Can Yoga Treat Depression? The Utilization of Yoga for Adults with Major Depressive Disorder
It is estimated that more than 16.2 million Americans suffer from at least one major depressive episode each year. Current treatment modalities for major depressive disorder include antidepressant medications, therapy, and lifestyle changes. Both medications and psychotherapy have been studied and deemed efficacious choices of treatment. Less research has taken place, however, regarding the relationship of lifestyle changes such as exercise or yoga, and amelioration of depressive symptoms. This is especially true of research about yoga as an alternative treatment to medications rather than as an adjunctive treatment. This paper synthesizes the results of numerous studies that measured the severity of symptoms in adults with major depressive disorder, both before and after their participation in structured yoga programs. These yoga programs were created as specific time-limited interventions for depression and were evaluated against control group activities; comprised mainly of psychoeducation. Our results found that yoga significantly reduces the severity of depressive symptoms in individuals with MDD who fully participated in structured interventions. These findings indicate that yoga may in fact be a suitable alternative therapy for adults with major depressive disorder. More robust research is needed to determine whether or not these findings are replicable, and if they ameliorate depressive symptoms to an extent that warrants replacement of medication with a “prescription” for yoga.
Keywords: Yoga, major depression, major depressive disorder, adults, symptoms, PHQ-9, Beck Depression Inventory, BDI, Montgomery-Asberg Depression Rating Scale
Major depressive disorder (MDD) has a prevalence of 6.7% in adults 18 years of age or older in the United States. The total economic burden associated with MDD is estimated at $210 billion dollars per year and for each dollar of direct cost, it is estimated an additional $1.90 was spent on the indirect costs of MDD, such as loss of workplace productivity (Greenbert et al., 2015). Given both the fiscal burden (direct cost and loss of productivity), and the personal devastation experienced by individuals and their families suffering with this disease, finding evidence-based treatment options remains incredibly important. These efficacious evidence-based therapies may be used as adjuncts to medication or as alternative interventions when medications are not effective. Yoga, an ancient ayurvedic practice that combines certain postures with mindful breathing and meditation, has been suggested as one such treatment.
Background and significance
Yoga was developed 5,000 years ago in India and was first introduced to the United States in 1893 at the World Parliament of Religions in Chicago, IL (Frederick, 2012). Since that time yoga has been suggested as a therapeutic treatment for a variety of chronic health problems. Research studies involving yoga for the treatment of medical disorders have tripled in the past 10 years, however many of these studies have had flaws in design, are lacking in sufficient diversity of subjects, or have had very small sample sizes (Jeter et. al., n.d.). Additionally, there are a variety of schools within yoga and this has made it difficult to study as a single treatment modality. Yoga is considered to be a complementary therapy and is not always distinguished from other forms of complementary treatments in research studies. Nonetheless, as yoga has increased in popularity in the West, insurance companies within the U.S have demonstrated enhanced interest in reimbursement of yoga-based interventions as formal medical treatments. Given the morbidity associated with major depressive disorder (MDD) and its prevalence in the United States, it may significantly improve treatment options and outcomes if yoga is found to be an effective treatment. Currently, health care professionals such as nurse practitioners and physicians have limited evidence-based alternative therapies to recommend if individuals are opposed to traditional psychiatric modalities such as antidepressant medications and psychotherapy. In 2017, the American Foundation for Suicide Prevention (ASFP) found that there were an estimated 1,400,000 suicide attempts and that suicide and self-injury events cost about $69 billion in the United States annually (ASFP, 2019). Given that one of the risk factors for suicide and self-harm is a current or previous history of major depressive disorder, this topic is particularly germane to health care professionals. The intent of this paper was to assess currently available research on yoga therapy as a treatment intervention for adults with MDD and to subsequently evaluate the overall quality of this evidence.
The objective of this paper is to research existing evidence for yoga as a therapeutic treatment for adults with Major Depressive Disorder. The specific question addressed in our synthesis of the evidence is: In adults with major depression, how does yoga affect the severity of their depression symptoms? More specifically, our criteria included adults ages 18-64, with a DSM-5 diagnosis of Major Depressive Disorder. We included all appropriate studies that evaluated a control group and a yoga intervention group. The intervention group must have received a yoga-based therapy of the same duration as the control group’s intervention. Exclusion criteria included control groups that received medication interventions and studies that included individuals with multiple psychiatric diagnoses. We determined that these variables might confound our ability to assess the efficacy of the yoga-based intervention’s effect on treating Major Depressive Disorder. Our outcome measures included validated scales that measure depressive symptoms, such as the BDI, PHQ-9, Montgomery-Asberg Depression Rating Scale, and other symptom-based measurement tools. The overall objective of this paper is to utilize the aforementioned guidelines to search and analyze available research. These findings will help to elucidate whether or not there is sufficient, high-quality, and statistically significant data to answer our question.
The protocol used to perform the review of articles was the Johns Hopkins Evidence-Based Practice: Model and Guidelines. Inclusion criteria included adults between the ages of 18-64 who had a diagnosis of major depressive disorder; only studies that were performed in the United States; studies that explored yoga alone as a treatment modality for depression; studies that utilized either the BDI, PHQ-9, Montgomery-Asberg Depression Rating Scale, or a symptom measurement tool to gauge the severity of symptoms and studies written in English. Exclusion criteria included studies that were performed on children, adolescents, or the elderly; studies that were performed outside of the United States; studies that looked at yoga as a treatment for mental health diagnoses other than major depressive disorder; and studies that compared yoga to a medication treatment. Only articles from 2014 to 2020 were reviewed in this search. Four database searches were performed on October 8th, 2019, on PubMed, CINAHL, SCOPUS, and Embase. The full electronic search strategy included the search terms: “adults” AND “major depressive disorder” OR “major depression” AND “yoga” AND “beck depression inventory” OR “BDI” OR “PHQ-9” OR “Montgomery-Asberg Depression Rating Scale,” OR “symptoms.” Utilizing the aforementioned inclusion criteria and year limits, we selected studies for further review. A PRISMA diagram was created to further organize the studies that were included vs. excluded as well to identify those removed in the deduplication process. Upon initial database search, 329 articles were identified as eligible for general assessment, and 268 articles were identified following completion of the deduplication process. Of the 268 articles that were identified, 244 articles were thrown out for meeting the exclusionary criteria. The remaining 27 full-text articles were assessed for eligibility and ultimately examined fully during the synthesis of this paper. Utilizing the Johns Hopkins Evidence-Based Practice: Evidence Level & Quality Guide, the final 27 articles were sorted into Level I, Level II, or Level III evidence and A, B, or C quality. After full review of the articles above, 17 were removed because either they did not answer the PICO question, or they involved research methodology that lacked the quality and level of evidence standards outlined in the Johns Hopkins Evidence-Based Practice: Evidence Level & Quality Guide. After more rigorous examination, it was determined that several articles did not fully meet the inclusion criteria, and they were also removed. The remaining 10 quantitative articles were pushed forward for the final review set forth in this paper, utilizing Dang & Dearholt’s Appendix D: Definitions of Levels of Evidence. Of these 10 articles, five were of A quality, four were of B quality, and 1 was of C quality. Of the 10 articles, six were Level I, three were Level II, and one was Level III. The 10 articles, as assessed by level and quality of evidence are outlined in Table I below.
- A – Quality
- B – Quality
- C – Quality
Level I Evidence
Level II Evidence
Level III Evidence
Of the level I evidence, all six studies were randomized controlled trials. Of the level II evidence, one was a randomized-controlled trial, one was a quasi-experimental pilot study, and one was an explanatory mixed-method design study. The only article of level III evidence was a non-experimental pilot study. Given that 50% of the articles were of A quality, 40% of the articles of B quality, and 10% of the articles of C quality, there is a reasonable expectation that the results discussed below are of predominantly high and good quality. The sole C quality article was given this rating because of a relatively small sample size and it’s being unblinded. Utilizing Dang & Dearholt’s Appendix H: Synthesis and Recommendations Tool, a synthesis of the 10 articles with their evidence levels and quality was performed. Based upon this synthesis, the overall strength of the evidence was evaluated to be “good and consistent evidence.” From this, the pathway to translation recommended is to consider a pilot of change or further investigation.
Of the 10 articles used in this synthesis paper, the overall study characteristics remained similar. The sample sizes of the articles ranged from the smallest being n = 25 to the largest sample size being n = 101. The total sum of the patients reviewed in these articles is n = 471. These studies were performed in a variety of environments– urban, suburban, and rural. There were a wide variety of ages studied, all adults within the ages of 18-64. All of the participants within these 10 studies were asked to participate in self-report questionnaires such as the Beck Depression Inventory (BDI), Hamilton Rating Scale for Depression, Montgomery-Asberg Depression Rating Scale, PHQ-9, DASS-21, or symptom severity questionnaires, both before and after the intervention of a structured yoga routine was performed.
In Nyer et al. (2019), a community-delivered hatha yoga program for depression found that 52% of participants had a 50% or greater reduction in symptoms on the Hamilton Rating Scale for Depression and 56% of participants had sustained remission after the study concluded. In Nyer et al. (2018), they found similar results in that prior to the yoga intervention, BDI-II scores showed that 9 participants endorsed significant suicidal ideation (SI) and after the intervention, 8 of the 9 participants (88%) reported resolved suicidal ideation on their BDI-II scores. In de Manincor et al. (2016), statistically significant differences were found between the yoga intervention group and the control group in symptoms from the beginning to the end of the study (−4.30; 95% CI: −7.70, −0.01; P = .01; ES −.44). Prathikanti et al. (2017) stated that “The Cohen’s d effect size of yoga in reducing BDI scores was relatively large at -0.96 [95% CI, -1.81 to -0.12]” meaning that the intervention of yoga was extremely effective. In Sharma and Barrett and Cucchiara and Gooneratne and Thase (2017), the yoga intervention showed a greater improvement in both the Hamilton Rating Scale for Depression (HRSD) and BDI-II scores (-9.77 vs 0.50, P = .0032 for HRSD; -17.23 vs -1.75, P = .0101 for BDI-II).