Sufis and Christian and Jewish mystics also have practises which can help, then there is the TM crowd too. Meditation takes care of about 85 per cent of my muscle spasm and I think it must make the nerve pain more susceptible to acupuncture and other things like that, and I have personally witnessed a yoga expert move objects on a desktop from four metres away, which would be a useful skill for any chronic pain patient, but consider the body makes endorphins but not always enough of them -- I consider morphine and so forth to be vitamins and when one gets to decades of use of narcotics, I don't think it is ever possible to return to the pre-injury/disease baseline and the attempt would be cataclysmic and make the depression which bedevils far too many of our fellow humans look like a walk in the park, and even more misunderstood. That is if one does not have a heart attack, stroke of apoplexy, pulmonary embolism, or pancreas failure during the acute withdrawal. Then there is always the awful spectre of Selbstvernichtung . . .
After 30, 50, 65, 100 years on narcotics, when every single cell in the body has replaced itself at least ten times, I am not sure just what the body would have to do to get back to the standard operating procedure when we were born and the brain finished developing 25 years later. I'll combine the meditation, holotropic breathing, the Big M and relatives and everything else and hopefully live to well over 100 as did two of my grandparents in similar circumstances, and the elderly American lady I knew who was put on smack, then morphine for Potts Disease inter alia six years before the Harrison Narcotic Act 1914 and lived to see Barack Obama take the oath of office in 2009. To this day, there are still Germans and Austrians still alive who have been on the Big M and its relatives since before the Opiumgesetz 1929 and Suchtgiftverordnung 1931.
Then benzodiazepines are another kettle of fish - they could have the same effect if there was never a supply interruption and tolerance did not get out of hand, but their low toxicity gives some wiggle room there.