Yogic intervention for mental disorders

An upsurge in research has been reported in the field of non-pharmacological intervention in managing mental disorders. Yogic intervention as a non-pharmacological approach has been used in several research reports. The research reports published in the current issue provides significant direction in the area of depression, schizophrenia and other mental disorders. There is an attempt to develop generic models and validate the same. Specific steps are required to develop the support for developing consensus documents. There is also a need to develop a strong evidence base in the direction of clinical application and focus on basic research. There is need to develop conceptual and heuristic models for explaining the effect of yoga.

During recent years, there have been a number of publications of several research reports that document the effectiveness of yoga in mental disorders. Specifically, the last decade has witnessed several studies aimed at collecting objective data to provide the basis of use of yoga as intervention procedure.[1]

Yogic procedures have been used for improving general well-being for ages in India. However, collecting evidence for scientific research has been a recent phenomenon. When we attempt to trace the trends in research in yoga and medicine during the last 50 years in India, from the conceptual point of view, it suggests how the research link between yoga and mental disorders has evolved. To begin with the research was only limited to investigating reduction of stress and/or improvement in cardiorespiratory fitness. For several years, the use of yoga as stress antidote has prevailed among researchers. It brought three disciplines closer namely psychology, yoga and medicine. Physiologists joined the research program later and started verifying the so called claims of yoga.[2,3] The inclusion of physiological parameters, gave a boost and platform for doing research in studying the effectiveness of yoga in certain stress related disorders such as diabetes mellitus, hypertension etc., Initially, the research focused on physiological parameters at All India Institute of Medical Sciences while National Institute of Mental Health and Neurosciences (NIMHANS) started working on cognitive parameters and psychiatric disorders.[3] Indeed the entry of yogic intervention to neurological and psychiatric disorder was not without resistance. The author himself, experienced resistance when he carried out the first study in epilepsy and attempted to measure clinic-electroencephalographic and neuropsychological evaluation in patients.[4] Except the early reports of Vahia et al. in early 70s,[5] the role of yoga was hardly tried in depression as it was considered to be “mind calming procedure.” Probably, people believed that it might cause depression itself. Contrary to this belief, the researchers from NIMHANS showed positive effects of Sudarshan Kriya Yoga on executive brain functions and extended the research to improve depression.[6] The research in the field of neuropsychiatric illness was rightly picked up by NIMHANS and Swami Vivekananda Yoga Anusandhana Samasthana and Jawaharlal Institute of Postgraduate Medical Education and Research. They have been publishing work in yoga and mental disorders and other institutions since then.[3,7]

THE FOCUS IN THE CURRENT ISSUE

The current issue of Indian Journal of Psychiatry has brought out a dedicated supplement to address the issue of yogic intervention in mental disorders. There are 14 articles published in the current issue. It is an encouraging documentation that reflects contemporary thought in the field of yogic intervention in mental disorders. All these studies presented here can be grouped in three categories, namely- studies on depression, studies on functional psychotic disorders and studies addressing related issues in geriatrics population. Indeed, there is some degree of overlap in research areas of these studies.

Of all the groups, the group on depression presents large number of significant findings. There are six studies included in this group. The study by Varambally et al. (2013) provides reconfirmation of the decreased levels of brain derived neurotrophic factors (BDNF) in patients of depression. Thirthali et al. (2013) report increase in cortisol levels in the patients of depression. Naveen, Thirthalli and Rao et al. (2013) further provide evidence that the yogic intervention is likely to increase BDNF serum levels in patients of depression. These studies bring biochemical basis for explaining the effect of yoga in depression. Three articles provide practical directions to the use of yogic intervention in patients of depression (Gangadhar et al., 2013; Naveen, Rao and Vishal et al., 2013; Umadevi et al., 2013). Other later studies are very important for developing standard guidelines.

There are three studies fall in the group of studies on functional psychotic disorders. Two studies address the issue related to schizophrenia. The third study addresses attention deficit hyperactivity disorder (ADHD). The study by Jayram et al. (2013) provides strong biochemical evidence that yogic intervention resulted in the elevation in plasma oxytocin levels in schizophrenics. This evidence along with other such findings supports the use of yoga as one of the tools for management of schizophrenia. Justifiably, Manjunath et al. (2013) have given further practical direction in their study. They have reported the use of yogic intervention as add-on modality for schizophrenia. Undoubtedly, it is one of the most difficult areas from the point of view of administration, acceptance and management. The other study in this group addresses the commonly occurring ADHD where the feasibility issue has been addressed (Hariprasad, Arasappa and Varambally et al., 2013).

In the third group, there are 4 studies addressing very important emerging issue of geriatric psychiatry. Hariprasad, Varambally and Sivakumar et al. (2013) used magnetic resonance imaging scans and showed that hippocampal volume increases after 6 months of yoga practice by elderly group. This study although preliminary is very important basic research in the field of yogic intervention. The other two research articles address the issues concerning sleep related problems (Hariprasad, Sivakumar and Koparde et al., 2013) and cognitive functions (Hariprasad, Koparde, Sivakumar et al., 2013). Validation of yogic intervention protocol by Hariprasad, Varambally, Sivakumar (2013) certainly paves the way for use of yogic intervention in the geriatric population.

One study reports data on knowledge, aptitude and practice among epileptics who underwent yogic intervention (Naveen, Sinha and Girish et al., 2013).

The research work presented in this issue is commendable in the field of yogic intervention in mental disorders. The studies present two main directions. Firstly, the researchers report hard core evidence that explains the mechanismal aspects. Secondly, some studies have focused on validation of intervention protocols both generic and specific ones. The yogic intervention studies do encounter the methodical problems and several confounding factors. Of course, there are some weaknesses in certain studies, which have been amply explained in the respective articles. In spite of these limitations, the academic gains are much larger.

DEVELOPING CONCEPTUAL FRAMEWORKS: THE FUTURISTIC MODELS

Theoretically, the research programs are guided by developing a working conceptual framework for the problem. These conceptual frameworks may take the shape of simple hypotheses or complex models. The most simplistic yet effective model to explain yogic effect has been the concept of “the relaxation response” propounded by Herbert Benson of Harvard Medical School. Over the years, several other models/mechanism have been put forth to explain the effect of yogic intervention.

Bio-psycho-social model is good for explaining the causation of psychosomatic illness. This is insufficient to explain the mechanism of effect of yoga at physiological, neurochemical or cellular level. There is a need for developing utilitarian model(s) to explain the effect of yoga in mental disorders. The psychiatric illness is multi-dimensional and may involve several mechanisms in varying proportions. Therefore, a quasi-distinction can be made in various models for the purpose of explaining the effect of yoga in mental disorders.

There are several conceptual frameworks/models which have been reported in the literature. Broadly speaking they focus on autonomic mechanisms,[8] neurophysiologic mechanisms,[9] neurochemical mechanisms,[1] cognitive mechanism[9] and spiritual mechanisms.

“Autonomic models” appear very useful for explaining cardiorespiratory effects and stress related pathophysiology (stress predominant effects) such as diabetes, hypertension, myocardial infarctions, etc.[8] The neurophysiologic models are useful for explaining the role of yogic intervention in neurologic disorders such as epilepsy (non-stress predominant effects).[9] For psychiatric disorders, it appears that neurochemical models would work better. Some evidences and direction to this effect have been forwarded by Balasubramaniam et al. (2013).[1]

In my opinion, a comprehensive model based on control systems would work better for mental disorders. Let me explain why systems control theory should be used here. During illness, the set points (biochemical/physiological/psychological) get reset at pathologic levels. The yogic intervention might restore to a different level, supposed to be normal setting. The restoring of set point(s) might be operative as long as yogic intervention is effective. The operational aspects of set point such as sensitivity and intervention are best explained by systems theory. Further, there is a greater likelihood of having multiple hierarchal set points since the yogic intervention certainly influences at multiple levels – biochemical, physiological, psychological and spiritual settings both in patients and healthy individuals. Therefore, the model needs to be comprehensive. There is a need to develop such heuristic models. The volume of work presented in this special issue provides us sufficient direction to propose/develop models/conceptual framework for future research. I would encourage endeavors in this direction.

THE SCOPE AND STRATEGY FOR FUTURE DEVELOPMENTS

The latest version of Diagnostic and Statistical Manual of Mental Disorders (version 5, DSM-V) defines several so-called normal psychological aberrations as disease states. There has been much hue and cry among experts about defining limits of sub-normality. However, sooner or later it is likely to be accepted. Although our country sticks to World Health Organization prescribed International Classification of Diseases-10 (ICD-10) (1993) for this purpose, which is several years old. Therefore, in the current scenario the definition of sub-normality is going to be narrower and narrower. Thus, the yogic intervention is going to be all the more useful and practical in the face of such developments. Therefore, it is surmised that yogic intervention is going to be therapy of choice for both scientific and practical reasons for larger masses in future.

Another important issue to be addressed in this field is to involve rigorous research methodology and provide research training and support to researchers. Several studies involving yogic intervention fall short on objective scrutiny, especially when we use standard criteria of clinical trials.[10,11] The web search by using phrase “yoga” and “meditation” in National Institute of Health, USA web repository shows 73 entries, out of which 3 were found to be located in India. Coincidently, all these three studies address the issue related to mental disorders (ADHD, tension headaches and behavioral problems related to human immunodeficiency virus). Surprisingly, a similar number i.e., 73 of clinical trials are currently registered with Indian Council of Medical Research (ICMR) (search by phrase “yoga” and “meditation”). Out of these 73 trials in yoga, eight clinical trials address issues related to mental function/conditions. Seeing this data, we feel that there is a large scope of research in this field in our country. Moreover, there is further need to strengthen research capacity. Therefore, I would recommend the following steps by academic associations/research councils and individuals:

1. Development of specific research training program for psychologists/physiologists/psychiatrists/neurologists/yoga experts to conduct such studies

2. Development of consensus guidelines/consensus statements for use of yogic intervention in psychiatric illness

3. Development of consensus guidelines/consensus statements for use of yogic research in neurophysiology and neuropsychology

4. Publication of meta-analyses for specific mental disorders

5. Development of official research alliances/collaboration among related departments to conduct interdisciplinary research in this filed.

While planning a study on yoga a large number of confounding factors needs to be tackled. It will be advisable to be more rigorous in designing the intervention studies. Adhering to standard classifications (ICD-10 or DSM-IV), standard method and appropriate research designs would be useful to enlarge the evidence base in the field.

There are several issues, which can be addressed by researchers in the future. For example, how much spiritual component is responsible for the yogic effect especially in functional disorders? Specifically, in my opinion yogic intervention may be effective in reducing symptoms and signs in several mental disorders. However, there is a need to quantify the specific value in terms of their effectiveness by using randomized clinical trials. Besides mental disorders, the field of opioid dependent syndrome (ODS) and several other problems with drug abuse is still open in spite of earlier documentation. One such study to examine the effect of yoga is currently being carried out at Yale University, USA where the primary outcome measures are pain and drug abuse reduction.[12] It will be worth to plan a randomized controlled trial study with the purpose of reducing the withdrawal symptoms after detoxification in ODS patients and correlating with biochemical parameters. The field of use of yoga as add-on therapy is wide open in the area of pharmacotherapeutics. In a recent meta-analysis, Cabral et al. (2011) concluded that yoga may help in reducing the metabolic side-effect of pharmacologic therapies.[13]

CONCLUSION

The present special supplement on yogic intervention of functional psychiatric disorders is landmark documentation in the field. A significant direction has been provided by the group of studies in the area of depression, schizophrenia and other mental disorders. Some studies support in the direction of developing specific and generic models and to validate the same. A large number of registered clinical trials with ICMR are evidence in this direction. Certainly, it is desirable direction for research in this area and the environment is friendly for pursuing such research. However, there is a need to develop a strong evidence base in the direction of clinical application and focus on basic research. There is an imminent need of developing appropriate heuristic models, which can help the field of yogic intervention for functional psychotic disorders.