women was selected with equal proportion. Prevalence of stress among these working women was 64.6 % that is 223 out of 345 . It is believed that stress-related illness is the one reason for the increase in health problem during the last decade in a number of European countries . In a Swedish population aged 16-84, mild stress prevalence was 13 % and 3 % reported severe stress .
¬¬Yoga is most common mind-body and health care practice which are originated more than 3000 years ago in India. Yoga practice consists of four components: physical exercise, breathe control, relaxation, and meditation . Yoga makes a bridge between mind and body through a series of postures, breathing practices, relaxation techniques, and meditations. Yoga has several practices which are found to be an effective tool in managing stress levels . There is evidence that yoga-based therapies reduce depression. Yoga found to be as a treatment for depression better than other care and exercises . Yoga is believed to be helpful in reducing symptoms of depression. In various research studies, yoga has emerged as evidence and found to be antidepressant intervention .
Aims and Objective
The aim of the present study is to evaluate the evidence from a range of sources of the yogic management of stress and depression/depression symptoms.
Summary of search strategy
A broad search for psychiatric research and clinical research was carried out. Evidence searches were conducted in major medical, psychological, and scientific databases. All citations were done from relevant research articles and specialized books. Relevant journals and other websites are also included in the search. The search is also included the yoga topics and psychiatric topics.
The following list of the databases was taken in search from July 2018 to September 2018.
General Databases: Google scholar, PsycInfo, Pubmed/Medline, Frontiers media website
Relevant Yoga websites: Bihar school of Yoga, International Journal of Yoga- Philosophy, psychology, parapsychology, International Association of Yoga Therapists
The following keywords were used for the search of yoga, stress, and depression in Pubmed (Medline), PsycInfo, Frontiers media, and Google scholar: Yoga Therapy & stress, Stress, and Yoga, Yoga for depression and Yogic management for stress & Depression. The search strategy was adapted for each database.
Filtering of the articles
The entire searched research article was carried out by one researcher. The relevant article was categorized by study type, topic type, and design type. The following basic categories were used: Self as control design, Case studies, randomized control trials, surveys, qualitative research, and other research studies.
Inclusion criteria for research articles
Types of study
All the clinical studies, psychological and psychiatric studies, Yoga therapeutic studies were included in the review. Only the full-length research articles and published manuscripts were included and other articles were excluded because of lack of detail of outcome measures, data analysis, and literature study. The English language was imposed at the time of the search stage and filtering stage.
Types of participants/samples
Those research studies were included in which participants suffered from general stress, depression, and depressive disorder. Research studies in which participants were suffering from depression identified by inventory, measurement scale, and participants prone to be depressive and stressed were also identified.
Studies with a distinct intervention like general yoga, pranayama (controlled breathing), and yoga-based physical exercise were included.
Stress-measuring tools and scales to measure depression or depression symptoms of participants.
Data tabulation and extraction
Data was tabulated systematically on the basis of inclusion/selection criteria. Data were extracted including details of participants, research study, and design of the study, the intervention, the outcome measures, and results. For each study, a method of randomization, sampling method was recorded. In data, reporting of baseline characteristics, variables, and outcome measures demonstrated. Data extraction for each study was conducted solely by one investigator. Each research studies were reviewed two to three times by the researcher, and the discrepancies found in data extraction were resolved by discussion with another investigator.
Results: Electronic or online searches resulted in 2022 in total. Out of all, 110 full-length articles were included for review according to pre-determined inclusion criteria; finally, 8 eligible research articles met other inclusion criteria. The detailed procedure of trails section is shown in Table 1.
Table 1: Detail procedure of trails selection and search process
Systematic reviews: During the search, there were no systematic reviews found on yoga for stress, depression or depressive disorder. In a systematic review, Yoga is included as complementary and alternative management for stress, depression, depression symptoms.
Randomized or non-randomized control study: Eight studies were found and included in the summary table. All studies were controlled trials; out of eight, six studies were randomized and two were non-randomized. In all six studies, the inclusion criteria were a psychiatric and psychological variable like stress, depression, depressive disorder. In the other two non-randomized studies participants were suffering from depression, perceived stress, as determined by the author through measurement scale.
Other studies: No relevant qualitative research studies were found during the search
Table 2: Summarization of evidence-based studies
Description of each study: Table ‘2’ represents a breakdown of study methodology and main results. In a prison-based study, there was a significant reduction of stress, psychological distress in prisons after 10-weeks of yoga practice. Total 100 participants were recruited from seven British prisons. Participants were randomly divided in two groups- experimental group (n= 45) and control group (n= 55). Experimental group practiced yogasana and meditation for ten weeks. Participants in the yoga group showed a reduction in stress, psychological distress (P<0.001) compared to participants in the control group . In a quasi-experimental pre-post study, there was a significant decrease in stress and depression in 52 women with average age 33 years. A series of hatha yoga postures, breathing techniques, and meditations were incorporated for them about 4 weeks. They were practice 60-70 minute’s yoga 3 times per week. Participants were assessed on the DASS-21 (Depression Anxiety Stress Scale) before and after the intervention . Another single group pre-post study, Vinyasa yoga style, and military cultured approach showed that stress reduced both statistically and clinically in 18 veterans of military service participants. They were asked to practice vinyasa yoga for 60 minutes every day for about 6 weeks. They were assessed Post-traumatic stress military version before and after the intervention . In another randomized control study, total 46 caregivers of Alzheimer patients participated in this study. Participants randomized in two group- Yoga and compassion meditation program (n= 25) group and control group (n= 21). Participants of experimental group have practiced series of hatha yoga exercises such as postures, pranayamas, meditations, and compassion meditations. Whereas, participants in the control group underwent physiotherapy-based exercises for two months. Participants of both groups were assessed on LSSI (Lipp’s Stress Symptom Inventory), BDI (Beck Depression Inventory), and BAI (Beck Anxiety Inventory) before and after the intervention. The experimental group (YCMP) demonstrated a reduction of stress (P<0.05), anxiety (P<0.001), and depression (P<0.00001) levels compared to the control group .
In a hospital-based randomized study, 300 cardiac patients of Narayana hrudayalaya super specialty hospital were participants in the study. They were randomized into two groups- experimental group (n= 150) and control group (n= 150). Participants of experimental group undergone with an integrated approach of yoga therapy and control group’s participants undergone with physiotherapy-based exercises. The duration of the intervention was 1 hour per day till 5 years and 30 minutes cardiac rehabilitation program was common in both groups. After 5 years they underwent with coronary artery bypass graft surgery. They were assessed on PSS (Perceived stress scale), Positive-negative affect scale, and HADS (Hospital anxiety depression scale) before and after the surgery. The results showed that at the end of 5 years; mental health (P= 0.05), Perceived stress (P= 0.01) improved significantly in both groups. This study suggests that long-term yoga and physiotherapy-based exercises reduce stress in cardiac patients . In a previous medical based randomized study, total 150 females suffering from menstrual problems were recruited from Department of Obstetrics and Gynecology, CSM medical university. During the study total, 34 subjects dropped out due to some reasons. Therefore 126 female subjects became the final sample size for the study. Subjects randomized in two groups- Intervention group (Yoga; n= 65) and control group (without yoga; n= 61). The intervention group practiced yoga nidra about 35 minutes per day, 5 days a week for 6 months. Participants of both groups were assessed on HAM-A (Hamilton anxiety rating scale) and HAM-D (Hamilton depression rating scale) before and after 6 months. The results showed that there was a significant reduction of anxiety (P<0.003) and depression symptoms (P<0.02) in the intervention group compared to the control group . In one 3-armed randomized control study, 178 adult workers participated in the study. They randomized in to three groups- Meditation group (n= 59), active control group (n= 56), and wait-list control group (n= 63). Sahaja yoga that is mental silence for meditation group and relaxation techniques for the active control group was incorporated as an intervention (1-hour evening session twice weekly for 8 weeks). There was no treatment for the participants of the wait-list control group. All participants were assessed on PSQ (Psychological strain questionnaire), OSI (Occupational stress inventory), DD (Depression dejection) before and after eight weeks of intervention. The results reported that there was a significant reduction of depression (P<0.019) and stress (P= 0.026) symptoms in the meditation group compare to active control and wait-list control group . In another 3-armed randomized control study, total 72 distressed females included in the study and randomized into three groups having 24 subjects in each group- Yoga group ‘1’, yoga group ‘2’, and wait-list control group. Participants of both 1st and 2nd group undergone series of Iyengar yoga practice for 90 minutes over 3 months. Total yoga session for group 2nd (24 sessions) was more than the 1st (12 sessions) group. Participants were assessed by using CSS (Cohen stress scale), ADS-L 9Allgemeine depression scale), QOL (Quality of life) before and after three months. Results showed that stress (P= 0.003), and depression (P= 0.008) reduced significantly in the intervention group compare to the control group .
The relationship between yoga and mental well-being is not well understood in young adults. In my view, this is the first combined a systematic review of yoga for stress and depression. Based on the results of the present review, the pooled studies indicated that yoga therapy may be more beneficial for the management of stress and depression. As a common alternative medicine, yoga may be helpful in treating depression because it leads to the good mood through combined practices to enhance positive health at physical, emotional, and spiritual level . It is said that stress is a non-specific response to the demanding situation. The interplay among stressors, the environmental condition appears to be a key cause of depression. When an individual come across psychological and physiological challenges, the stressors influence the risk of depression in them. Stress and depression are correlated with each other, individual suffer from depression because of stress and stress may be a reason of depression . The possible biological mechanism of how yoga affects the mood and reduces stress-depression can be understood through a figure. There is a beneficial effect of yoga for stress and stress-related disorders such as depression  [See Figure 1]. A number of controlled trials both randomized and non-randomized that tested in this review and described yoga as an intervention for stress-depression. Eight studies were reviewed in which participants were suffering from stress or depression, and all studies demonstrated positive results. However, overall reporting of methodology in the study was poor and there were many methodological mistakes in these studies. The best methodological procedure may provide better results in the future study. In this present review, the scientific literature of yoga and mechanism of how yoga works is well explained. Finally, it is not possible to report that yoga is the perfect tool to treat depression but yoga may exist as good complementary and alternative therapy for stress and depression.
Figure 1: Mechanism of how yoga reduces stress and depression
This present systematic review which is based upon the existing literature, suggests that there is preliminary evidence that yoga may be effective interventions to alleviate stress, depression and depressive symptoms. Emphasizing the therapeutic effects of yoga therapy for treating stress, depression, and depression symptoms are very important because it provides a useful option to manage health for patients with stress, distress, and depression. It must be addressed that most of the empirical studies may have impacted the findings. The randomized control studies with eligible study design were incorporated to establish effects of distinct yoga styles (hatha yoga, Iyengar yoga, and general yoga) for stress and depression, and these yoga styles can be practiced for manage stress and as an alternative therapy for depression.
I thank the Kautilya Entrepreneurship and Management Institute (KEMI)-Jain University to provide a platform to do research. I thank my colleagues both staff members and faculties for their continuous support. I also would like to thank my beloved family members (father, mother, and brothers) for their consistent support.
 R. Nagarathna and H. R. Nagendra, New Perspectives in Stress Management, First Edit. Bangalore: Swami Vivekananda Yoga Prakashana, 1986.
 B. L. Seaward, “Managing Stress: Principles and strategies for health and well-being (6th ed.),” Manag. Stress Princ. Strategy. Heal. well-being (6th ed ) xxi, 576 pp Boston, MA, US Jones Bartlett Publ. US, 2009.
 D. Juniper, “Leisure counseling in stress management,” Work Study, vol. 52, no. 1, pp. 7–12, Feb. 2003.
 C. Bernard, An introduction to the study of experimental medicine. London, 1865.
 S. Cohen, D. A. Tyrrell, and A. P. Smith, “Psychological stress and susceptibility to the common cold [see comments],” N Engl J Med, vol. 325, no. 9, pp. 606–612, 1991.
 H. Selye, The Stress of the Life. 1956.
 American Psychiatric Association., Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-Text Revision (DSM-IV-TR). 2000.
 D. Bhugra, K. R. Gupta, and B. Wright, “Depression in North India comparison of symptoms and life events with ocher patient groups,” Int. J. Psychiatry Clin. Pract., vol. 1, no. 2, pp. 83–87, Jan. 1997.
 J. A. den Boer, “Psychopharmacology of comorbid obsessive-compulsive disorder and depression.,” J. Clin. Psychiatry, vol. 58 Suppl 8, pp. 17–9, 1997.
 K. R. Merikangas, E. F. Nakamura, and R. C. Kessler, “Epidemiology of mental disorders in children and adolescents.,” Dialogues Clin. Neurosci., vol. 11, no. 1, pp. 7–20, 2009.
 S. Yatham, S. Sivathasan, R. Yoon, T. L. da Silva, and A. V. Ravindran, “Depression, anxiety, and post-traumatic stress disorder among youth in low and middle-income countries: A review of prevalence and treatment interventions,” Asian J. Psychiatr., Oct. 2017.
 M. Ghous, S. Gul, F. A. Siddiqi, S. Pervaiz, and S. Bano, “DEPRESSION ; PREVALENCE AMONG DEPRESSION ;” Prof. Med. J., vol. 22, no. 2, pp. 263–266, 2015.
 S. Sahoo and C. R. J. Khess, “Prevalence of Depression, Anxiety, and Stress Among Young Male Adults in India,” J. Nerv. Ment. Dis., vol. 198, no. 12, pp. 901–904, Dec. 2010.
 M. Parashar, M. Singh, J. Kishore, R. Pathak, and M. Panda, “Prevalence and correlates of stress among working women of a tertiary health center in Delhi, India,” Indian J. Med. Spec., vol. 8, no. 2, pp. 77–81, Apr. 2017.
 C.-G. Stefansson, “Chapter 5.5: Major public health problems — mental ill-health,” Scand. J. Public Health, vol. 34, no. 67_suppl, pp. 87–103, Jun. 2006.
 M. Henderson, N. Glozier, and K. H. Elliott, “Long-term sickness absence,” BMJ, vol. 330, no. 7495, pp. 802–803, Apr. 2005.
 M. Danielsson and M. Talback, “Public health: An overview: Health in Sweden: The National Public Health Report 2012. Chapter 1,” Scand. J. Public Health, vol. 40, no. 9 Suppl, pp. 6–22, 2012.
 B. Iyengar, Light on Yoga, Revised ed. New York: Schocken Books, 1979.
 N. H. R. Nagaratna R, Integrated approach of yoga therapy for positive health, 2nd ed. Bangalore: Swami Vivekananda yoga prakshana, 2003.
 R. R. Michaels, M. J. Huber, and D. S. McCann, “Evaluation of transcendental meditation as a method of reducing stress.,” Science, vol. 192, no. 4245, pp. 1242–4, 1976.
 L. A. Uebelacker and M. K. Broughton, “Yoga for Depression and Anxiety: A Review of Published Research and Implications for Healthcare Providers.,” R. I. Med. J. (2013), vol. 99, no. 3, pp. 20–2, Mar. 2016.
 H. Cramer, R. Lauche, J. Langhorst, and G. Dobos, “YOGA FOR DEPRESSION: A SYSTEMATIC REVIEW AND META-ANALYSIS,” Depress. Anxiety, vol. 30, no. 11, pp. 1068–1083, Nov. 2013.
 S. Krishnan and A. Prabhakaran, “Yoga and depression,” Indian J. Psychiatry, vol. 54, p. S28, 2012.
 A. C. Bilderbeck, M. Farias, I. A. Brazil, S. Jakobowitz, and C. Wikholm, “Participation in a 10-week course of yoga improves behavioral control and decreases psychological distress in a prison population,” J. Psychiatr. Res., vol. 47, no. 10, pp. 1438–1445, Oct. 2013.
 M. Shohani, G. Badfar, M. Nasirkandy, S. Kaikhavani, S. Rahmati, Y. Modmeli, A. Soleymani, and M. Azami, “The effect of yoga on stress, anxiety, and depression in women,” Int. J. Prev. Med., vol. 9, no. 1, p. 21, 2018.
 R. E. Cushing, K. L. Braun, S. W. Alden C-Iayt, and A. R. Katz, “Military-Tailored Yoga for Veterans with Post-traumatic Stress Disorder.,” Mil. Med., vol. 183, no. 5–6, pp. e223–e231, May 2018.
 M. A. D. Danucalov, E. H. Kozasa, K. T. Ribas, J. C. F. Galduróz, M. C. Garcia, I. T. N. Verreschi, K. C. Oliveira, L. Romani de Oliveira, and J. R. Leite, “A Yoga and Compassion Meditation Program Reduces Stress in Familial Caregivers of Alzheimer’s Disease Patients,” Evidence-Based Complement. Altern. Med., vol. 2013, pp. 1–8, 2013.
 E. Amaravathi, N. H. Ramarao, N. Raghuram, and B. Pradhan, “Yoga-Based Postoperative Cardiac Rehabilitation Program for Improving Quality of Life and Stress Levels: Fifth-Year Follow-up through a Randomized Controlled Trial.,” Int. J. Yoga, vol. 11, no. 1, pp. 44–52.
 N. Srivastava, K. Rani, U. Singh, S. Tiwari, and I. Singh, “Yoga Nidra as a complementary treatment of anxiety and depressive symptoms in patients with the menstrual disorder,” Int. J. Yoga, vol. 5, no. 1, p. 52, 2012.
 R. Manocha, D. Black, J. Sarris, and C. Stough, “A Randomized, Controlled Trial of Meditation for Work Stress, Anxiety and Depressed Mood in Full-Time Workers,” Evidence-Based Complement. Altern. Med., vol. 2011, pp. 1–8, 2011.
 A. Michalsen, M. Jeitler, S. Brunnhuber, R. Lüdtke, A. Büssing, F. Musial, G. Dobos, and C. Kessler, “Iyengar Yoga for Distressed Women: A 3-Armed Randomized Controlled Trial,” Evidence-Based Complement. Altern. Med., vol. 2012, pp. 1–9, 2012.
 R. B. Saper, D. M. Eisenberg, R. B. Davis, L. Culpepper, and R. S. Phillips, “Prevalence and patterns of adult yoga use in the United States: results of a national survey.,” Altern. Ther. Health Med., vol. 10, no. 2, pp. 44–9.
 L. A. Uebelacker, G. Epstein-Lubow, B. A. Gaudiano, G. Tremont, C. L. Battle, and I. W. Miller, “Hatha yoga for depression: Critical review of the evidence for efficacy, plausible mechanisms of action, and directions for future research,” Journal of Psychiatric Practice, vol. 16, no. 1. pp. 22–33, 2010.
 P. M. Barnes, B. Bloom, and R. L. Nahin, “Complementary and alternative medicine use among adults and children: the United States, 2007.,” Natl. Health Stat. Report., no. 12, pp. 1–23, Dec. 2008.
 P. Luyten, S. J. Blatt, B. Van Houdenhove, and J. Corveleyn, “Depression research and treatment: are we skating to where the puck is going to be?,” Clin. Psychol. Rev., vol. 26, no. 8, pp. 985–99, Dec. 2006.
 A. G. Taylor, L. E. Goehler, D. I. Galper, K. E. Innes, and C. Bourguignon, “Top-down and bottom-up mechanisms in mind-body medicine: development of an integrative framework for psychophysiological research.,” Explore (NY)., vol. 6, no. 1, pp. 29–41.
About the Author
Narottam Kumar-He is a research associate and Yoga Instructor at Kautilya Entrepreneurship and Management Institute-Jain University