The yogic idea of mental silence implies first, that taming of the mind is the key to successful personal development and second, that the untamed mind is a fundamental factor in the development of disease. These ancient ideas are reflected in modern scientific evidence which demonstrates the deleterious impact of stress and negative affect (emotion/mood) and the constructive impact of positive moods on health. In fact this evidence forms the basis of modern theories such as the bio-psychosocial model of health, positive psychology (and specifically the ideas of mental hygiene, flow state, peak experience and plateau experience) and the religion–health connection (to be discussed later). It represents a development of the idea of psychosomatic disease postulated in the 1970s, psychoneuro-immunology and mind-body medicine.

For more discussion on the aims of yoga check Dr Ramesh Manocha’s site.


The rise of Western “pop culture” and “alternative lifestyles” in the 1960s, was a crucial social change that led many Western consumers to dabble with spiritual ideas and practices, especially meditation. Symbolising this development was the Beatles’ much-publicised trip to a meditation retreat in Rishikesh, India. The fact that the Beatles left the retreat in disappointment and acrimony not long after their arrival, serves to illustrate the other side of this social phenomenon; that the ancient tradition has been misused by entrepreneurs and cultic organisations who have exploited Westerners’ naiveté and ignorance of the historical, philosophical and cultural context from which meditation emerged.


This data emerged from a small trial of Sahaja Yoga meditation (SYM) reported by Rai in New Delhi, India. In a randomised controlled trial, 18 female sufferers of severe asthma were allocated either to a SYM or a waiting list/standard treatment control group. The study was not published in the peer-reviewed literature, but nevertheless the study warrants attention.  In 9 patients randomised to the intervention group, the FEV1/FVC ratio increased from 48% at baseline to 66% at the conclusion of the 4-month intervention. Over the same period the spirometric ratio did not change in 9 control participants (p < 0.001). Participants in the intervention group had an average of 5.8 “acute attacks” during the treatment period, compared with 12.9 “acute attacks” over the same period in the controls (p < 0.001).

More information about asthma can be found at Dr Ramesh Manocha’s blog.


Although many of meditations adverse effects reported in literature are anecdotal cases studies, incidental findings or unexpected outcomes it is clear that meditation is not a universally benign intervention and that it can be associated with both serious and non-serious adverse reactions. Some studies, such as those of Otis (1984) and Persinger (1993, 1992), suggest a dose response relationship whereas others, such as that of Xu (1994), suggest an unpredictable idiosyncratic effect.

For more information regarding future research that needs to investigate the adverse effects of meditation, check Dr Ramesh Manocha’s blog.


The direct impact of negative thoughts and emotions on immunological function seems to be reasonably well documented and, since many Psychoneuroimmunology (PNI) phenomena seem to be mediated by negative affect, rather than situational “stress”, strategies that directly modify this factor may manifest greater benefits. While relaxation orientated meditation most likely acts to reduce the impact of stress that are mediated by neuroendocrine mechanisms such as the sympathoadrenal and hypothalamicpituitary axes, so too do other strategies that reduce physiological arousal. It might be argued that since mental silence approaches to meditation aim to not only reduce physiological arousal but also mitigate negative rumination and affect this may be one reason why it seems to be associated with a specific effect.

For more information on the effect a negative mood can have on the immune system, check out Dr Ramesh Manocha’s article on Psychoneuroimmunology.


A reduction of autonomic arousal leads to diversion of blood flow to the viscera and away from the skeletal muscle of the body. Accordingly this leads to increased blood flow to the surface of glabrous skin and thereby an increase in palmar skin temperature. Sahaja Yoga meditation practitioners appear to perform exactly the same overt task as conventional meditators since, like conventional meditators, they appear to sit quietly. If however the physiological changes that occur are different then it would suggest that despite overt similarities, the biological events are quite different. This would suggest that Sahaja Yoga meditation (and hence presumably the mental silence experience) is physiologically atypical. The mental silence experience may be associated with a unique spectrum of physiological activity.

A detailed summary of the physiology of skin temperature can be found at Dr Ramesh Manocha’s website.


The mental silence experience clearly warrants further investigation. Needless to say, it would be ideal if this research was carried out by those without a financial, emotional or reputational stake in any such research. Experience however suggests that for the foreseeable future it will be meditation enthusiasts who will drive this field of exploration. In view of the promising findings future randomised controlled trials should include even more rigorous adhesion to CONSORT guidelines for clinical trials. Further, self report outcomes should be additionally complemented by objective biological outcomes.

Further directions of future research on meditation can be found at Dr Ramesh Manocha’s website.


Xu (1994) described and discussed the adverse effects of Qigong, which has been described as both a therapeutic practice as well as the “Chinese equivalent of Indian meditation”. The clinical consequences of inappropriate use of this technique has been described as the “Qigong deviation syndrome”, which has become a diagnostic term “now used widely in China” and is associated with a range of somatic and psychological disturbances. The commonest somatic symptoms include headaches, insomnia and discomfort caused by abdominal distension, while common psychological symptoms include anxiety, agitation and depression. Extreme psychological symptoms can include uncontrollable behaviours, psychosis and suicide.

For further reading regarding adverse effects arising from the use of Qigong, check Dr Ramesh Manocha’s blog.


Goleman (1996) proposed that meditative styles might be classified into two types, Mindfulness and concentrative, depending on how attention is directed during meditation. Andresen (2000) meanwhile suggested that these two categories might be better understood as two poles on a continuum upon which most other meditative techniques can be positioned. On the other hand, Cahn (2006) acknowledged the limitations of this taxonomy and suggests that a different way of categorising techniques may be according to the underlying experience that the various techniques aim to elicit.

For further reading regarding the taxonomy of meditation, check Dr Ramesh Manocha’s Website.