Interestingly enough the brain reacts to spicy food as actual pain, like that spicy burny sensation you get in your mouth tricks the brain into thinking you're in extreme pain so it releases its natural opiates...probably why its hard to stop eating salsa once you start no matter how much your mouth burns, or how much indigestion you get.

But that is more of an uplifting feeling than I get with the disassociation...but maybe eating something spicy(or doing anything else that could cause the brains natural opiates to release) when you aren't on edge or experiencing symptoms causes more good feeling effects of the brains opiates...but if you're having symptoms and go numb or disassociate it doesn't reach that point because its just taking the edge off or whatever rather then being in a 'healthy' state and having the brain release those. I actually once tried clearing up an ongoing stuffy nose I had for a while with cayenne pepper by sniffing a little bit it burnt but sort of helped me breath better and the feeling after that was kind of nice actually nose felt all numb after the burning sensation went away and mentally I felt quite calm( I know sounds like one of those idiotic things bored kids might do to try to get 'high' but that experience is what it is). But I'm not a neurologist just my thoughts and experience on the topic.