Mind-body therapy for choric pain
Centrally maintained pain has been correlated with cortical plasticity, which refers to the theory that the brain can undergo neurological changes with time, in correlation with sensations of chronic pain (Flor et al., 1997; Knost et al., 1997).
The connection between the mind and the body is particularly significant in the realm of treating chronic pain. For many patients, the addition of a mind-body approach to treating chronic pain leads to a significant improvement in quality of life. Chronic pain patients who completed an 8-week mindfulness-based stress reduction (MBSR) program significantly improved their pain symptoms and overall quality of life, even up to four years after completion of this initial training (Kabat-Zinn et al., 1985).
8 weeks of mindfulness training significantly improved pain symptoms in irritable bowel syndrome (IBS) patients, even after three months of training. Mindfulness meditation reduced pain symptoms by reducing anxiety and emotional reactions to IBS symptoms (Garland et al. 2011).
After 3-4 months of Yoga sessions, back pain (Sherman et al., 2005; Williams et al., 2005), rheumatoid arthritis (Evans et al., 2010), and headache (John et al., 2007) were significantly reduced. Yoga participants after 12 weeks of weekly classes reported less pain killer use than the waiting list control group (Saper et al., 2009).
Yoga has also been effective for osteoarthritis of the hands and knees. After once weekly Yoga sessions for 8 weeks, the participants experienced less pain, and improved physical functions (Garfinkel et al., 1994; Kolasinski et al. 2005).
Placebo analgesia is partly mediated by the endogenous opioid system (Amanzio et al., 1999; Sauro et al., 2005). Among the modulating mechanisms of placebo analgesia, it is postulated that the expectation of lessening of pain stimulates production of endogenous opioids (Teixeira et al. 2010).
Placebo analgesia is typically preceded by greater activation of the PFC during anticipation of pain, an effect that predicts reductions in pain perception and activity in pain-related brain regions (Petrovic et al. 2011). Positive expectations concerning analgesia would stimulate the dorsolateral PFC, which would then simultaneously activate the medial PFC, the orbito-frontal PFC and the opioid system of the brain (PAG) (Fricchione et al., 2005). ACC has been postulated to attenuate pain by employing cognitive control mechanisms to modulate pain through activation of the descending opioid system via the PAG.
Wager et al. (2004) observed a decrease in pain with the application of a placebo cream on the arms of patients subjected to electric shocks, coinciding with an increase in brain activity in the orbito-frontal PFC, dorsolateral-medial PFC, and PAG (Wager et al. 2004).
Similarly, spoken suggestion-induced placebo analgesia showed the decrease of neural activity in the thalamus, and ACC with a simultaneous increase in the lateral amygdale and PAG in patients with IBS (Price et al. 2007). Thus, it is likely that positive expectation activates endogenous opioids and pain-modulating brain networks, resulting in inhibition of pain pathways.