Psychosomatic Associations Between Thinking Patterns and Parkinson’s Disease from a Yoga Philosophy Perspective:

Psychosomatic Associations Between Thinking Patterns and Parkinson’s Disease from a Yoga Philosophy Perspective:

A New Zealand Cross-Sectional Study

Sridhar Maddela, MHSc, C-IAYT, E-RYT 500,1  Stephen Buetow, MA (Hons), PhD1

 Department of General Practice and Primary Health Care, School of Population Health, University of Auckland, New Zealand.



When investigating the etiology of diseases, epidemiological observational studies traditionally deemphasize psychoso- matic associations. Exploring cognitive behavior provides an insight into how psychosomatic associations affect dis- ease. Yoga philosophy identifies the kleshas (mental afflic- tions) of ignorance, ego, desire, hatred, and fear of death with disease. This is because individuals’ perceptions and beliefs generate and reflect streams of thought that may shape their behavior and manifest as, or predispose them to, particular disease(s). The present study takes a yogic philo- sophical perspective to help elucidate unexplored associa- tions between thinking about different aspects of life and the severity of Parkinson’s disease (PD). The study involved a cross-sectional sample survey. Parkinson’s New Zealand selected a random sample of 990 of its members. A self- completed questionnaire was sent to them. It asked ques- tions about how often, over the previous 4 weeks, they had thought about 18 aspects of life commonly associated with the kleshas. A completed questionnaire was returned by 319 people (32%). Respondents thought most about family (87%), health (64%), rest and sleep (57%), food (53%), and the future (52%). They reported thinking least about work (48%), sex (45%), death (42%), and being virtuous (39%). A weak, but hypothesized positive, association (r = 0.2, p < 0.000) was detected between PD severity and thinking about death. The study could not determine whether thinking about death was (1) a cause or conse- quence of PD severity, and (2) a premorbid behavior. However, the possibility that stress associated with thinking about death accelerates PD progression is consistent with yoga philosophy and with neurophysiological mechanisms associated with the psychosomatic connections. The find- ings are worthy of future testing. A retrospective cohort study and qualitative research could deepen understanding about the role of kleshas in PD. Maddela & Buetow. Int J Yoga Therapy 2019(29). doi: 10.17761/D-17-2019-00031.

 Keywords: Parkinson’s disease, yoga philosophy, kleshas (mental afflictions), psychosomatic association


Parkinson’s disease (PD) is the most common neurodegen- erative disease after Alzheimer’s disease.1 It produces consid- erable disability for people living with the condition, their families, and the community. With no current cure or cer- tain cause, it is important to be open to different perspec- tives on why some people develop PD and why their disease severity worsens at different rates. Potentially relevant per- spectives include yoga philosophy (YP), which considers cognitive means of acquiring disease (Patanjali’s Yoga Sutra, Chapter 2, Verse 3).2–5 Both individual perceptions and soci- etal influences are assumed to integrate sensory and cogni- tive stimuli and the physiological response that follows.6–8 As the role of thinking and the nature of thought behavior in PD have not been studied before, investigation of how individuals’ thinking patterns may contribute to the devel- opment and neuroprogression of this disease is warranted.

According to YP, as mentioned in the Yoga Sutras (YS),2,4,5,9 individuals’ perceptions and beliefs generate reflec- tive streams of thought (1.4–1.11). Therefore, YS defines yoga as restraining the mental perceptions and beliefs that persist as the cognitive behavior of an individual (1.2).2 YP also states that diseases originate as mental revisions of cog- nitive behavior and cause a cascade of physical responses (2.15).10 These responses seek to maintain relatively stable physiology to accommodate the mental ebb and flow aris- ing from changes in the environment of the individual. This physiological wisdom was termed homeostasis by physiolo- gist Walter Cannon.11   Homeostatic mechanisms operate by


International Journal of Yoga Therapy — No. 29 (2019)

up- and down-regulating the physiology of organ systems in response to the individual’s perceptions. Homeostatic regu- lations over time may cause cells to adapt, leading to the manifestation of chronic noncommunicable diseases like PD.

YP further states that kleshas (mental afflictions)— avidya (ignorance), asmita (ego), raga (desire), dvesha (hatred), and abhinivesha (fear of death/wanting to live)— cause suffering/disease by acting as long-term stressors (YS 2.3).2,12 These kleshas are cognitive aspects of oneself that can be detrimental to health.13,14 Interpreting YS, Swami Satyananda Saraswati15 describes the five kleshas as outlined below.

Stress manifests as perpetual desires that can cause suf- fering and disease.16 For example, desiring material indul- gences causes mental stress. An individual’s suffering and diseases have their origin in avidya. This first affliction refers to the ignorance that arises when the soul descends into matter and forgets its divine origin (2.5). The second afflic- tion, asmita (2.6), results. It leads to separation, the cause of false identification, and in turn operates through the mech- anism of the third and fourth afflictions (2.7–2.8), raga and dvesha. Here, one experiences mind and body (thoughts, words, and actions), which operate interdependently and dualistically. Within YP, attachment and hatred condition the terrain of human existence, as they are the kleshas with which people mostly associate.9 Although all of the kleshas stimulate cognitive thinking, it appears that desire and hatred, strongly associated with the brain’s reward system, galvanize cognition the most. Desire, a sense of attraction, is opposite hatred, which activates a sense of rejection. The fifth affliction is abhinivesha (2.9), or the desire (of the body) to live, which is associated with fear of dying (losing existence).17 This affliction defines the basic obstacle to reversing the attachment we have to the “life” of structure, whose dissolution is experienced as death.

The process of imbalance and ill health results from the disunification of the mind and body.18 Not understanding the purpose and four aims of life—artha (material wealth), kama (emotional fulfillment), dharma (duty), and moksha (liberation)—and their associations with afflictions leads to separation.14 The affliction of ignorance is characterized by lack of self-awareness, which may result from identifying oneself with failure in the quest for materialism, and hence from mental resentment. This form of separation disturbs the equilibrium in qualities of thinking and in the daily lifestyle.

The interplay between perceptions and kleshas activates physiological demands on the organ systems, causing fur- ther degeneration (YS 1.5). This implies that perceptive behavior activates homeostatic regulations through neural and  hormonal  systems  that  enhance  the  physiological

response. In the presence of a klesha, the response is inten- sified, so the disease manifests. The klesha-associated per- ceptive response is the psyche behind the disease. To avoid persistent  homeostatic  disturbances,  YP  recommends restraining the perceptive interpretations.5  Restraining men- tal perceptions and beliefs moderates psychosomatic influ- ences, leading to disease prevention and health promotion. YP suggests that perceptions may influence individuals’ thought patterns and in turn their physiology.10    Advaita Vedanta, an Indian philosophical scripture, states that per- ception may generate fearful thoughts, for example, mistak- ing a rope for a snake.19 The fear may trigger the sympathet- ic nervous system to amplify the physiological response. Once the rope is recognized as a rope, parasympathetic activities follow. Hence, the present study explores psycho- somatic associations between frequencies of certain thought categories and aspects of life with PD. Resulting physiolog- ical changes that might have contributed to the onset and progression of PD will then be discussed.

This discussion complements epidemiological studies, which suggest that risk factors for PD include genetic fac- tors,20,21 environmental factors,22,23 intrauterine life, neonatal environment, and lifestyle influences.24,21 However,  in reviewing the epidemiological evidence, de Lau and Breteler25 report the cause of PD to be unknown. Past stud- ies have not been sufficiently robust in their methodology or broad enough. Whereas Western medical sciences exam- ine physical evidence, and especially external agents, in the causation of disease, the YP perspective examines and prior- itizes the role of the mind in the causation of disease. Therefore, this study draws on YP to expand investigation into plausible cognitive factors associated with the onset and progression of PD in New Zealand.


 This study sought to use survey methodology to investigate how thought patterns are associated with the level of PD severity among affected people in New Zealand. A cross- sectional postal survey was administered to a random sam- ple of members of Parkinson’s New Zealand (PNZ). Survey data were collected to (1) estimate prevalences of self- reported, retrospective thinking about aspects of life over the 4 weeks before the survey; and (2) explore associations between thought patterns and PD severity.

The sample selected comprised 990 of PNZ’s 4,500 registered members. This sample size was selected because we reasoned that a response rate as low as 30% would yield a sample of approximately 300 respondents, enabling esti- mation of a proportion as large as 0.5 with 95% confidence and a margin of error of ± 4.5%.26 We predicted a response rate of 30% because it was not known from the database

Yoga Perspective on Associations Between Thinking Patterns and Parkinson’s Disease which members have PD and speculated that those without PD might be less motivated to take part in the survey. PNZ performed the sample selection task to maintain the anonymity of its members. The selected members were invited to take part in the survey. Completed questionnaires and consent forms were mailed by participants to the authors at the University of Auckland, New Zealand.

The instrument contained questions about demograph- ics, PD severity, and frequency of thinking about 18 aspects of life identified in the literature to be commonly associat- ed with the kleshas.10,27–32 The latter questions were con- structed as 5-point Likert scales including never, seldom, sometimes, often, and always. Cleaned and coded data were entered into SPSS version 19.0 for statistical analysis. The Likert scales appeared to have face and content validity, and a principal component analysis (PCA) assessed the con- struct validity of the questions particularly relating to the aspects of thinking. The data were analyzed to show how PD varied by age group, sex, and whether the PD was self- reported to be mild, moderate, or severe. Later, patterns of thinking about different aspects of life were described. Kendall’s tau-b bivariate correlation coefficients were calcu- lated to test hypothesized associations between each aspect of thinking and the self-assessed severity of the PD. Cross- tabulations and partial correlations were also performed.



 Characteristics of Participant Groups

Of the invited sample of 990 members of PNZ, 35.4% (n= 357) returned usable questionnaires. Of these respon- dents, 319 (91.7%) self-reported having received a diagno- sis of PD from a health professional. The 29 (8.3%) who did not report receiving such a diagnosis were excluded from the study because they were too few in number to con- stitute a meaningful comparison group. The age of the respondents with PD ranged from 37 to 92 years. There were more males (60.4%) than females (39.6%) in this sam- ple. A majority of the PD respondents were aged at least 65 years (57.8%). Table 1 shows the self-reported severity of PD by respondents’ age and sex. Moderate to severe PD was reported  by  approximately  two-thirds;  this  level  of  PD severity was especially common among women and at ages 65 and over.

Aspects of  inking

The PCA with orthogonal rotation (Varimax with Kaiser normalization) indicated the construct validity of the 18 items about the frequency of thinking about different aspects of life. The PCA reduced these items to three com- ponents: intrapersonal, personal, and interpersonal aspects. The Kaiser-Meyer-Olkin (KMO) measure verified the sam- pling adequacy for the analysis (KMO 0.763), and all KMO values for individual items were between 0.138 and 0.649; however, two values were well above the acceptable limit of 0.5.33 Bartlett’s test of sphericity ( c2 (153) = 859.81, p < 0.0001) indicated that the correlations between items were significantly large for PCA. An initial analysis was run to obtain eigenvalues for each component in the data. Five components had eigenvalues above Kaiser’s criterion of 1 and in combination explained 52.4% of variance. The scree plot was slightly ambiguous and showed influxes that would justify retaining components 2 and 4. Given the large sam- ple and the convergence of the scree plot and Kaiser’s crite- rion on five components, this was reduced to three compo- nents in the final analysis.

Table 2 shows the component loadings after varimax rotation. The items that clustered on the same components suggest that components represented intrapersonal, person- al, and interpersonal thinking.

Table 3 shows the frequency with which respondents thought about 18 specified aspects of life over the previous 4 weeks (n = 319). Family was the aspect of life they report- ed thinking most about, with 87% of the respondents reporting “often” or “always” thinking about family. More than half of the respondents reported that they often or always think about health (65%), rest and sleep (57%), food (54%), and the future (52%). Death and sex were the aspects of life that the fewest respondents (17% and 20%, respectively) often or always thought about.

In contrast, work was the aspect of life that respondents reported thinking the least about; 48% reported “never” or “seldom” thinking about work. More than one-third of the

Table 1. Distribution of Parkinson’s Disease (PD) Group by Age, Sex, and Severity, n (%)


Male (n = 191) Female (n = 148)
Age < 65 y Age > 65 y Age < 65 y Age > 65 y
(n = 49) (n = 142) (n = 34) (n = 114)
Mild PD (n = 110) 23 (46.9) 44 (31) 14 (41.2) 29 (25.4)
Moderate to severe PD (n = 229) 26 (53.1) 98 (69) 20 (58.8) 85 (74.6)


International Journal of Yoga Therapy — No. 29 (2019)

Table 2. Principal Component Analysis, Rotated Component  Matrixa


Aspect of Thinking Intrapersonal Personal Interpersonal
Doing good deeds 0.744
Community 0.643
Being virtuous 0.634
Recreation 0.622
Exercise 0.602
Achievement 0.549
Family 0.401 0.364
Health 0.648
Rest and sleep 0.633
Death 0.602
Past 0.577
Future 0.385 0.388 0.306
Food 0.332
Sex life 0.764
Relationships 0.625
Work 0.551
Money 0.441 0.470
Holidays 0.349 0.399

aExtraction method = principal component analysis; rotation method = varimax with Kaiser normalization.





Aspect of Life

Never or Seldom  


Often or Always
Doing good deeds 19 50 31
Being virtuous 39 36 25
Recreation 15 46 39
Exercise 12 31 57
Achievement 19 47 34
Community 29 45 26
Family 2 11 87
Health 6 29 65
Rest and sleep 10 33 57
Death 42 41 17
Past 18 38 44
Future 10 38 52
Food 12 34 54
Sex life 45 35 20
Relationships 13 32 55
Work 48 24 28
Money 16 41 43
Holidays 33 41 26


Table 3. Frequency (%) of Thinking About Specified Aspects of Life

respondents reported that they never or seldom think about sex (45%), death (42%), and being virtuous (39%). Family and health were the aspects of life that the fewest respon- dents (2% and 6%, respectively) reported never or seldom thinking  about.



Table 4 presents Kendall’s tau-b bivariate correlation coeffi- cients between these thought patterns and PD severity. It shows a weak, but hypothesized positive, association (r = 0.2, p < 0.000) between PD severity and thinking about death. Other reported aspects of thinking showed no asso- ciation with the severity of PD, although this finding was only statistically significant for thinking about holidays (r = –0.1, p = 0.02).


PD Severity, Thinking About Death: By Sex and Age Table 5 illustrates exploration of the positive relationship between PD severity and thinking about death. Male and female respondents with mild PD reported thinking less about death than did those with moderate to severe PD. Thinking often or always about death was almost twice as common among those whose PD was moderate to severe rather than mild. This pattern was strongest among men. Thinking often or always about death by men with moder- ate to severe PD was 6 times as common compared to men with mild PD.

For all respondents with moderate to severe PD, those aged > 65 years reported thinking about death often or always 6 times more commonly than those aged less than

  1. One-third of the older respondents with moderate to severe PD reported never or seldom thinking about death, compared with half of those aged less than 65.

Assuming an underlying metric to the ordinal data, the zero-order correlation coefficient between PD severity and thinking about death was calculated. The result was similar to that reported in Table 5. A weak, but hypothesized posi- tive, association was found: r = 0.23; p < 0.000. After adjustment for sex and age, the partial correlations fell to

0.17 and 0.14, respectively.

Mo re males than females and considerably more European New Zealanders with PD responded to the sur- vey. Reported thinking was most commonly around family and health, whereas thinking about sex life and death was least common. The PCA showed that the thinking patterns fell into three distinct groups related to intrapersonal, per- sonal, and interpersonal thinking. However, the bivariate correlation showed a weak but positive association between disease severity and thinking about death. Further cross- tabulations showed that more women than men with severe PD, aged at or above 65, thought frequently about death.

Yoga Perspective on Associations Between Thinking Patterns and Parkinson’s Disease

Table 4. Kendall’s Tau-b Bivariate Correlation Coefficients




Aspect of life


Predicted Direction of Correlation


Correlation Coefficient

95% Confidence Interval of the Difference  


p Value

Lower Upper
Work Positive –0.09 2.4889 2.7684 0.06
Money Positive 0.00 3.2337 3.4266 0.85
Relationships Positive –0.00 3.4035 3.6124 0.92
Health Negative 0.16 3.6181 3.8014 0.01
Death* Positive 0.21 2.5966 2.7914 0.00
Food Negative –0.00 3.3520 3.5404 0.91
Sex life Positive –0.06 2.5108 2.7321 0.22
Holidays* Negative –0.11 2.7509 2.9697 0.02
Family Positive 0.00 4.1259 4.2792 0.93
Community Positive –0.08 2.8406 3.0380 0.08
Exercise Negative –0.05 3.4319 3.6217 0.24
Recreation Negative –0.08 3.1359 3.3207 0.10
Past Positive 0.08 3.1920 3.3794 0.11
Future Negative 0.03 3.3943 3.5769 0.47
Doing good deeds Positive 0.05 3.0456 3.2274 0.28
Being virtuous Negative 0.02 2.6849 2.9177 0.68
Achievement Negative –0.03 3.0823 3.2647 0.48
Rest and sleep Negative 0.09 3.4407 3.6226 0.05

*Statistically significant associations.


Table 5. Cross-Tabulation of Parkinson’s Disease (PD) Severity and Thinking About Death, According to Sex and Age



PD Severity

Thinking About Death, n (%)
Never or Seldom Sometimes Often or Always


Male Mild 37 (57.0) 24 (37.0) 4 (6.0)
Moderate to severe 57 (45.0) 46 (36.5) 23 (18.0)
Female Mild 17 (41.5) 17 (41.5) 7 (17.0)
Moderate to severe 21 (25.0) 44 (52.5) 19 (22.5)


< 65 y Mild 20 (56) 12 (33) 4 (11)
Moderate to severe 20 (50) 14 (35) 6 (15)
> 65 y Mild 33 (48) 29 (42) 7 (10)
Moderate to severe 53 (33) 70 (44) 36 (23)


 Although proportionally more women than men in the gen- eral population survive to the older ages at which PD is most common, males accounted for three-fifths of our respondent sample of people with PD. Buetow et al.34 sim- ilarly reported that 57% of the respondents to their nation- al-sample survey of PNZ members were men. A meta- analysis of 17 relevant studies yielded a sex ratio of 1:5 (95% confidence interval 1.2–1.7).35 In addition, 57.8% of our sample was at least 65 years old, and respondents were almost exclusively New Zealand European, most likely because PNZ’s membership is disproportionately New Zealand European. The majority of the respondents report- ed having PD of mild to moderate severity. Comments from caregivers were consistent with this self-assessment because the people with severe PD were reported by their

caregivers to be unable to take part in the survey, owing, for example, to dementia. The respondents thought most about family and least about work. They thought often or always about health, food, the future, and rest and sleep. The aspects of life they seldom or never thought about were death, sex, and being virtuous.

As hypothesized, a statistically significant positive cor- relation (r = 0.2, p < 0.000) was found between thinking about death and the severity of PD. The participants with mild PD reported seldom thinking about death. The partic- ipants with moderate PD thought sometimes about death, and the group with severe PD thought often about death. Thinking about death was also more common at older ages (> 65 years), and women tended to think more about death in comparison to the men. The participants with severe PD had the highest frequency of always thinking about death, which  may  be  due  to  the  debilitating  nature  of  PD.

International Journal of Yoga Therapy — No. 29 (2019)

However, in accordance with YS, the klesha of fear/thinking about death or wanting to live (abhinivesha) could be a cause, and not merely a consequence, of PD progression.

Fear/thinking about death may be due to an individ- ual’s reflection on past calamities such as death in the fami- ly, disease, natural disasters, wars, famine, and accidental deaths. Such events could provide strong motivation to cre- ate a safe life.7 In these terms PD progression may be influ- enced by abhinivesha, the fifth affliction according to YS. The greater the thinking about—and possibly fear of— death, the more persistent the activation of the associated cognitive neural pathways. The result could be increased metabolic activity and adaptive degeneration. Hence, think- ing about death is a possible cause of the progression of PD. The positive association found between PD severity and thinking about death could mean that people  with  PD think increasingly  about death once their PD becomes severe and the specter of death approaches. However, think- ing frequently about death may (also) accelerate the pro- gression of PD, as this assumption is consistent with YP and is feasible in neurophysiological terms.


 Our cross-sectional sample of members of PNZ with PD thought frequently about family, health, rest and sleep, food, and the future; they thought least about work, sex, death, and being virtuous. When aspects of thinking were correlated with the self-reported severity of PD, the only (weakly) positive and statistically significant correlation was with thinking about death, even after controlling for age and sex.

YP recognizes that when a klesha (mental affliction) is associated with behavior, it causes suffering. Key aspects of YP concern the subconscious behaviors that go unnoticed by the individual yet guide actions on a daily basis. When a klesha is present, it translates into every aspect of life. It has been speculated that the progression of PD is associated with a klesha, namely fear of death. When a fear of death is present, a particular neural corridor is overactive due to action selection and reinforcement learning, leading to its degeneration.

This study was unable to assess the trustworthiness of responses and validate respondents’ self-report of a PD diag- nosis. We also could not determine whether thinking about death was a cause or consequence of PD severity, and whether the pattern commenced before PD symptoms manifested. However, premorbid studies have agreed that people with PD have a personality trait of restraint. From a YP perspective, restraint indicates being fearful. Moreover, the possibility that thinking about death accelerates PD progression is consistent with neurophysiological mecha-

nisms associated with the mind-body connection. Therefore, our tentative conclusion is that the more the fear of death is present, the more the disease progresses into a severe state. People with PD should perhaps aim not to think about their own death. Fortunately, thinking about death, as a risk factor for PD progression, appears uncom- mon in our sample.

Preliminary findings indicate a need for further investi- gations from a YP perspective into how pre- and postmor- bid cognitive behavior and associated kleshas may cause and accelerate the progression of PD. We recommend further examination of these findings through a retrospective cohort study to validate our findings and elucidate the tem- poral ordering of a fear of death and the etiology and pro- gression of PD. Qualitative research is also needed to under- stand why thinking about death appears to increase as PD worsens.



We thank the patients who participated in this survey, and their families and caregivers. This study was supported by Parkinson’s New Zealand; the School of Population Health, University of Auckland, New Zealand; and the Wellpark College of Natural Therapies, Auckland, New Zealand.

Conflict-of-Interest  Statement

There are no conflicts to declare.


 Dorsey, R., Constantinescu, R., Thompson, J. P., Biglan, K. M., Holloway,

  1. G., Kieburtz, K., . . . Tanner, C. M. (2007). Projected number of people with Parkinson disease in the most populous nations, 2005 through 2030. Neurology, 68(5), 384–386.
  2. Saraswati, S. (2006). Four chapters on freedom: Commentary on the yoga sutras of Patanjali. Bihar, India: Yoga Publication Trust.
  3. Karambelkar, V. (2012). Patanjala yoga sutra: Sanskrit sutra with translitera- tion, translation and commentary. Lonavala, India: Kaivalyadhama.
  4. Braud, (2010). Patanjali Yoga Sutras and parapsychological research: Exploring matches and mismatches. In K. R. Rao (Ed.), Yoga and parapsychology: Empirical research and theoretical studies (241–260). Delhi, India: Motilal Banarsidass.
  5. Hill, (2007). Yoga sutras: The means to liberation. Victoria, Canada: Trafford Publishing.
  6. Lipton, (2005). The biology of belief. Santa Rosa, Calif.: Mountain of Love/Elite Books.
  7. Gluckman, D., & Hanson, M. A. (2004). Living with the past: Evolution, development, and patterns of disease. Science, 305(5691), 1733–1736.
  8. Stout, (2011). Stone toolmaking and the evolution of human culture and cognition. Philosophical Transactions of the Royal Society B: Biological Sciences, 366(1567), 1050–1059.
  9. Ajita, Y. (2010). Raja Yoga—The yoga sutras of Patanjali. Ilpendam, Holland: The Raja Yoga Institute.
  10. Cannon, B. (1939). The wisdom of the body (2nd ed.). Oxford: Norton & Co.
  11. Cohn, (2002). From the field—Mahamudra disability: Ancient India- Tibetan social theory. Disability Studies Quarterly, 22(2). doi:


Yoga Perspective on Associations Between Thinking Patterns and Parkinson’s Disease

  1. Belleau, -C., & Johnson, R. (2007). Faces of judicial anger: Answering the call. In M. Jézéquel & N. Kasirer (Eds.), Les sept péchés capitaux et le droit (13–56). Montreal: Thémis.
  2. Palsane, N., & Lam, D. J. (1996). Stress and coping from traditional Indian and Chinese perspectives. Psychology & Developing Societies, 8(1). doi:
  3. Sivakumar, , & Rao, U. (2009). Building ethical organisation cultures- Guidelines from Indian ethos. International Journal of Indian Culture and Business Management, 2(4), 356–372.
  4. Koay, , & Barenholtz, T. (2010). The science and philosophy of teaching yoga and yoga therapy. Sun Yoga Press.
  5. Frawley, (2006). Yoga and the sacred fire. Delhi, India: Motilal Banarsidass.
  6. Anderson, (2012). An investigation of moksha in the advaita vedanta of Shankara and Gaudapada. Asian Philosophy, 22(3), 275–287.
  7. Haubenberger, , Reinthaler, E., Mueller, J. C., Pirker, W., Katzenschlager, R., Froehlich, R., . . . Zimprich, A. (2011). Association of transcription factor polymorphisms PITX3 and EN1 with Parkinson’s disease. Neurobiology of Aging, 32(2), 302–307.
  8. Gatto, M., Rhodes, S. L., Manthripragada, A. D., Bronstein, J., Cockburn, M., Farrer, M., & Ritz, B. (2010). a-Synuclein gene may interact with environmental factors in increasing risk of Parkinson’s disease. Neuroepidemiology, 35(3), 191–195.
  9. Aitlhadj, , Ávila, D. S., Benedetto, A., Aschner, M., & Stürzenbaum, S. R. (2010). Environmental exposure, obesity, and Parkinson’s disease: Lessons from fat and old worms. Environmental Health Perspectives, 119(1), 20–28.
  10. Willis, W., Evanoff, B. A., Lian, M., Galarza, A., Wegrzyn, A., Schootman, M., & Racette, B. A. (2010). Metal emissions and urban incident Parkinson disease: A community health study of Medicare beneficiaries by using geographic information systems. American Journal of Epidemiology, 172(12), 1357–1363.


  1. Sanyal, , Chakraborty, D., Sarkar, B., Banerjee, T., Mukherjee, S., Ray, B.,

& Rao, V. R. (2010). Environmental and familial risk factors of parkinsons dis- ease: Case-control study. The Canadian Journal of Neurological Sciences, 37(5), 637–642.

  1. de Lau, M. L., & Breteler, M. (2006). Epidemiology of Parkinson’s dis- ease. The Lancet Neurology, 5(6), 525–535.
  2. Raosoft, (2004). Sample size calculator. Retrieved from:
  3. Digambarji, , & Gharote, M. (2004). Gheranda samhita. Lonavala, India: Kaivalyadhama.
  4. Iyengar, K. S. (2004). Light on the yoga sutras of Patanjali. London: HarperCollins Publishers.
  5. Maheshananda, , Sharma, B., Sahay, G., & Bodhe, R. (2005). Vasistha samhita. Lonavala, India: Kaivalyadhama.
  6. Muktibodhananda, (2000). Hatha yoga pradipika. Bihar, India: Yoga Publications Trust.
  7. Svatmarama,, & Sinh, P. (2002). Hatha yoga pradipika. Woodstock, N.Y.:
  8. Swarupananda, (2016). Srimad bhagavad gita. Kolkata, India: Advaita Ashrama.
  9. Field, P. (2009). Discovering statistics using SPSS (3rd ed.). London: SAGE Publications Ltd.
  10. Buetow, , Giddings, L. S., Williams, L., & Nayar, S. (2008). Perceived unmet needs for health care among Parkinson’s Society of New Zealand mem- bers with Parkinson’s disease. Parkinsonism & Related Disorders, 14(6), 495–500.
  11. Taylor, , Cook, J., & Counsell, C. (2007). Heterogeneity in male to female risk for Parkinson’s disease. Journal of Neurology, Neurosurgery & Psychiatry, 78(8), 905–906.