Yoga For Depressive Disorder: Systematic Review And Meta-Analysis

Yoga is an ancient mind-body practice originating in India that combines physical postures, breathing exercises, and meditation.

It offers numerous benefits including improved flexibility, strength, balance, and stress reduction. For mental health, yoga may help manage conditions like depression by promoting relaxation, mindfulness, and self-awareness.

Its holistic approach addresses both physical and psychological aspects, potentially providing a complementary tool for managing mental health alongside traditional treatments.

Moosburner, A., Cramer, H., Bilc, M., Triana, J., & Anheyer, D. (2024). Yoga for Depressive Disorder: A Systematic Review and Meta‐Analysis. Depression and Anxiety, 2024(1), 6071055. https://doi.org/10.1155/da/6071055

Key Points

• Yoga interventions showed a statistically significant small effect on depression severity compared to passive controls, but not compared to active controls. The quality of evidence was rated as very low.
• Yoga was associated with significantly higher remission rates compared to both passive and active controls. The quality of evidence was moderate for passive controls and low for active controls.
• Effects on quality of life were heterogeneous across studies.
• Yoga interventions appear to be safe, though the quality of evidence was very low.
• The research has limitations including high heterogeneity across yoga interventions, potential reporting and expectation bias, and possible publication bias favoring yoga for passive control comparisons.
• Depression is a highly prevalent and burdensome mental health disorder affecting about 3.4% of the global population. Effective, accessible treatment options are urgently needed given the high rates of non-response to standard treatments.

Rationale

Depression is a major global health concern, affecting approximately 3.4% of the population worldwide and increasing in prevalence following the COVID-19 pandemic (World Health Organization, 2021).

Standard treatments like psychotherapy and antidepressant medications are not effective for 20-40% of patients with major depressive disorder (Rush et al., 2006).

Given this treatment gap and high non-response rates, there is an urgent need for effective, accessible complementary treatment approaches (Cuijpers et al., 2020).

Yoga has shown promise as a complementary treatment for depression in previous research. Meta-analyses have found beneficial effects of yoga interventions on depressive symptoms (Cramer et al., 2013; Bridges & Sharma, 2017).

However, the efficacy of yoga specifically for clinically diagnosed depressive disorders remains unclear. This systematic review and meta-analysis aimed to update and evaluate the current evidence for yoga as a therapy option for depressive disorders.

Method

This systematic review and meta-analysis was conducted in accordance with PRISMA guidelines.

The following databases were searched: PubMed/Medline, Cochrane Library, Scopus, PsycINFO, and BASE.

Search strategy and terms

The search strategy was built around the keywords “yoga” and “depression”. Full details of the search strategy are provided in the supplementary materials.

Inclusion and exclusion criteria

Inclusion criteria:

• Randomized controlled trials (RCTs)
• Published in English, German, Italian, Spanish, French, Croatian, Russian, Bosnian, or Serbian
• Participants with clinical diagnosis of depressive disorder according to DSM-IV/V or ICD-10/11
• Minimum participant age of 18 years
• Any type of yoga intervention
• Outcomes including depression severity, remission rates, health-related quality of life, or safety

Exclusion criteria:

• Studies investigating depression as a comorbidity of a different primary disorder
• Pregnant participants unless depression diagnosis was unrelated to pregnancy

Extraction of Data

Study characteristics and results were independently extracted by two authors. Discrepancies were resolved through discussion with a third author.

Statistical measures

Random-effects models were used to calculate standardized mean differences (SMDs) with 95% confidence intervals for continuous outcomes and odds ratios (ORs) with 95% CIs for dichotomous outcomes.

The Hartung-Knapp small-sample correction was implemented. Heterogeneity was assessed using I2 and τ2 statistics.

Publication bias was evaluated through visual examination of funnel plots and Egger’s test when at least 10 studies were included in a meta-analysis.

Results

Literature search:

The search retrieved 2,248 unique records. After screening, 24 RCTs with a total of 1,395 participants were included in the systematic review.

Twenty RCTs with 1,333 participants were included in the meta-analyses.

Study characteristics:

• Most studies originated from North America (10 studies) and Asia (8 studies), with 4 from Europe
• 16 studies included patients with major depressive disorder, 6 included mixed populations
• Average participant age ranged from 24.9 to 51.0 years (median 36.7 years)
• The proportion of female participants ranged from 23.8% to 100% (median 76.8%)
• Hatha yoga was the most common type of yoga intervention (9 studies)
• Intervention duration ranged from 4 to 12 weeks (median 8.5 weeks)
• Frequency ranged from 1 to 7 times per week (median 2 times)
• Total contact time ranged from 2 to 72 hours (median 18 hours)

Depression severity:

• Compared to passive controls, yoga showed a statistically significant small effect (SMD = -0.43, 95% CI [-0.80, -0.07])
• Subgroup analysis found a significant effect for major depressive disorder (SMD = -0.47, 95% CI [-0.87, -0.07]) but not mixed samples
• No significant effect compared to active controls (SMD = -0.22, 95% CI [-0.67, 0.23])
• Heterogeneity was substantial for passive controls and considerable for active controls
• Quality of evidence was rated as very low for both comparisons

Remission rates:

• Significantly higher remission rates for yoga vs passive controls (OR = 3.20, 95% CI [1.45, 7.10])
• Also significantly higher vs active controls (OR = 2.04, 95% CI [1.13, 3.69])
• Significant effects for major depressive disorder subgroups in both comparisons
• Heterogeneity was moderate
• Quality of evidence was moderate for passive controls, low for active controls

Quality of life:

Results were heterogeneous across the few studies reporting this outcome, precluding meta-analysis.

Safety:

• No significant differences in adverse events for yoga vs passive controls (OR = 1.00, 95% CI [0.10, 9.98]) or active controls (OR = 0.80, 95% CI [0.08, 8.09])
• Heterogeneity was low for passive controls, substantial for active controls
• Quality of evidence was rated as very low

Risk of bias:

Most studies had some risk of bias due to lack of blinding. Several studies had high risk of bias for missing outcome data due to high dropout rates.

Publication bias:

There was evidence of publication bias favoring yoga for comparisons with passive controls, but not for active controls.

Insight

This systematic review and meta-analysis provides updated evidence on the efficacy of yoga interventions for clinically diagnosed depressive disorders.

The findings suggest that yoga may be effective for reducing depression severity compared to passive controls like waitlist or treatment as usual, though the effect size was small.

Importantly, yoga was associated with significantly higher remission rates compared to both passive and active control conditions.

These results extend previous research by focusing specifically on diagnosed depressive disorders rather than just elevated depressive symptoms.

The significant effects on remission rates are particularly noteworthy, as achieving remission is a key goal of depression treatment.

However, the lack of significant effects on depression severity versus active controls suggests yoga may not be superior to other active treatments.

The heterogeneity in yoga interventions across studies limits conclusions about which specific types, durations, or components of yoga may be most effective.

Future research comparing standardized yoga protocols or isolating key components like meditation and breathing exercises could help clarify the most beneficial elements.

Additionally, more rigorous assessment and reporting of adverse events is needed to better establish the safety profile of yoga for depression.

Implications

The findings have important implications for clinical practice in mental health. Given the high prevalence of depression, treatment resistance rates of 20-40%, and large treatment gaps globally, additional evidence-based interventions are urgently needed.

Yoga represents a promising complementary approach that appears to be safe and associated with higher remission rates compared to both passive and active control conditions.

The results suggest yoga could be considered as an adjunctive treatment option, particularly for patients with major depressive disorder.

It may be especially valuable for individuals who have not responded to or cannot tolerate standard treatments like antidepressants.

The generally good safety profile and accessibility of yoga are additional advantages that could promote uptake and adherence.

However, several factors may influence the effectiveness of yoga interventions. The type, frequency, duration, and specific components of yoga practice likely play a role, though this review could not determine optimal parameters due to heterogeneity across studies.

Patient characteristics such as depression severity, comorbidities, and preferences may also moderate outcomes. Careful assessment and individualized recommendations are warranted when considering yoga as a treatment option.

Strengths

The study had many methodological strengths including:

• Comprehensive systematic literature search
• Clear inclusion criteria focused on diagnosed depressive disorders
• Large sample of 24 RCTs included
• Separate analyses for active and passive control groups
• Subgroup analyses for major depressive disorder and mixed samples
• Assessment of both depression severity and remission rates
• Evaluation of quality of evidence using GRADE criteria
• Assessment of publication bias
• Adherence to PRISMA guidelines for systematic reviews and meta-analyses

Limitations

Several limitations should be considered when interpreting the results:

• High heterogeneity in yoga interventions across studies limits conclusions about specific types or components of yoga
• Lack of blinding in most studies introduces potential for expectation and reporting bias
• Several studies had high risk of bias due to missing outcome data from high dropout rates
• Possible publication bias favoring yoga for passive control comparisons
• Inconsistent and limited reporting of quality of life and safety outcomes
• Samples were predominantly female and white, limiting generalizability to other populations
• Most studies were short-term, with limited data on long-term effects
• Unable to conduct some planned subgroup and sensitivity analyses due to insufficient studies

The heterogeneity in interventions and control conditions is a key limitation that makes it difficult to draw firm conclusions about the most effective types or “doses” of yoga for depression.

The potential for expectation effects and reporting bias due to lack of blinding is also important to consider, particularly for subjective outcomes like depression severity.

These limitations underscore the need for more rigorous, standardized trials to further establish the efficacy of yoga for depressive disorders.

References

Primary reference

Moosburner, A., Cramer, H., Bilc, M., Triana, J., & Anheyer, D. (2024). Yoga for Depressive Disorder: A Systematic Review and Meta-Analysis. Depression and Anxiety, 2024(1), 6071055. https://doi.org/10.1155/da/6071055

Other references

Bridges, L., & Sharma, M. (2017). The efficacy of yoga as a form of treatment for depression. Journal of Evidence-Based Complementary & Alternative Medicine, 22(4), 1017-1028.

Cramer, H., Lauche, R., Langhorst, J., & Dobos, G. (2013). Yoga for depression: A systematic review and meta‐analysis. Depression and Anxiety, 30(11), 1068-1083.

Cuijpers, P., Stringaris, A., & Wolpert, M. (2020). Treatment gaps and the use of treatment approaches for depression in low-income and middle-income countries: A systematic review. The Lancet Psychiatry, 7(11), 901-909.

Rush, A. J., Trivedi, M. H., Wisniewski, S. R., Nierenberg, A. A., Stewart, J. W., Warden, D., … & Fava, M. (2006). Acute and longer-term outcomes in depressed outpatients requiring one or several treatment steps: A STAR* D report. American Journal of Psychiatry, 163(11), 1905-1917.

World Health Organization. (2021). Depression. https://www.who.int/news-room/fact-sheets/detail/depression

Keep Learning

1. How might the placebo effect and expectation bias influence the results of studies on yoga for depression? How could future research designs address this?
2. What are some potential mechanisms by which yoga practice could alleviate depressive symptoms? How could these be investigated more directly?
3. Given the heterogeneity in yoga interventions across studies, how might researchers determine the most effective “dose” and type of yoga for treating depression?
4. How generalizable are these findings to diverse populations globally? What cultural factors might influence the effectiveness of yoga interventions for depression?
5. What are the ethical considerations of recommending yoga as a treatment for clinical depression? How should it be integrated with standard care approaches?