we know 4 people who overdosed on LSD<LYSERGICACID> and never camedown. after about 6 month 2 were able to be tought ways to manage the halluctions, and even ignore them sometimes, but once in while these two would go back into another world. the other two took more time and were alot less manageable.
medicine did not help these 4 people we know one bit.one is still a good friend of ours, even succesfull desipte always being in a permahigh, he spent 8 month in the lunny bin though before treatment could even begin.I dont know if these cases had been less severe if medice would have helped though.
my best advice is you will just have to weight this out,but he is as you say,STUCK,sorry.LSD is the olny drug that I know that can do this to someone,not saying its the olny though, perhaps he did meth that was laced with lsd and did more of it later on and eneded up oding on the lsd.
infact lsd was used as a chemical wepon during ww1 becuse of its ability to produce this permahigh.