Friday, March 25, 2011

About the anti-anxiety benefits of yoga

Strike a Pose to Reduce Anxiety

By Jennifer Gibson, PharmD, practicing clinical pharmacist and freelance medical writer.

Source: BrainBlogger, a biomedical blog that covers topics from multidimensional biopsychosocial perspectives.

Yoga is a practice almost as old as time itself. It combines mental and physical elements that people today use to enhance spirituality, exercise, decrease stress, and increase well-being. While many practitioners of yoga seem almost mystical and more philosophical than the average bear, a new study proves that you need not be a yogi to achieve the anti-anxiety benefits of yoga.

Research published in the Journal of Alternative and Complementary Medicine reports that practicing yoga postures increased the levels of gamma-aminobutyric acid (GABA) in the brain. (GABA is a neurotransmitter in the central nervous system that is responsible for reduced anxiety, increased relaxation, and enhanced muscle tone.) In this study, healthy subjects with no significant physical or psychiatric illnesses or conditions participated in 60-minute yoga sessions 3 times weekly for 12 weeks. Alternatively, a comparison group participated in a metabolically matched walking program for the same length of time. Subjective mood and anxiety measurements were recorded, and magnetic resonance spectroscopy scans were completed at baseline and at 12 weeks.

Overall, yoga participants experienced greater improvement in mood and decrease in anxiety, compared to the walking group. More objectively, yoga participants showed increased levels of GABA in the brain. Positive correlations were observed between improved mood and decreased anxiety and GABA levels. This appears to be the first time that long-term behavioral interventions have produced increased GABA levels. (A similar pilot study showed that a single yoga session increased GABA levels.) Pharmacological agents are frequently used to increase GABA activity in order to reduce anxiety and improve mood. Yoga, in contrast to pharmacological agents, carries almost no risk of adverse consequences and costs very little, if anything, to practice.

In addition to decreasing anxiety, yoga and other mindfulness-based techniques improve stress, depression, overall well-being, neuroticism, eating habits, energy levels, and pain. Yoga has been prescribed for arthritis and other joint and muscle disorders, with strikingly positive benefits. Yoga also promotes immune function, weight loss, decreased heart rate and blood pressure, and muscle strength. Yoga has even been shown to decrease premature delivery when practiced by women during pregnancy. While other forms of exercise bring about the same benefits, yoga has shown more robust benefits than other activities.

With seemingly all the benefits and none of the risks, yoga should be explored as part of a treatment plan for individuals with mood and anxiety disorders. Or, for anyone wishing to improve well-being. So, grab a yoga mat and strike a pose. Namaste.

References

  • Field T (2011). Yoga clinical research review. Complementary therapies in clinical practice, 17 (1), 1-8 PMID: 21168106
  • Haaz S, & Bartlett SJ (2011). Yoga for arthritis: a scoping review. Rheumatic diseases clinics of North America, 37 (1), 33-46 PMID: 21220084
  • Smith BW, Shelley BM, Dalen J, Wiggins K, Tooley E, & Bernard J (2008). A pilot study comparing the effects of mindfulness-based and cognitive-behavioral stress reduction. Journal of alternative and complementary medicine (New York, N.Y.), 14 (3), 251-8 PMID: 18370583
  • Streeter CC, Jensen JE, Perlmutter RM, et al. Yoga Asana sessions increase brain GABA levels: a pilot study. J Altern Complement Med. May 2007;13(4):419-426. PMID: 17532734
  • Streeter CC, Whitfield TH, Owen L, Rein T, Karri SK, Yakhkind A, Perlmutter R, Prescot A, Renshaw PF, Ciraulo DA, & Jensen JE (2010). Effects of yoga versus walking on mood, anxiety, and brain GABA levels: a randomized controlled MRS study. Journal of alternative and complementary medicine (New York, N.Y.), 16(11), 1145-52 PMID: 20722471

Monday, March 21, 2011

Somatic markers - how the body affects the mind

Your somatic markers know when to hold ‘em

By Lorimer Moseley in Body In Mind:Research into the role of the brain and mind in chronic pain, 21 March 2011


There is a very large body of data that show that the body affects the mind. That is, bodily processes and responses to stimuli affect our thoughts about those stimuli and our behavioural responses to them. Some of the most intriguing research in this area has been done by Antonio Damasio – most famously the Iowa gambling project [1]. They have primarily investigated people who have damage to their emotional system – ventromedial prefrontal cortex - yet seem to function very well on language and intelligence tests. They do, however, act in a socially inappropriate manner and make stunning judgement errors. One of the earliest studies showed that while healthy volunteers began to choose advantageously before they worked out which strategy was in fact advantageous, patients with damage to their prefrontal lobe chose disadvantageously the whole time – even if they had worked out which strategy was in fact advantageous. The study also showed that normals would have a galvanic skin response, a sign of sympathetic activation, before they realised they were about to make a risky choice. Damasio’s group has done a bunch of studies that underpin their Somatic Marker Hypothesis – “Somatic markers are events or chemicals in your body, detection of which evokes particular feelings or emotions. A note here that, according to Damasio – check out his very readable book ‘The feeling of what happens’, emotions are brain representations of body states. That is, you see a scary looking man approaching you, your sympathetic nervous system is activated, this sends feedback to your brain and your brain registers this feedback and you feel frightened). So, the essence of the somatic marker hypothesis is that when a “negative somatic marker is linked to a particular future outcome it becomes an alarm bell and when a positive somatic marker is linked to a particular future outcome it becomes an incentive” [2].


So, people who have damage to the part of the brain that registers feedback from the somatic markers, don’t ‘read the signals’ from their internal environment. The somatic marker hypothesis argues that this is why they make errors of judgement and do socially inappropriate things – they can’t process the shift in the somatic markers. So, next time you join the poker game, remember what the somatic marker hypothesis says: it is your body that tells you when to hold ‘em, when to fold ‘em, when to walk away and when to run, not Kenny Rogers. So, clearly there is bottom-up influence on cognition – the embodied cognition people talk about this a great deal. We have shown (see here for BiM discussion on ‘Rubber Hand makes your real hand go colder‘ and visual distortion) a top-down effect of cognitive representations on the body [3, 4]. The next blog will raise the stakes even further, albeit rather speculatively…..

1. Bechara, A. (1997). Deciding Advantageously Before Knowing the Advantageous Strategy Science, 275 (5304), 1293-1295 DOI:10.1126/science.275.5304.1293

2. Damasio AR (1996). The somatic marker hypothesis and the possible functions of the prefrontal cortex. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 351 (1346), 1413-20 PMID: 8941953

3. Moseley, G., Olthof, N., Venema, A., Don, S., Wijers, M., Gallace, A., & Spence, C. (2008). Psychologically induced cooling of a specific body part caused by the illusory ownership of an artificial counterpart Proceedings of the National Academy of Sciences, 105 (35), 13169-13173 DOI: 10.1073/pnas.0803768105

4. Moseley, G., Parsons, T., & Spence, C. (2008). Visual distortion of a limb modulates the pain and swelling evoked by movement Current Biology, 18 (22) DOI:10.1016/j.cub.2008.09.031

Tuesday, March 15, 2011

On chronic pain and body schema

Pain: The Science and Culture of Why We Hurt

by Marni Jackson

"Why do we still distinguish between mental pain and physical pain," she asks, "when pain is always an emotional experience? Why is pain so poorly understood, especially in a century of self-scrutiny? Hasn't anyone noticed the embarrassing fact that science is about to clone a human being but still can't cure the pain of a bad back?"

A new take on the Gate Control Theory, or, The benefits of rubbing your boo-boos

from the blog of Dave Walton, physiotherapist and Assistant Professor with the School of Physical Therapy at University of Western Ontario.

" ... (I)t is conceivable that the brain's sentry body-self neuromatrix maintains that heightened state of arousal and sensitivity in it's efforts to obtain knowledge about the state of the painful part. This might also be the mechanism behind Peter O'Sullivan's observations that some people with chronic low back pain exhibit behaviours that result in further pain (ie. it's painful to extend the lumbar spine, but some people habitually adopt this posture despite the pain). In that case, this theory would suggest that any stimuli coming from the area, even if unpleasant, can offer at least some form of relief to a neuromatrix seeking information, especially in those conditions that you can't see. Not saying this is good, just saying it makes sense in light of my pseudo-theory. Note that this theory would also support the notion that manual therapies probably have much of their effect through drawing attention to, and providing neurophysiological stimulus from, painful parts of the body. The focus on identifying very specific movement impairments (ie. restricted superior glides of the facet) becomes less of a priority than does identifying the amount of stimulus that can be applied to a body in pain that provides adequate stimuli without being perceived as threatening to the sensitized 'pain' system."

I can't find it! Distorted body image and tactile dysfunction in patients with chronic back pain

By G. Lorimer Moseley

ABSTRACT: The conscious sense of our body, or body image, is often taken for granted, but it is disrupted in many clinical states including complex regional pain syndrome and phantom limb pain. Is the same true for chronic back pain? Body image was assessed, via participant drawings, in six patients with chronic back pain and ten healthy controls. Tactile threshold and two-point discrimination threshold (TPD) were assessed in detail. All the patients, and none of the controls, showed disrupted body image of the back. Five patients were unable to clearly delineate the outline of their trunk and stated that they could not “find it”. TPD was greatly increased in the same zone as the absence or disruption of body image, but was otherwise similar to controls. The disturbance of body image and decrease in tactile acuity coincided with the normal distribution of pain, although there was no allodynia and there was no relationship between resting pain level and TPD. Tactile threshold was unremarkable for patients and controls. These preliminary data indicate that body image is disrupted, and tactile acuity is decreased, in the area of usual pain, in patients with chronic back pain. This finding raises the possibility that training body image or tactile acuity may help patients in chronic spinal pain, as it has been shown to do in patients with complex regional pain syndrome or phantom limb pain.


Friday, March 4, 2011

Ruled by the Body: How Physical Illness Affects the Brain

'Many common ailments and physical conditions can influence the brain, leaving you depressed, anxious or slow-witted.' says Erich Kasten,professor of medical psychology at the University of Lbeck in Germany in an article that appeared in Scientific American on March 3, 2011.

According to Kasten, doctors often forget to ask patients about psychological symptoms. Conversely, psychologists and psychiatrists may treat mental troubles in isolation without looking for a physical cause. But now some doctors and psychologists are reviving the decades-old discipline of somatopsychology, which centers on the effects of physical illness on the brain.

'In Western culture people have long treated body and mind as separate. This dichotomy, popularized by French philosopher René Descartes in the 17th century, is still reflected in medical practice, as the specialists who look after our bodies remain different from those who attend to our psyches. Of course, the division has blurred in recent decades. We now know, after all, that the mind is housed in a physical entity, the brain, which is part of the body. And most people are also aware that psychological problems can produce physical symptoms in the form of psychosomatics; for instance, mental stress can spawn headaches, an upset stomach or even heart problems.

'But fewer people appreciate that the influence also runs in the other direction—that changes in your body can profoundly perturb your mental state,' he says.

Full article available at Scientific American website