It may or may not be. Nobody knows the whole science, it accrues too fast for people to keep track of it. Maybe some PhD somewhere out there wrote a paper about a chemical or therapy that would solve GP's problems. Or maybe it will exist in 10 years. Or maybe never.

I assume GP did a lot of searching and experimentation, and haven't found a solution. From my own experience I can tell that the process of searching itself is very draining, especially if your trial-and-error has to involve help from a specialist at each step. So at some point one just figures out a coping strategy and cuts their losses.