A Critical Review of the Evidence for the Application of Yoga Therapy in Somatic Symptom Disorder and Related Disorders

Erfan Shakibi

Master’s Degree in Psychology

Holistic Yoga Teacher

Scientific Member of the International Institute of Holistic Yoga Therapy

Member of the Psychology Organization

www.ihyti.com

Abstract

Introduction

Somatic Symptom Disorders (SSDs) are a group of complex disorders at the boundary of medicine and mental health, characterized by distressing somatic symptoms and disproportionate cognitive, emotional, and behavioral responses to those symptoms. The high burden of illness, functional impairment, frequent use of health services, and the common comorbidity with anxiety and depression have increased the need to develop complementary, multidimensional interventions. Yoga therapy, as a mind–body intervention, has attracted attention in recent years because it combines physical exercises, breathing, relaxation, and attention to bodily experience.

The aim of this article is to critically review the available evidence on the application of yoga therapy in somatic symptom disorders, to examine the methodological quality of the studies, to explain possible mechanisms, and to determine future research priorities.

Direct studies on somatoform disorders, somatoform pain disorder, and medically unexplained physical symptoms, together with studies related to mind–body interventions and somatic symptom disorders, were reviewed and evaluated in terms of design type, sample size, assessment instruments, outcomes, and methodological limitations.

Findings

Direct evidence for yoga therapy is limited but promising. The studies by Sutar et al. (2016), Jha et al. (2021), Gulati et al. (2025), and Baboo et al. (2025) reported reductions in pain or in the severity of somatic symptoms. However, the early studies mainly had small sample sizes and single-group or feasibility designs. The study by Gulati et al. was the largest direct study available, with 70 participants, but participants were allocated according to their own preference and the study was not randomized. Therefore, the available evidence is not sufficient to establish the definitive efficacy of yoga therapy.

Therefore, yoga therapy should currently be regarded as a complementary and promising intervention in psychosomatic disorders, not as a replacement for standard treatments. Conducting randomized trials with an adequate sample size, an active control, a standardized protocol, assessment of clinical outcomes, and long-term follow-up is essential to determine its efficacy and mechanisms.

Keywords: yoga therapy; yoga; somatic symptom disorder; somatoform disorders; somatic symptoms; somatoform pain; mind–body interventions; psychosomatic.

Introduction

Somatic symptom disorders are one of the complex areas of psychosomatic medicine, in which the experience of somatic symptoms cannot be explained solely in terms of an organic disease or an independent psychological disorder. Newer approaches regard somatic symptoms as the product of a complex interaction among biological, psychological, and social factors, and emphasize the role of body perception, emotion, attention, cognition, and illness-related behaviors (Löwe et al., 2017; American Psychiatric Association, 2022). In DSM-5-TR, the diagnosis of somatic symptom disorder no longer depends on the “medical unexplainability” of symptoms. A person may simultaneously have a genuine physical illness and still meet the criteria for SSD; what matters is the presence of somatic symptoms and of excessive thoughts, feelings, or behaviors related to them (American Psychiatric Association, 2022). This conceptual change is of particular importance for yoga therapy research, because the simultaneous and undifferentiated use of terms such as SSD, somatoform disorder, and medically unexplained physical symptoms can lead to diagnostic heterogeneity in research samples.

In recent years, attention to mind–body interventions in the management of somatic symptoms has increased. Yoga is one such intervention which, unlike purely physical or purely psychological treatments, simultaneously emphasizes movement, breathing, attention, and emotion regulation. Despite the growth of yoga research on anxiety, depression, stress, and pain, specific evidence on SSD remains limited (Balasubramaniam et al., 2013).

Accordingly, the main question of this article is: How valid and reliable is the existing evidence on the efficacy of yoga therapy in somatic symptom disorders, and what types of research are needed to fill the existing gaps?

Diagnostic and Conceptual Considerations

One of the main problems of the existing literature is the use of different terms to describe similar but not entirely identical phenomena. In older studies, terms such as somatoform disorders, somatoform pain disorder, and medically unexplained symptoms were widely used, whereas DSM-5 replaced an important part of the previous structure with the concept of SSD (American Psychiatric Association, 2013).

ICD-11 has also introduced the concept of Bodily Distress Disorder (BDD), which overlaps conceptually with SSD but is not entirely equivalent to it. Consequently, future studies should precisely report the diagnosis used, the inclusion criteria, and their relationship to DSM-5-TR or ICD-11.

One consequence of this difference is the difficulty of directly comparing studies. For example, the study by Jha et al. examined patients with Somatoform Pain Disorder according to ICD-10, whereas future research may enroll patients according to DSM-5-TR and a diagnosis of SSD (Jha et al., 2021). Therefore, these two populations should not be assumed to be entirely identical without regard to diagnostic differences.

Why Yoga Therapy?

Yoga therapy is a heterogeneous set of interventions and, depending on the study, may include asanas, pranayama, relaxation, meditation, and body-awareness practices. Therefore, “yoga” should not be assumed to be a single, standardized treatment.

From a theoretical perspective, several pathways may play a role in the relationship between yoga therapy and somatic symptoms. First, breathing and relaxation practices may influence physiological arousal and the stress response. Second, body-awareness–based practices may change how a person attends to and interprets bodily sensations. Third, increased emotion regulation may reduce the cycle of anxiety, excessive attention to the body, and the intensification of symptom perception.

However, these mechanisms have not yet been tested directly and adequately in SSD.

Therefore, findings from physiological studies of yoga in healthy individuals should not be regarded as proof of the mechanism of treatment in SSD.

Research Background (Domestic and International)

Sutar et al. (2016) conducted one of the first dedicated experimental studies of yoga in somatoform disorders. The study began with 64 patients, and after a 12-week intervention, 34 completed the study. A reduction in pain severity was reported (Sutar et al., 2016).

The importance of this study lies in showing that a yoga-based program can be feasibly implemented in this population. However, the absence of a control group and the considerable attrition limit causal inference. Therefore, this study is important mainly as preliminary evidence of feasibility and hypothesis generation.

Rather than using a general yoga program, Jha et al. (2021) designed a dedicated module for somatoform pain disorder. Of 48 initial exercises, 34 remained in the final program after evaluation by experts, and the content validity index of the whole module was reported as 0.55. The program was then tested on 10 patients, and a significant reduction in pain was observed after two weeks (Jha et al., 2021).

This study is of great importance in terms of intervention development, because one of the main problems of yoga research is the lack of standardization in intervention content. However, the very small sample size and the absence of a control group do not allow the specific effect of the program to be determined.

Gulati et al. (2025) presented the largest controlled study among the existing reviewed studies. In this study, 70 individuals with somatoform pain disorder were enrolled and, according to their own preference, were assigned either to a yoga plus standard treatment group (38 participants) or to a wait-list control plus standard treatment group (32 participants). Therefore, the study was not randomized, although the outcome assessor was blinded (Gulati et al., 2025).

The intervention lasted 24 weeks, and pain was assessed with the VAS at baseline and at 2, 6, 12, and 24 weeks. Secondary outcomes included anxiety, depression, somatic symptoms, disability, and quality of life. Analyses were performed using the Friedman test and a linear mixed model (Gulati et al., 2025).

At the end of 24 weeks, pain was significantly better in the yoga group (P<0.001). In addition, at week 12, significant improvements in anxiety (P<0.01), depression (P<0.05), somatic symptoms (P<0.01), and physical health–related quality of life (P<0.01) were reported in favor of the yoga group (Gulati et al., 2025).

These results support a potentially positive effect, but they should be interpreted with caution. Because patients entered the groups according to their own preference, selection bias and possible baseline differences between the groups may explain part of the observed difference. In addition, a wait-list control group cannot control for the effects of therapist attention, treatment expectancy, and group interaction.

Therefore, this study should be regarded as a controlled study with promising evidence, not as a definitive RCT.

Baboo et al. (2025) developed a yoga therapy module for medically unexplained physical symptoms. Of 47 initial exercises, 34 remained in the final version, and 32 yoga experts participated in the content validation process. The CVR of the exercises exceeded 0.37, and the overall CVI was reported as 0.59 (Baboo et al., 2025).

In the feasibility phase, 12 patients received the intervention for one month, and the PHQ-15 was assessed before and after treatment. A significant reduction in symptom severity was reported; however, the authors emphasized that, because of the small sample size and the pilot nature of the study, conducting an RCT is necessary (Baboo et al., 2025).

This study is an important advance over previous studies, because it shows that the path of yoga therapy research is moving from “the use of general yoga” toward the design and standardization of a dedicated intervention.

In Iran, direct evidence on yoga therapy and SSD is very limited. One related study is the research by Zargar et al. (2021) on MBSR in patients with SSD. This study was not a yoga therapy study, but it showed that a mindfulness intervention, alongside pharmacotherapy, can improve the psychological and somatic symptoms of SSD patients.

Since MBSR and Yoga Therapy theoretically fall within the domain of mind–body interventions, this study can be regarded as indirect Iranian evidence; however, it should not be included among the direct evidence as a study of the efficacy of yoga.

This research gap in Iran is of great importance, because conducting a standard RCT in an Iranian population could be one of the first direct studies with the potential for international publication.

Methodological Problems of the Existing Literature

Sample Size

Most direct studies have small samples. Jha had only 10 patients, and Baboo likewise examined 12 patients in the feasibility phase. Such sample sizes are insufficient for accurately estimating effect size and for examining treatment moderators.

Lack of Randomization

The most important controlled study available, that of Gulati et al., was grouped according to participants’ preference. Therefore, future studies should use random allocation.

Lack of an Active Control

A wait-list cannot control for the nonspecific effects of treatment. For example, part of the improvement may be due to increased social interaction, therapist attention, patient expectancy, or the regular structure of the sessions.

Diagnostic Heterogeneity

Directly comparing SSD, MUPS, somatoform pain disorder, and BDD without regard to the diagnostic system reduces the validity of a future meta-analysis.

Intervention Heterogeneity

It is not clear which component of yoga therapy is effective: asana, pranayama, relaxation, meditation, or a combination of them.

Predominantly Self-Reported Outcomes

A considerable proportion of studies rely on the VAS and self-report questionnaires. A 2024 review of MUPS instruments also showed that, although many instruments exist, the cross-cultural validity of many of them is still limited (Baboo et al., 2024).

Future Research Suggestions

This section should be one of the strongest parts of the final version of the article, because the gap in the literature creates precisely this research opportunity.

Conducting a Multicenter RCT

The most important priority is to conduct a multicenter randomized controlled trial. Such a study should have at least three treatment arms:

Group one: Standard treatment

Group two: Standard treatment + yoga therapy

Group three: Standard treatment + active control

The active control may include light stretching exercises, health education, or physical activity of similar intensity.

This design makes it possible to determine whether the effect of yoga results from yoga-specific content or merely from increased physical activity and therapeutic attention.

Full Standardization of Yoga Therapy

Future studies should not merely write “patients received yoga.” The following items must be specified:

• Number of sessions
• Duration of each session
• Intensity of practice
• Type of asanas
• Type of pranayama
• Duration of relaxation
• Duration of meditation
• Home practice
• Level of adherence
• Therapist training

The modules developed by Jha and Baboo can be a suitable starting point for this standardization.

Using a DSM-5-TR or ICD-11 Diagnosis

Future research should precisely specify the diagnostic criterion and should not use the general term “psychosomatic illness.”

It is suggested that the main sample be defined on the basis of DSM-5-TR Somatic Symptom Disorder and, where possible, that the ICD-11 diagnosis also be examined secondarily. This increases the possibility of international comparison of results.

Calculating Sample Size Based on Effect Size

Sample size should not be determined based on the number of participants in previous studies. A pilot study should first be conducted, and the effect size, variance, and dropout rate should be obtained. A power analysis should then be performed for the primary outcome.

For example, if the aim is to examine the interaction between group × time, the sample size should be calculated based on a repeated-measures model or a mixed-effects model.

It is also better for researchers to consider an attrition rate of 15 to 25 percent in the initial design.

Using Linear Mixed-Effects Models

Instead of running several separate t-tests or ANOVAs, using linear mixed-effects models is more appropriate, because:

• It models longitudinal data better;
• It is more flexible with missing observations;
• It examines the effects of time and group simultaneously;
• It directly tests the interaction between group and time.

The primary analysis should be based on intention-to-treat, and per-protocol analysis should also be presented alongside it as a sensitivity analysis.

Reporting Effect Size and Confidence Interval

One of the common weaknesses of interventional research is that only the P-value is reported.

Future studies should report at least the following:

• Mean Difference;
• Standardized Mean Difference;
• Cohen’s d or Hedges’ g;
• 95% CI;
• P-value;
• Minimal Clinically Important Difference.

This is essential to determine whether “statistical improvement” is truly also clinically meaningful for the patient.

Examining Treatment Mechanisms

Future research should not merely ask:

(Does yoga reduce symptoms?)

but should ask:

(Through what pathway does yoga reduce symptoms?)

For example, it can be examined whether the following pathway occurs or not:

Reduction in health anxiety → reduction in catastrophizing → increase in body awareness → reduction in symptom severity

Mediation analysis can be used for this purpose.

Examining the Role of HRV

HRV can be one of the interesting physiological indicators in future research. If yoga therapy truly produces part of its effect through the regulation of autonomic function, changes in HRV may be related to changes in symptom severity.

Therefore, the following model can be tested:

Yoga → HRV change → reduction in somatic symptoms

But this relationship must be tested empirically and should not be presented in advance as a proven mechanism.

Long-Term Follow-Up

One of the most important shortcomings of the existing literature is the lack of sufficient information about the durability of the effect.

It is suggested that assessments be conducted at:

• Baseline;
• End of treatment;
• 3 months;
• 6 months;
• 12 months.

This will clarify whether the patient has truly acquired self-regulation skills or whether the effect remains only during the treatment sessions.

Examining Adherence

Unlike many medications, yoga requires the active participation of the patient.

Therefore, it should be specified:

• How many sessions did the patient attend?
• How many minutes per week did the patient practice?
• Did the patient carry out the home practice?
• Is the amount of practice related to the degree of improvement?

In that case, the dose–response relationship can be examined.

Comparing Yoga With CBT

Since CBT has far stronger research support in SSD, future research should directly compare yoga with CBT.

Three important questions can be examined:

• Is yoga weaker than CBT?
• Does yoga have a similar effect?
• Is Yoga + CBT more effective than either alone?

The third question is very important clinically.

Designing a Combined Yoga + CBT Treatment

A very promising path may be the combination of these two interventions:

CBT → Modification of cognitive interpretations and illness behaviors

Yoga → Regulation of the body, breathing, attention, and arousal

This model may be suitable for patients who have both severe preoccupation with symptoms and high bodily tension.

Identifying Responders and Non-Responders

Yoga may not be equally effective for all SSD patients.

Future research can examine whether treatment response is related to variables such as the following, or not:

• Gender;
• Age;
• Duration of illness;
• Baseline symptom severity;
• Health anxiety;
• Depression;
• Alexithymia;
• Catastrophizing;
• Level of physical activity.

This moves toward personalized medicine and the selection of the appropriate patient for yoga therapy.

Personalizing Yoga Therapy

Probably not all SSD patients benefit from yoga to the same extent. Future research should specify which patients respond more.

Potential variables include: baseline symptom severity; health anxiety; depression; catastrophizing; alexithymia; duration of illness; level of physical activity; sleep quality; gender; age.

This path can steer yoga therapy research from one-size-fits-all toward personalized intervention.

A Specific Proposal for a Future Iranian Study

Based on the existing gap, one of the strongest research designs that could be implemented in Iran might be as follows:

Title

The Efficacy of Yoga Therapy Added to Standard Treatment in Patients With Somatic Symptom Disorder: A Randomized Controlled Trial Examining the Role of Emotion Regulation and Body Awareness

Design

Three-arm RCT, assessor-blinded, with 12-month follow-up.

Sample

The minimum sample size should be determined on the basis of power analysis, not on the basis of the samples of previous studies.

Groups

• Standard treatment
• Standard treatment + yoga
• Standard treatment + active control

Primary Outcome

PHQ-15 or a valid instrument appropriate to the diagnosis.

Secondary Outcomes

• SSD severity
• Anxiety
• Depression
• Health anxiety
• Alexithymia
• Catastrophizing
• Body awareness
• Quality of life
• Functional disability
• Healthcare utilization

Physiological Indicator

HRV.

Analysis

Linear mixed-effects model + intention-to-treat + effect size + 95% CI.

If rigorously implemented, this study could also fill an important gap in the global literature, because most of the current direct evidence has come from India, and direct evidence from Iran is very limited.

Final Conclusion

The available evidence indicates that yoga therapy in the field of somatic symptom disorders is a promising but still unproven intervention. Existing studies, particularly the study by Gulati et al., have shown positive results regarding pain, somatic symptoms, anxiety, depression, and some dimensions of quality of life; however, the open-label design and the lack of random allocation limit the causal inference of these findings.

On the other hand, the studies by Jha and Baboo show that the field of yoga therapy is moving toward the design of dedicated and standardized interventions for somatic symptoms. This development is of great importance for future research, because one of the main problems of yoga research has been the heterogeneity of intervention content.

Therefore, based on current evidence, yoga therapy cannot be regarded as a replacement for standard SSD treatments. Its most appropriate current position is that of a complementary intervention within a biopsychosocial model.

Most importantly, the main research gap is no longer “Might yoga be useful?”; rather, the next scientific question should be:

For which patients, with which protocol, at what dose, through which psychological or physiological pathway, and in comparison with which treatment does yoga therapy have the greatest effect?

Answering this question requires large, standardized, multicenter RCTs with long-term follow-up. Conducting such studies, particularly in Iran, could move the field from the stage of preliminary evidence toward clinically reliable evidence.

References

Direct Yoga Therapy Sources

Baboo, A. G. K., Babu, N., Rawat, N., Anwar, W., Purohit, S., & Ranjan, P. (2025). Development, validation, and feasibility of a yoga-based module for medically unexplained physical symptoms. International Journal of Yoga, 18(3), 314–320. https://doi.org/10.4103/ijoy.ijoy_240_24

Gulati, K., Gunasekaran, D. M., Bhargav, H., Bhaskarapillai, B., Nandakumar, D. N., Varambally, S., Gangadhar, B. N., & Desai, G. (2025). The efficacy of add-on yoga intervention in somatoform pain disorders: An open-label controlled trial. Indian Journal of Psychiatry, 67(3), 316–322. https://doi.org/10.4103/indianjpsychiatry.indianjpsychiatry_932_24

Jha, M., Dumbala, S., Gulati, K., Bhargav, H., Arasappa, R., Varambally, S., et al. (2021). Yoga module for somatoform pain disorders: Development, content validation, and feasibility testing. International Journal of Yoga, 14(3), 206–212. https://doi.org/10.4103/ijoy.IJOY_125_20

Sutar, R., Desai, G., Varambally, S., & Gangadhar, B. N. (2016). Yoga-based intervention in patients with somatoform disorders: An open label trial. International Review of Psychiatry, 28(3), 309–315. https://doi.org/10.1080/09540261.2016.1188785

Sources Related to MUPS and Mind–Body Interventions

Kashyap, A., Chopra, S., Ranjan, P., Sarkar, S., Poorna, A., & Baitha, U. (2020). Yoga therapy for medically unexplained physical symptoms. Advances in Mind Body Medicine, 34(1), 17–21.

Zargar, F., Rahafrouz, L., & Tarrahi, M. J. (2021). Effect of mindfulness-based stress reduction program on psychological symptoms, quality of life, and symptom severity in patients with somatic symptom disorder. Advanced Biomedical Research, 10, 9. https://doi.org/10.4103/abr.abr_111_19

Rani, S., Singh, K., & Malhotra, S. (2012). Six-month trial of Yoga Nidra in menstrual disorder patients: Effects on somatoform symptoms. Indian Journal of Physiology and Pharmacology, 56 / related indexed publication. https://doi.org/10.4103/0972-6748.102489

Methodological Sources

Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., et al. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ, 372, n71. https://doi.org/10.1136/bmj.n71

Sterne, J. A. C., Hernán, M. A., Reeves, B. C., Savović, J., Berkman, N. D., Viswanathan, M., et al. (2016). ROBINS-I: A tool for assessing risk of bias in non-randomised studies of interventions. BMJ, 355, i4919. https://doi.org/10.1136/bmj.i4919

Sterne, J. A. C., Savović, J., Page, M. J., Elbers, R. G., Blencowe, N. S., Boutron, I., et al. (2019). RoB 2: A revised tool for assessing risk of bias in randomised trials. BMJ, 366, l4898. https://doi.org/10.1136/bmj.l4898

Rief, W., Burton, C., Frostholm, L., Henningsen, P., Kleinstäuber, M., Kop, W. J., et al. (2017). Core outcome domains for clinical trials on somatic symptom disorder, bodily distress disorder, and functional somatic syndromes: Recommendations from the European Network on Somatic Symptom Disorders. Psychosomatic Medicine, 79(9), 1008–1015. https://doi.org/10.1097/PSY.0000000000000502

Diagnostic Sources

American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.; DSM-5-TR). American Psychiatric Association Publishing.

Toussaint, A., Löwe, B., Brähler, E., & Jordan, P. (2017). The Somatic Symptom Disorder–B Criteria Scale (SSD-12): Factorial structure, validity and population-based norms. Journal of Psychosomatic Research, 97, 9–17. https://doi.org/10.1016/j.jpsychores.2017.03.017