"Well, when I was a young boy, only 13, I was badly hurt in an IRA bombing in London. My left hand had to be amputated after the explosion, and I knew I’d lived through a psychological stress that most people cannot even conceive. I would definitely say this triggered my interest in altered states. When you lose a limb, especially when the limb is exposed to serious trauma before the loss, there is a significant chance you’ll be left with an agonizing phantom limb.
...
It’s a complete bastard to treat. God knows how many drugs I’ve been prescribed. Antidepressants, anti-epileptics, muscle relaxants—none of them really worked. For the worst excesses of phantom-limb pain, traditional painkillers like opiates don’t even touch it. You might as well not even bother with them. I was prescribed high doses of pethidine [also known as Demerol] but returned the bottle to my doctor because it wasn’t doing me any good whatsoever. When I came back, my doctor was agog. He said, “Nobody returns pethidine!” The pain involved can be so bad as to effectively detach your mind from consensus reality. Without suitable analgesia I end up looking like a psychiatric inmate, just rocking backward and forward, unable to do anything, sometimes for more than a day. All that considered, anything that does work is an absolute godsend.
And what works?
I discovered a long time ago that ketamine and cannabinoids helped my phantom hand. I’m quite convinced these classes work by distorting body image so severely that you phase out triggers for the pain. I have experienced profound proprioceptive distortions after intramuscular PCP injection, as if my whole body were a proportional model of the sensory homunculus. But in a sense, what I feel is not hallucination or a distortion, I actually find dissociatives corrective, that is, they make the phantom disappear. This is not just an idiosyncratic response on my part; there are at least three articles published on the effectiveness of ketamine in treating phantom-limb pain."
https://www.vice.com/en_us/article/ppzgk9/interview-with-ketamine-chemist-704-v18n2
...
It’s a complete bastard to treat. God knows how many drugs I’ve been prescribed. Antidepressants, anti-epileptics, muscle relaxants—none of them really worked. For the worst excesses of phantom-limb pain, traditional painkillers like opiates don’t even touch it. You might as well not even bother with them. I was prescribed high doses of pethidine [also known as Demerol] but returned the bottle to my doctor because it wasn’t doing me any good whatsoever. When I came back, my doctor was agog. He said, “Nobody returns pethidine!” The pain involved can be so bad as to effectively detach your mind from consensus reality. Without suitable analgesia I end up looking like a psychiatric inmate, just rocking backward and forward, unable to do anything, sometimes for more than a day. All that considered, anything that does work is an absolute godsend.
And what works?
I discovered a long time ago that ketamine and cannabinoids helped my phantom hand. I’m quite convinced these classes work by distorting body image so severely that you phase out triggers for the pain. I have experienced profound proprioceptive distortions after intramuscular PCP injection, as if my whole body were a proportional model of the sensory homunculus. But in a sense, what I feel is not hallucination or a distortion, I actually find dissociatives corrective, that is, they make the phantom disappear. This is not just an idiosyncratic response on my part; there are at least three articles published on the effectiveness of ketamine in treating phantom-limb pain."
https://www.vice.com/en_us/article/ppzgk9/interview-with-ketamine-chemist-704-v18n2