That patent is just on synthesis, not usage and well past its use-by date now. I expect if the research on psychedelics is eventually honoured, big companies will patent their therapeutic use with depression, whole new patents for however many years they go for these days.
Psilocybin is possibly better than all these but has no patent. In fact did they study any drugs that were out of patent? Probably not.
Yes, they did, but it worked so well, it can cure, (and is fairly easy to make) that it became illegal.
That patent is just on synthesis, not usage and well past its use-by date now. I expect if the research on psychedelics is eventually honoured, big companies will patent their therapeutic use with depression, whole new patents for however many years they go for these days.