here is an interesting angle to the question. as far as i know/have seen/tried, there is only one way to get thc alone, and its pretty expensive and not very common (thc diamonds). shatter, hash and all the other concentrates are full spectrum extracts so they contain whatever cbd (and other stuff) that was in the flower. in my experience with diamonds, i would say they are likely not the best at pain reduction on their own. whenever i try diamonds i just feel like i took the pill from that movie 'limitless'
people usually mix them with 'sauce' which is all the terpenes and other cannabinoids that separate from the diamonds when they are being made...which brings back in all the expected effects that come with them.
i find its both. there is definitely actual/traditional/medicinal pain reduction taking place. it will never take all the pain away, but it will turn the volume knob from a ten to a four, which is a vast improvement for someone who lives like that 24/7. the other aspect is distraction...if you can catch a break for a couple hours giggling at the tv or lost in a book/album/game/conversation, thats a couple hours of recovery from all the stress and misery of living with whatever condition is causing all the pain/problems...and thats an extremely valuable couple hours. there is science to back up the old saying 'laughter is the best medicine'...so try to do it as much as possible